Fuel Gauge errors, Hesitation/Surge/Stall..
05-17-2009, 01:45 AM
#1
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Join Date: May 2009
Posts: 95
Hesitation/Surge/Stall..
1997 Z28...was running great for 2 years, ran over a dead animal which sent tranny code...had it fixed...took it back due to leak and now it doesn't "lock" into the positions...but was tired of taking it back... runs fine for another 2 years....last summer I ran out of GAS...then went up north and had about 3/4 of a tank or less in it according to the gauge?...ran out of gas...you could literally watch the gauge drop....have watched it constantly since and it seems to stay at full/overfull to 3/4 for 50+ miles and then rapidly drops from 3/4 to nothing? I did awhile ago smell gas by the rear driver's side tire and looked under the vehicle for any signs of leaking gas..nothing on the ground or the tank...
Now I have been driving it since march and I noticed some hesitation/surging building upon heavy acceleration... I lined up at a light by some guy we both floored it...I accelerated smoothly up to about 60mph where it seemed to almost die...then whiplash it surged...I have watched it and the rpms are going to the redline when this happens... I decided to change the oil and clean my k&n air filter and found the k&n was very dirty and had actually fallen off.... I cleaned it very amateurishly figuring it would take it over to some guy my dad knows to get it checked out in the next few days... I let it dry over a day...and drove it about 2 miles each way one day no problem...the next day I drove to the exact same place but this time upon pulling out of the parking spot I got straightened out and then the car stalled...I restarted and it stalled....I did this repeately...it wouldn't start but I am almost 100% sure it's not the starter, I've replaced them before on other cars and heard clicking, one time it made a funny noise like a misfire and died out after running real rough for a few seconds.... I called my dad to see what if anything he could think of to at least get me back home....I eventually called a towtruck and after about 45 minutes from the original problem I got it to start and drove it home. I then drove it over to my dad's the next day and no real problems...didn't feel 100% but it made it.
So now it's got the front end torn apart...replaced spark plugs which were dirty, found a broken clip on the opti-spark wiring harness with some dirt on it but no corrosion. one guy says the waterpump has been replaced prior...the radiator fluid was low but not real low...at least a gallon and a half I think...radiator fluid level sensor was unplugged...I have watched the temperature gauge ever since I got the car and it always tops out around the middle...I think thats 200 from memory? it starts out at 160...car has never overheated while I have owned it. It's currently got 80,000 miles on it. I bought it used out of texas with about 60,000 on it.
Also replaced the spark plug wires, ignition coil, fuel filter, water pump and serpentine belt..even master cylinder & brakes... fuel filter was dirty not sure how dirty?
I have been kind of just having them replace low cost items just because if they have to do with the fuel system because of the two times I ran out...heard that can suck dirt from the bottom of the gas tank....haven't fired it up because we're still waiting on the radiator hoses LARGE ones...as they were soft...
one more thing is I have a wings west ground effects kit which requires a larger air dam...it hangs about 3 inches lower...it broke last summer but only had a crack in the middle section. I replaced this as well...haven't really driven it on any drives over 50 miles since the last time it ran out of gas.
I realize I may have multiple problems here but I figured by putting all the little things on here it would help clue you guys in on possible solutions. Thanks in advance for any help!!!
Now I have been driving it since march and I noticed some hesitation/surging building upon heavy acceleration... I lined up at a light by some guy we both floored it...I accelerated smoothly up to about 60mph where it seemed to almost die...then whiplash it surged...I have watched it and the rpms are going to the redline when this happens... I decided to change the oil and clean my k&n air filter and found the k&n was very dirty and had actually fallen off.... I cleaned it very amateurishly figuring it would take it over to some guy my dad knows to get it checked out in the next few days... I let it dry over a day...and drove it about 2 miles each way one day no problem...the next day I drove to the exact same place but this time upon pulling out of the parking spot I got straightened out and then the car stalled...I restarted and it stalled....I did this repeately...it wouldn't start but I am almost 100% sure it's not the starter, I've replaced them before on other cars and heard clicking, one time it made a funny noise like a misfire and died out after running real rough for a few seconds.... I called my dad to see what if anything he could think of to at least get me back home....I eventually called a towtruck and after about 45 minutes from the original problem I got it to start and drove it home. I then drove it over to my dad's the next day and no real problems...didn't feel 100% but it made it.
So now it's got the front end torn apart...replaced spark plugs which were dirty, found a broken clip on the opti-spark wiring harness with some dirt on it but no corrosion. one guy says the waterpump has been replaced prior...the radiator fluid was low but not real low...at least a gallon and a half I think...radiator fluid level sensor was unplugged...I have watched the temperature gauge ever since I got the car and it always tops out around the middle...I think thats 200 from memory? it starts out at 160...car has never overheated while I have owned it. It's currently got 80,000 miles on it. I bought it used out of texas with about 60,000 on it.
Also replaced the spark plug wires, ignition coil, fuel filter, water pump and serpentine belt..even master cylinder & brakes... fuel filter was dirty not sure how dirty?
