hey im new to the site.....first i wanna say that i bought my first lt1 camaro and i love the lt1 mtor. my question is my car ses light is on so i went to the autozone to have it checked and there scan tool cant get no power from my aldl connection so i cant get the codes or anything. i wass reading on a other post the aldl connection part and in the cig lighter is on the same power i have no fuse in it so does that got a play is the no pwer to the connection? my car is a 96 z wit 97,xxx miles. But btw my car got a miss 1500 and 2k sometimes and if i let off the let gas the car idle surges down to 500 and back to 800 to 1000.this only happens if the car warms up.but the car revs good got no backfire or anything, runs and drives really great the power is there just the lil miss which i think is do to needing new plugs wires but can it be major?

 

You need a good fuse in the CIGAR/ACCY circuit to power the scanner. Put the fuse in it and get it scanned. Good chance that will point you in the right direction to sorting out the misfire.

 

so now im gonna go back and have it scanned,so u think its a misfire.the car revs good no stumbling or missing revs or drive its only missin in that range.ok how about a map sensor will that cause it to do that?

 

i just got back from autozone from geting scanned these codes came up


P0300:random misfire-faulty plugs,wire,vacumm leak and something else

P0420:i dunno what that is

today i wass at the gas station and my gas cap dont his nomore can that cause it to run like that!

 

this is P0420:Three Way Catalytic Converter (TWC) system low efficiency Bank 1 can ne1 tell me what taht means?

 

P0420 indicates the after-cat O2 sensor on the driver's side is not responding the way it should with a healthy cat. It could be a faulty cat, or it could be a faulty sensor. Swap the two after-cat sensors side-to-side. If the problem stays on the driver's side its a cat problem (or remote possibility a sensor wiring problem); if the problem follows the sensor to the passenger side, its a sensor problem.

If you have access to a scanner with "GM enhanced" capabilities, you can recall the actual misfire counts from the PCM, by individual cylinder. That may help identify whether its a problem with one or two cylinders, or truely a "random" misfire.

 

so buy the 2 o2 sensors after cat ,if problem is still there replace cat or passenger side o2 as well? ok and as far as the scanner cant access 1. can the random misfire come from plugs,wire? or the opti which i hope not! Plus when i start my car in the moring its puffs a lil blk smoke out the passenger side tailpipe. is that in wit the random misfire from not burnin fuel?

 

No.... don't buy any new O2 sensors. Take the existing after-cat sensors out of the left and right sides of the exhaust, and screw them into the opposite sides of the exhaust..... swap them side-to-side.
The scanner can't access "1" what?????
Random misfires can come from virtually any part of the ignition (plugs, wires, coil ICM, corroded terminals, Opti, Opti harness), any part of the fuel system (injectors, fuel pump, fuel pressure regulator), many mechanical parts of the engine (lifter, valve adjustment, ring blowby), or bad input to the PCM from the pre-cat O2 sensors (not the aftercat sensors).

Black smoke indicates its running rich. Misfires cause the engine to run excessivley rich. A faulty coolant temp sensor can cause the engine to run rich. A faulty MAP sensor, a fault MAF......etc., etc., etc...........

 

thanks for the info on that.

what i mean by the scanner is i cant get a hold of one thats what i meant.ok now since u said something bout my map sensor the clip is broken inside the map sensor.if i unplug my maf sensor the car will not start its just turns over and its try to start but it will die is that good?

will the car run okay if i swap the sensors to different sides?

 

The after-cat sensors have NOTHING to do with how the engine runs. They are only there to help the PCM determine if the catalytic convertors are working. When I say to "swap" the sensors, that means JUST the sensors. You unplug the harness connectors, move the sensors to opposite sides, then plug the harness back in.

 

ok im gonna do that today man thankz so much for the info really
so what bout the map sensor the clip is broke when i was lookin in my haynes maunal they said my map sensor has a part in the control fuel and ignition timing so if clip is and broke inside the map sensor then that is my whole problem wit my misfire.

 

The MAP harness clip needs to be replaced. If the sensor is loose, it will affect how the engine runs, if the contacts are intermittent. You can get a "pigtail"..... a new MAP connector with short lengths of wires. See the right hand side of this table, at the top:

http://shbox.com/1/Parts.htm

 

thanks man this car been car been good now it needs some fixing lol