I have been kind of just having them replace low cost items just because if they have to do with the fuel system because of the two times I ran out...heard that can suck dirt from the bottom of the gas tank....haven't fired it up because we're still waiting on the radiator hoses LARGE ones...as they were soft...
one more thing is I have a wings west ground effects kit which requires a larger air dam...it hangs about 3 inches lower...it broke last summer but only had a crack in the middle section. I replaced this as well...haven't really driven it on any drives over 50 miles since the last time it ran out of gas.
I realize I may have multiple problems here but I figured by putting all the little things on here it would help clue you guys in on possible solutions. Thanks in advance for any help!!!
Last edited by eanhl2004; 05-18-2009 at 04:15 PM.
05-17-2009, 10:22 AM
#2
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Location: Hell was full so they sent me to NJ
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You would probably get the best results by posting each topic in the correct forum.
Do you mean the shifter does not sty fixed in the position you set it in? Can we assume this is an automatic? This would get best results in the "Drivetrain" forum
There is a charcoal cansiter in the driver's side rear fender. It collects fuel vapor venting from the gas tank, then uses engine vacuum to feed the fuel vapor to the engine. The fuel smell may be from the canister being saturated with fuel, or the hoses, which are sandwiched between the tank and the body, and impossible to access may be rotted out. Could also be due to the EVAP purge system, activated by a solenoid, on a bracket on the passenger side of the intake manifold, is not working, or the solenod or lines may be plugged with carbon particles.
The fuel gauges are always misleading. From the factory, mine would show above "F" with the tank full, and stay there for the first 75 miles or so. Then would gradually drop, until it was at "1/2" and had only about 5 gallons left. Then it would drop like a rock to "1/4", at which point it only had 1 or 2 gallons left.
Are you saying that the car stop pulling forward hard, and the tach heads for the red? Sounds like the tranny is slipping. Figure out whether is misfiring and bogging (LT1 Based Engine Tech forum), or whether the tranny is slipping (Drivetrain forum)
How did you clean the K&N? You have to clean it with soapy water, and let it dry. Then LIGHTLY oil it with the reocmmended K&N oil. If you don't oil it, it doesn't filter. If you over-oil it, it contaminates the MAF sensor and screws things up, producing problems like you are having. The K&N actually works better with a light coating of dust on it. K&N recommend cleaning intervals of 25-50,000 miles. Post on LT1 Based Engine Tech forum.
What do you mean by "wouldn't start"? Do you mean the starter would not turn, the starter would not engage, the starter engaged but the engine wouldn't start? (LT1 Based Engine Tech)
(LT1 Based Engine Tech)
The LT1's "reverse flow" cooling system can not have any air in it, or it will not cool correctly. The system has to be completely full, and the air needs to be bled out of it using the two bleeder screws, one on the t'stat housing, and one on the heater hose. Shoebox has a procedure (this is a great site for LT1 info):
http://shbox.com/1/4th_gen_tech1.html
http://shbox.com/1/4th_gen_tech2.html#radflush
People will unplug the radiator coolant level switch to prevent the "low coolant" idiot light on the dash from coming on. The sensors aren't very good, and fill up with crud and stop working after a while. You can try cleaning it - might help.
The middle of the coolant temp gauge is 210*F. Stock fan "on" tempeeratures in the PCM are 226*F for the low speed, and 235*F for the high speed. GM intended for the engine to run with the gauge in the middle, mostly for low emissions and better fuel mileage.
The fuel pump doesn't stop working because of picking up dirt from the bottom of the tank. It fails because it uses the fuel to keep the pump cool, and when you run out of fuel it overheats.
runs fine for another 2 years....last summer I ran out of GAS...then went up north and had about 3/4 of a tank or less in it according to the gauge?...ran out of gas...you could literally watch the gauge drop....have watched it constantly since and it seems to stay at full/overfull to 3/4 for 50+ miles and then rapidly drops from 3/4 to nothing? I did awhile ago smell gas by the rear driver's side tire and looked under the vehicle for any signs of leaking gas..nothing on the ground or the tank...
The fuel gauges are always misleading. From the factory, mine would show above "F" with the tank full, and stay there for the first 75 miles or so. Then would gradually drop, until it was at "1/2" and had only about 5 gallons left. Then it would drop like a rock to "1/4", at which point it only had 1 or 2 gallons left.
Now I have been driving it since march and I noticed some hesitation/surging building upon heavy acceleration... I lined up at a light by some guy we both floored it...I accelerated smoothly up to about 60mph where it seemed to almost die...then whiplash it surged...I have watched it and the rpms are going to the redline when this happens...
I decided to change the oil and clean my k&n air filter and found the k&n was very dirty and had actually fallen off.... I cleaned it very amateurishly figuring it would take it over to some guy my dad knows to get it checked out in the next few days... I let it dry over a day...and drove it about 2 miles each way one day no problem...the next day I drove to the exact same place but this time upon pulling out of the parking spot I got straightened out and then the car stalled...I restarted and it stalled....
I did this repeately...it wouldn't start but I am almost 100% sure it's not the starter, I've replaced them before on other cars and heard clicking, one time it made a funny noise like a misfire and died out after running real rough for a few seconds.... I called my dad to see what if anything he could think of to at least get me back home....I eventually called a towtruck and after about 45 minutes from the original problem I got it to start and drove it home. I then drove it over to my dad's the next day and no real problems...didn't feel 100% but it made it.
So now it's got the front end torn apart...replaced spark plugs which were dirty, found a broken clip on the opti-spark wiring harness with some dirt on it but no corrosion. one guy says the waterpump has been replaced prior...the radiator fluid was low but not real low...at least a gallon and a half I think...radiator fluid level sensor was unplugged...I have watched the temperature gauge ever since I got the car and it always tops out around the middle...I think thats 200 from memory? it starts out at 160...car has never overheated while I have owned it. It's currently got 80,000 miles on it. I bought it used out of texas with about 60,000 on it.
The LT1's "reverse flow" cooling system can not have any air in it, or it will not cool correctly. The system has to be completely full, and the air needs to be bled out of it using the two bleeder screws, one on the t'stat housing, and one on the heater hose. Shoebox has a procedure (this is a great site for LT1 info):
http://shbox.com/1/4th_gen_tech1.html
http://shbox.com/1/4th_gen_tech2.html#radflush
People will unplug the radiator coolant level switch to prevent the "low coolant" idiot light on the dash from coming on. The sensors aren't very good, and fill up with crud and stop working after a while. You can try cleaning it - might help.
The middle of the coolant temp gauge is 210*F. Stock fan "on" tempeeratures in the PCM are 226*F for the low speed, and 235*F for the high speed. GM intended for the engine to run with the gauge in the middle, mostly for low emissions and better fuel mileage.
I have been kind of just having them replace low cost items just because if they have to do with the fuel system because of the two times I ran out...heard that can suck dirt from the bottom of the gas tank....haven't fired it up because we're still waiting on the radiator hoses LARGE ones...as they were soft...
05-17-2009, 06:00 PM
#3
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Thread Starter
Join Date: May 2009
Posts: 95
There is a charcoal cansiter in the driver's side rear fender. It collects fuel vapor venting from the gas tank, then uses engine vacuum to feed the fuel vapor to the engine. The fuel smell may be from the canister being saturated with fuel, or the hoses, which are sandwiched between the tank and the body, and impossible to access may be rotted out. Could also be due to the EVAP purge system, activated by a solenoid, on a bracket on the passenger side of the intake manifold, is not working, or the solenod or lines may be plugged with carbon particles.
The fuel gauges are always misleading. From the factory, mine would show above "F" with the tank full, and stay there for the first 75 miles or so. Then would gradually drop, until it was at "1/2" and had only about 5 gallons left. Then it would drop like a rock to "1/4", at which point it only had 1 or 2 gallons left.
The fuel gauges are always misleading. From the factory, mine would show above "F" with the tank full, and stay there for the first 75 miles or so. Then would gradually drop, until it was at "1/2" and had only about 5 gallons left. Then it would drop like a rock to "1/4", at which point it only had 1 or 2 gallons left.
How did you clean the K&N? You have to clean it with soapy water, and let it dry. Then LIGHTLY oil it with the reocmmended K&N oil. If you don't oil it, it doesn't filter. If you over-oil it, it contaminates the MAF sensor and screws things up, producing problems like you are having. The K&N actually works better with a light coating of dust on it. K&N recommend cleaning intervals of 25-50,000 miles. Post on LT1 Based Engine Tech forum.
The LT1's "reverse flow" cooling system can not have any air in it, or it will not cool correctly. The system has to be completely full, and the air needs to be bled out of it using the two bleeder screws, one on the t'stat housing, and one on the heater hose. Shoebox has a procedure (this is a great site for LT1 info):
http://shbox.com/1/4th_gen_tech1.html
http://shbox.com/1/4th_gen_tech2.html#radflush
People will unplug the radiator coolant level switch to prevent the "low coolant" idiot light on the dash from coming on. The sensors aren't very good, and fill up with crud and stop working after a while. You can try cleaning it - might help.
The middle of the coolant temp gauge is 210*F. Stock fan "on" tempeeratures in the PCM are 226*F for the low speed, and 235*F for the high speed. GM intended for the engine to run with the gauge in the middle, mostly for low emissions and better fuel mileage.
http://shbox.com/1/4th_gen_tech1.html
http://shbox.com/1/4th_gen_tech2.html#radflush
People will unplug the radiator coolant level switch to prevent the "low coolant" idiot light on the dash from coming on. The sensors aren't very good, and fill up with crud and stop working after a while. You can try cleaning it - might help.
The middle of the coolant temp gauge is 210*F. Stock fan "on" tempeeratures in the PCM are 226*F for the low speed, and 235*F for the high speed. GM intended for the engine to run with the gauge in the middle, mostly for low emissions and better fuel mileage.
My dad said the radiator fluid was low but I didn't see it for myself prior and the pan they had looked like 1-1/2 gallons of fluid at least. Water pump I was told has been worked on...wasn't on right..or one screw was loose? I don't get how the gauge can work and the temps range from 160 (cold) to over 200 (hot) but never close to RED?
I posted all the info in this forum due to the multiple threads on hesitation and optispark... My main concern is the stalling and not restarting....it's definately not the starter imo because it's starting (no cranking sound) but instead of the engine running it just dies out....same thing happens with the lawn mower and then I remove the spark plugs to find them black....replace with new and runs like a champ...
After I get the radiator hoses back on I will make sure to bleed the air from the cooling system...then I plan to check the ohms to make sure the fuel injectors are good...I'm hoping it runs and doesn't hesitate after this....the air filter is completely cleaned properly....oiled as well...the mass air filter screen was dirty but I was told it's still good and it's clean now...as is the sensor....
If the tranny was slipping wouldn't it do it more consistently..than say once out 100 shifts? automatic shifts... and yes the car seems to slow it's acceleration when the tach heads for red...when accelerating smoothly it's below the red.... the air filter and plugs were both dirty so I haven't let my mind go to a tranny problem as of yet....
I guess I am wondering what to do next? my problems may be solved already when I get it back together now....but if not then I will post a problem in the tranny section...
one more thing...I read in some post on the opti-spark that maybe some codes are sent to the computer but not a service engine soon light....is this true and can I get the free autozone check to pull these codes up if it is true... I am thinking of checking the optispark/rotor/cap? whatever this vehicle has to eliminate them before moving to the tranny.... if autozone doesn't work what is a good OBD II scanner? or should I pay a dealer which I don't trust? I don't trust any dealers....except for buying a brand new car only...lol
once again sorry for the rambling and somethings being in the wrong spot...just thinking maybe some problems that seem to be tranny related are not the tranny at all
thanks for your response/help
Last edited by eanhl2004; 05-18-2009 at 05:06 AM.
05-18-2009, 03:46 PM
#4
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Join Date: May 2009
Posts: 95
UPDATE:
Just got the car back..
New thermostat 195 degree installed
New Air Dam for Ground Effects installed
plus all work mentioned in posts above
Took car immediately over to Autozone for free diagnostic OBD Scan
Code P0100 MAF VAF popped up...
Still seems sluggish at times, especially when not punching on the accelerator...varied performance...As I mentioned above the air filter fell off at some point and the MAF screen was dirty but cleaned everything and replaced. What should I do now? Will resetting the code/deleting do anything... I'm assuming that it would only clear it so when it performs like crap again the code will repeat? (No MIL, SES lights)
Should I replace it and not bother deleting the code and waiting for it to repeat?
How many of the problems I stated before are related to the MAF?
Such as fuel economy, poor acceleration/hesitation/surge/stalling?
If I do have to get a new MAF should I spend $180 for a REMAN or $300 for a new? Should I go performance/aftermarket MAF...? (I have K&N air filter system)
Thanks for any help!!!
Just got the car back..
New thermostat 195 degree installed
New Air Dam for Ground Effects installed
plus all work mentioned in posts above
Took car immediately over to Autozone for free diagnostic OBD Scan
Code P0100 MAF VAF popped up...
Still seems sluggish at times, especially when not punching on the accelerator...varied performance...As I mentioned above the air filter fell off at some point and the MAF screen was dirty but cleaned everything and replaced. What should I do now? Will resetting the code/deleting do anything... I'm assuming that it would only clear it so when it performs like crap again the code will repeat? (No MIL, SES lights)
Should I replace it and not bother deleting the code and waiting for it to repeat?
How many of the problems I stated before are related to the MAF?
Such as fuel economy, poor acceleration/hesitation/surge/stalling?
If I do have to get a new MAF should I spend $180 for a REMAN or $300 for a new? Should I go performance/aftermarket MAF...? (I have K&N air filter system)
Thanks for any help!!!
05-18-2009, 11:53 PM
#5
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,676
Wrong temperature 'stat. Stock is 180*F. You do not want to go higher than that with the LT1's "reverse flow" cooling system. Hopefully they used the correct 'stat for the LT1. It is not the same as the Gen 1 SBC 'stat that many parts shops sell you because they don't know any better.
Common problem on the 97's. Pull the MAF harness connector off, and check for 12V between the pink wire and the black/white wire in the harness. For some reason, the 97 wiring harness frequently suffers from a break in the pink wire somewhere deep in the harness.
Clearing the code won't do anything. If the problem is still there, as soon as the engine reaches the operating conditions that the PCM looks for to run the diagnostic, the code will return. Its not running bad because the code is set. Its running bad because of the problem causing the code.
Before replacing it, check the wiring. Also check the pins in the harness connector and in the MAF sensor. If you can, borrow a known "good" MAF sensor and see if it eliminates the code. P0100 indicates the MAF circuit frequency signal is not responding to changes in the engine that should change the air flow. When the code sets, the PCM will default to speed-density mode. Now your MAP sensor and inlet air temperature sensors become extremely critical. Speed-density also relies on an internal program table of volumetric efficiency. If you've made any modifications that affect the breathing of the engine (intake or exhaust), the VE tables may not be accurate any more, possibly accounting for erratic engine operation.
Have you also checked the rubber inlet elbow for tears, or the bottom of it not being on the throttle body?
Buy an AC/Delco part (now sold as "Delphi"). GM recently changed the replacement LT1 MAF to the same part # as the LS1 MAF sensor, and lowered the price. Source for discount GM parts shown on Shoebox's site:
http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason
Code P0100 MAF VAF popped up...
Still seems sluggish at times, especially when not punching on the accelerator...varied performance...As I mentioned above the air filter fell off at some point and the MAF screen was dirty but cleaned everything and replaced. What should I do now? Will resetting the code/deleting do anything... I'm assuming that it would only clear it so when it performs like crap again the code will repeat? (No MIL, SES lights)
Should I replace it and not bother deleting the code and waiting for it to repeat?
How many of the problems I stated before are related to the MAF?
How many of the problems I stated before are related to the MAF?
Have you also checked the rubber inlet elbow for tears, or the bottom of it not being on the throttle body?
If I do have to get a new MAF should I spend $180 for a REMAN or $300 for a new? Should I go performance/aftermarket MAF...? (I have K&N air filter system)
http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason
05-20-2009, 03:45 PM
#6
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Thread Starter
Join Date: May 2009
Posts: 95
I checked the Volts on the MAF wiring harness...pink to black is 11.07
That is good right? I mean it's not 12v but close enough I believe...any other thing to test prior to a new maf?
I got a OBDII scanner and it showed the code, I deleted it and then drove the z28 and it hesitates at slow speed as well...I drove it fast (not slammed) up to 70mph down the street since it seems to really hesitate surge at 60-65mph and rescanned when I got home...nothing...
I can try a scan again everyday now!
no reason not too
I am thinking the MAF failure was probably due to a fluke during the massive front end changes to the new parts mentioned above...and maf probably not tied to the hesitation surge, sound about right?
That is good right? I mean it's not 12v but close enough I believe...any other thing to test prior to a new maf?
I got a OBDII scanner and it showed the code, I deleted it and then drove the z28 and it hesitates at slow speed as well...I drove it fast (not slammed) up to 70mph down the street since it seems to really hesitate surge at 60-65mph and rescanned when I got home...nothing...
I can try a scan again everyday now!
no reason not tooI am thinking the MAF failure was probably due to a fluke during the massive front end changes to the new parts mentioned above...and maf probably not tied to the hesitation surge, sound about right?
Last edited by eanhl2004; 05-20-2009 at 04:30 PM.
05-23-2009, 08:56 PM
#7
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Join Date: May 2009
Posts: 95
I have tried unsuccessfully to get the MAF code P0100 to show up which I am now believing is FIXED. I found a dirty/broken Opti-spark wiring harness which I cleaned and replaced temporarily as dealers wanted $200+ for a replacement. I went ahead and ordered one from eficonnection.com as suggested for $32.50 shipped. Received in the mail today and placed onto the car. I heard the clip click as in compliance with GM's PCP protocol (Push-Click-Pull). Started the car and then turned off and checked for DTC codes....nothing...Took it out for a spin...noticed the start time was about half of what it was prior. Still getting very slight hesitation though.
Here is the old and new opti-spark wiring harness bad connection
I figured I was better off with a new one with a clip for $35 than leaving the old one on there.
I did find some more possible problems/solutions to these issues I am having.
I have 2 hoses on top of the engine which are rubber rotting/cracking. I need help with what these hoses are connected to and/or what they do?
Here are some pics which I labeled with #1 and #2 since they are both connected to different things. I plan on replacing these as well if I can figure out what they are to order them.
Picture was taken from the passenger side fender. I don't see any signs off fluids which leads me to believe once again it's an air/vacuum issue...? But I have no clue. They may be fluids but the hoses are barely good enough and about to fall apart!!!!
Here is the old and new opti-spark wiring harness bad connection
I figured I was better off with a new one with a clip for $35 than leaving the old one on there.
I did find some more possible problems/solutions to these issues I am having.
I have 2 hoses on top of the engine which are rubber rotting/cracking. I need help with what these hoses are connected to and/or what they do?
Here are some pics which I labeled with #1 and #2 since they are both connected to different things. I plan on replacing these as well if I can figure out what they are to order them.
Picture was taken from the passenger side fender. I don't see any signs off fluids which leads me to believe once again it's an air/vacuum issue...? But I have no clue. They may be fluids but the hoses are barely good enough and about to fall apart!!!!
05-23-2009, 11:09 PM
#8
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,676
The hoses appear to be part of the EVAP purge system.
There is a charcoal canister in the driver's rear fender, that absorbs fuel vapor venting from the fuel tank (emissions control). There is a "3rd line" in the fuel line bundle that allows engine vacuum to pull air through the charcoal canister (purge it) to desorb the fuel vapors, and pull them into the engine to be burned. The purge is activated by a solenoid on the bracket on the passenger side of the intake manifold, same one that the Opti harness connector is supported on. On the 96/97 OBD-II cars, there is a vacuum switch in the line coming from the tank, to detect faulty system operation. Then the line from the tank connects to the solenoid, and there is a line from the solenoid to the passenger side of the throttle body.
All the system components are shown in this diagram (courtesty of Shoebox):
http://shbox.com/1/1996_evap.jpg
There is a charcoal canister in the driver's rear fender, that absorbs fuel vapor venting from the fuel tank (emissions control). There is a "3rd line" in the fuel line bundle that allows engine vacuum to pull air through the charcoal canister (purge it) to desorb the fuel vapors, and pull them into the engine to be burned. The purge is activated by a solenoid on the bracket on the passenger side of the intake manifold, same one that the Opti harness connector is supported on. On the 96/97 OBD-II cars, there is a vacuum switch in the line coming from the tank, to detect faulty system operation. Then the line from the tank connects to the solenoid, and there is a line from the solenoid to the passenger side of the throttle body.
All the system components are shown in this diagram (courtesty of Shoebox):
http://shbox.com/1/1996_evap.jpg
05-24-2009, 01:49 AM
#9
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Thread Starter
Join Date: May 2009
Posts: 95
Your info definately gave me the path to finding the parts...
Rob needs to fix that image so the #'s relating to the diagram are listed in a key somewhere. If I can figure all of them out I will edit it and email it to him and maybe save someone some time
found both part names
10105324 - Evaporator Solenoid Pipe Assembly (#1 on my pictures)
12556259 - S Vacuum Hose (#2 on my pictures)
Rob needs to fix that image so the #'s relating to the diagram are listed in a key somewhere. If I can figure all of them out I will edit it and email it to him and maybe save someone some time
found both part names
10105324 - Evaporator Solenoid Pipe Assembly (#1 on my pictures)
12556259 - S Vacuum Hose (#2 on my pictures)
05-24-2009, 09:46 AM
#10
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,676
I think people expect far too much from Rob. He's provided a treaure trove of information, but its still not enough to satisfy some people. Sometimes we have to do a little bit of the research ourselves.
05-24-2009, 04:10 PM
#11
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Join Date: May 2009
Posts: 95
Don't get me wrong I'm not trying to bash rob at all, I'm a bit of a PERFECTIONIST, which should explain it all....
I appreciate any and all HELP! I will try and get this done for him just to make his site/help even better. Especially since you never know when I may need it again and I'd rather only look up the info once...
So whenever I give any criticism or something like this I am only trying to make this site and rob's site BETTER!... So once again thank you Injuneer and Rob because both of these sites have saved me some $ and solved some problems!!!
A REAL bonus when your unemployed and having car problems in MICHIGAN where Jobs are few!
I appreciate any and all HELP! I will try and get this done for him just to make his site/help even better. Especially since you never know when I may need it again and I'd rather only look up the info once...
So whenever I give any criticism or something like this I am only trying to make this site and rob's site BETTER!... So once again thank you Injuneer and Rob because both of these sites have saved me some $ and solved some problems!!!
A REAL bonus when your unemployed and having car problems in MICHIGAN where Jobs are few!
06-01-2009, 11:40 PM
#12
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Thread Starter
Join Date: May 2009
Posts: 95
Okay I finally got the two hoses and replaced them.
10105324 - Evaporator Solenoid Pipe Assembly was really bad connection and probably a very significant leak. The other hose seem to be purely visual, seems like it's okay just looked bad, switched it anyway. Now the car seems to hesitate/surge more and it only seems to do it noticeably at grandma acceleration...it does it really bad at around 10mph feels like it will stall if you don't give it some gas. I went and picked up a Fuel Pressure Gauge and Multimeter (10megohm auto-ranging) and plan on testing the fuel pressure and injectors next...was hoping my bad hoses were the direct cause of the problems but no such luck. The guy at the parts store said sometimes it's the EGR Valve for stall/surge/hesitation...so I did some research and found a finger test. Idle the car and push on the bottom (valves) of the EGR VALVE while in idle and if it stalls the EGR VALVE is working, I was specifically told to use two fingers, one on each side of the bottom...I tried one finger first and got it close to stall and then with noth fingers and some effort it did stall. I was planning on taking the egr valve off to clean/inspect it but there is no room for my 6" wrench nor enough for a socket wrench? I also pushed on the EGR VALVE without the car running prior to all this and it sounded like a fuel primer does on a lawn mower...spungy feel and like there was liquid. Is this normal? Is there some kind of tool I can buy to make it easy to get these two nuts off the EGR VALVE....lots of wires/crap in the way and it's right under the front windshield/panel I believe the nuts 1/2 inch.
It hasn't stalled again, I also haven't floored it from a dead stop in awhile so I don't know if it would surge badly again at WOT and about 65mph. Been OBDII scanning it daily and nothing. If I can figure out how to remove this EGR Valve tool-wise/room-wise I think I can switch it for $50 which should eliminate the possibility it's going bad...
Regardless I am learning a ton but REGRETFULLY it's on a 97 camaro which is a pain room-wise.... LOL
Can I unplug the vacuum on top of the egr valve and drive down the road to see if the hesitation/surge stops? I read this for some other vehicle...as a cheap way to find out if your egr valve is going bad? I went ahead and unplugged the vacuum at the top of the egr valve at the store about 1-2miles away and drove it home....seems better still some issues which are likely tranny issues, more like delay but not any sign of surge/hesitation...I am not concerned with figuring out any tranny issues right now....only the hesitation/surge and stall/no start...I now believe that if I can't start my car one thing to try is unplugging the egr valve vacuum, sound right? I mean if it's a egr problem it only happens at start-up and low speed acceleration NOT WOT -wide open throttle- so assuming my egr is going bad..probably some rubber breaking as that is the case with other rubber in this car and it was a TEXAS car originally which is more prone to rubber rot than rust as is the case here in michigan.???any confirmation on this egr stuff?
10105324 - Evaporator Solenoid Pipe Assembly was really bad connection and probably a very significant leak. The other hose seem to be purely visual, seems like it's okay just looked bad, switched it anyway. Now the car seems to hesitate/surge more and it only seems to do it noticeably at grandma acceleration...it does it really bad at around 10mph feels like it will stall if you don't give it some gas. I went and picked up a Fuel Pressure Gauge and Multimeter (10megohm auto-ranging) and plan on testing the fuel pressure and injectors next...was hoping my bad hoses were the direct cause of the problems but no such luck. The guy at the parts store said sometimes it's the EGR Valve for stall/surge/hesitation...so I did some research and found a finger test. Idle the car and push on the bottom (valves) of the EGR VALVE while in idle and if it stalls the EGR VALVE is working, I was specifically told to use two fingers, one on each side of the bottom...I tried one finger first and got it close to stall and then with noth fingers and some effort it did stall. I was planning on taking the egr valve off to clean/inspect it but there is no room for my 6" wrench nor enough for a socket wrench? I also pushed on the EGR VALVE without the car running prior to all this and it sounded like a fuel primer does on a lawn mower...spungy feel and like there was liquid. Is this normal? Is there some kind of tool I can buy to make it easy to get these two nuts off the EGR VALVE....lots of wires/crap in the way and it's right under the front windshield/panel I believe the nuts 1/2 inch.
It hasn't stalled again, I also haven't floored it from a dead stop in awhile so I don't know if it would surge badly again at WOT and about 65mph. Been OBDII scanning it daily and nothing. If I can figure out how to remove this EGR Valve tool-wise/room-wise I think I can switch it for $50 which should eliminate the possibility it's going bad...
Regardless I am learning a ton but REGRETFULLY it's on a 97 camaro which is a pain room-wise.... LOL
Can I unplug the vacuum on top of the egr valve and drive down the road to see if the hesitation/surge stops? I read this for some other vehicle...as a cheap way to find out if your egr valve is going bad? I went ahead and unplugged the vacuum at the top of the egr valve at the store about 1-2miles away and drove it home....seems better still some issues which are likely tranny issues, more like delay but not any sign of surge/hesitation...I am not concerned with figuring out any tranny issues right now....only the hesitation/surge and stall/no start...I now believe that if I can't start my car one thing to try is unplugging the egr valve vacuum, sound right? I mean if it's a egr problem it only happens at start-up and low speed acceleration NOT WOT -wide open throttle- so assuming my egr is going bad..probably some rubber breaking as that is the case with other rubber in this car and it was a TEXAS car originally which is more prone to rubber rot than rust as is the case here in michigan.???any confirmation on this egr stuff?
Last edited by eanhl2004; 06-02-2009 at 01:20 AM.
06-02-2009, 05:30 AM
#13
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,676
The EGR system does not operate at startup, at idle or at WOT. It generally opens only when the engine is operating in the 1000-3500rpm range, at moderate loads, often at lower RPM when lugging the engine in the wrong gear. Your finger test shows that the valve is closing correctly, so it should not prove to be a problem under most conditions. If it is opening, and IF the poor operating conditions can be correlated to the valve opening, perhaps something in the system is leaking air into the system, rather than exhaust gas. Check the riser tube from the #8 exhaust primary to the back of the intake manifold. Maybe the tube is cracked or loose.
06-02-2009, 10:15 AM
#14
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Join Date: May 2009
Posts: 95
Well the 1000 - 3,500 rpm makes sense for the hesitation/surge. I drove it some more just now....both vacuum on and off the EGR VALVE, it's hesitating both ways but seems more like tranny delay with the vac OFF, with the vac on the egr it goes right back to the barely noticable hesitation/surge pretty much all the time unless your flooring the gas...
#8 exhaust is this the cylinder #8? I'm sorry I'm far from a mechanic LOL...
you just went over my head again... I have the service manual but can't find the section for egr testing/troubleshooting for a v8. I did check once again visually as much as I can see all around the top of the engine...found a 1" dia. hose from the throttle body passenger side to the valve cover...it was almost sitting on top rather than "IN" the valve cover....don't know if this was the case prior to all the recent work or not...also near the driver's side egr valve there was a sort of rubber nut/cap on some line for the fuel in.out lines from the regulator...top line? it sort of seals the end! I put it on correctly... I also noticed a slight dent in a silver tubing on the passenger side no sign of any hole or leak, it's 1/4" dia. silver with rubber grommet connecting near/below the throttle body and running to the back of the engine somewhere? it doesn't look like it's enough of a ding to harm anything but not sure yet...not sure what it is either...I will try to find out!!!
ADD: I tried the vac to egr ON again...fairly hard acceleration...ok...then stopped at light and turned with slow accel. HORRIBLE surge/hesitation...feels like it's going to die... pulled the vac off egr once again and problem seems to dissappear... I am no mechanic but I am 99% sure the vacuum and/or EGR system...the valve probably/possibly is ok since it stalls with the two thumbs test...but the vacuum line off seems to cure the car....??? I also know for sure the nuts on the egr are 1/2" but the driver's side won't come off... it's possible stripped or maybe even was replaced at some point...nothing fits correctly...11mm 12mm 13mm 1/2 9/16 etc.... 1/2" open end wrench seems to fit but then slips when you think its turning... I had it out in the sunlight and a 500watt halogen spot on it so I see it clear as possible...makes me think there was a prior problem...the closed ended wrench with easier nut gripping don't work either... I was really hoping to pull it off to inspect it since the vac line off it seems to cure the problem.... I would like to know what the exhaust #8 thing is I checked visually almost all vac lines...(1/8 black tubings & rubber fittings) no visual or loose ends...may be leaks somewhere though...
This is so annoying, if the EGR is disco's the car works so why the heck is it on there? LMAO
Can you please aid my ignorance by desrcribing the "Check the riser tube from the #8 exhaust primary to the back of the intake manifold. Maybe the tube is cracked or loose." a little more.... the intake manifold is under the fuel injector/rail and above the engine is the riser tube on the front/back/drivers/passenger side? of the engine...is it a black tube? about how much diameter? any kind of description would help alot... I can't find it on shbox and the service manual is not helping...no way to locate anything unless you know the 5 different names for it and it's purpose....not for a rookie in most cases...
#8 exhaust is this the cylinder #8? I'm sorry I'm far from a mechanic LOL...
you just went over my head again... I have the service manual but can't find the section for egr testing/troubleshooting for a v8. I did check once again visually as much as I can see all around the top of the engine...found a 1" dia. hose from the throttle body passenger side to the valve cover...it was almost sitting on top rather than "IN" the valve cover....don't know if this was the case prior to all the recent work or not...also near the driver's side egr valve there was a sort of rubber nut/cap on some line for the fuel in.out lines from the regulator...top line? it sort of seals the end! I put it on correctly... I also noticed a slight dent in a silver tubing on the passenger side no sign of any hole or leak, it's 1/4" dia. silver with rubber grommet connecting near/below the throttle body and running to the back of the engine somewhere? it doesn't look like it's enough of a ding to harm anything but not sure yet...not sure what it is either...I will try to find out!!!
ADD: I tried the vac to egr ON again...fairly hard acceleration...ok...then stopped at light and turned with slow accel. HORRIBLE surge/hesitation...feels like it's going to die... pulled the vac off egr once again and problem seems to dissappear... I am no mechanic but I am 99% sure the vacuum and/or EGR system...the valve probably/possibly is ok since it stalls with the two thumbs test...but the vacuum line off seems to cure the car....??? I also know for sure the nuts on the egr are 1/2" but the driver's side won't come off... it's possible stripped or maybe even was replaced at some point...nothing fits correctly...11mm 12mm 13mm 1/2 9/16 etc.... 1/2" open end wrench seems to fit but then slips when you think its turning... I had it out in the sunlight and a 500watt halogen spot on it so I see it clear as possible...makes me think there was a prior problem...the closed ended wrench with easier nut gripping don't work either... I was really hoping to pull it off to inspect it since the vac line off it seems to cure the problem.... I would like to know what the exhaust #8 thing is I checked visually almost all vac lines...(1/8 black tubings & rubber fittings) no visual or loose ends...may be leaks somewhere though...
This is so annoying, if the EGR is disco's the car works so why the heck is it on there? LMAO
Can you please aid my ignorance by desrcribing the "Check the riser tube from the #8 exhaust primary to the back of the intake manifold. Maybe the tube is cracked or loose." a little more.... the intake manifold is under the fuel injector/rail and above the engine is the riser tube on the front/back/drivers/passenger side? of the engine...is it a black tube? about how much diameter? any kind of description would help alot... I can't find it on shbox and the service manual is not helping...no way to locate anything unless you know the 5 different names for it and it's purpose....not for a rookie in most cases...
Last edited by eanhl2004; 06-03-2009 at 04:29 PM.
06-04-2009, 02:39 AM
#15
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Thread Starter
Join Date: May 2009
Posts: 95
I may have this figured out or I may be destroying my own stuff... the egr valve nut driver's side is crap/stripped....I removed the harness and solenoid
http://shbox.com/1/EGR_solenoid.jpg to make it easier to get at the egr nut...it's stripped... but I found the vac hose to the engine/intake longer hose #4 on the diagram is broke in two spots...I may have done it myself, maybe not....part # 10105323...is this hose going from the egr to the intake...is this the exhaust hose?
going to take the car to the shop tomorrow see if they can remove the egr/stripped/nut....
probably order a new egr and hose/harness.... maybe temporarily find some hose to rig it for now
http://shbox.com/1/EGR_solenoid.jpg to make it easier to get at the egr nut...it's stripped... but I found the vac hose to the engine/intake longer hose #4 on the diagram is broke in two spots...I may have done it myself, maybe not....part # 10105323...is this hose going from the egr to the intake...is this the exhaust hose?
going to take the car to the shop tomorrow see if they can remove the egr/stripped/nut....
probably order a new egr and hose/harness.... maybe temporarily find some hose to rig it for now