95 z28 camaro rich with fuel and flooding
11-09-2016, 02:47 PM
#16
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Re: 95 z28 camaro rich with fuel and flooding
Scan isn't really useful. You have to let the car warm up enough, and wait long enough for the time limit for closed loop to elapse. Then the PCM will turn off the AIR pump and will go into closed loop, where it uses the O2 sensor feedback to adjust the fuel. You only ran for 58 seconds. Normal engine run time out on the timer is 206 seconds. Basically, let the engine idle at least 4 minutes while logging it. Then if you an actually drive it, we can see how the PCM is adjusting the fuel under various driving condition. There is nothing to be gained by blipping the throttle (which you did twice) while it's operating in open loop.
Right now, at idle, the PCM is using the long term fuel trims to add 25% extra fuel. That's based on what the PCM had to do last time it operated in closed loop. But with the AIR pump running, and the PCM not being in closed loop, the O2 sensors are showing very lean, because of the air being injected into the exhaust by the AIR pump.
Was the exhaust smelling rich while you were doing the data log?
Scan log also shows:
66: A/C refrigerant pressure sensor circuit (open or shorted) - Appears your A/C system is not operating. Has it been deleted? This code indicates the pressure sensor may be unplugged or the wires shorted.
73: Pressure Control Solenoid (PCS) circuit (current error) - This is the line pressure pressure control solenoid in the transmission. Problem with high current on the circuit, compared to what is commanded. With this code set the trans is set to max line pressure and you will experience harsh shifts. Can cause premature transmission wear and damage.
Right now, at idle, the PCM is using the long term fuel trims to add 25% extra fuel. That's based on what the PCM had to do last time it operated in closed loop. But with the AIR pump running, and the PCM not being in closed loop, the O2 sensors are showing very lean, because of the air being injected into the exhaust by the AIR pump.
Was the exhaust smelling rich while you were doing the data log?
Codes it is throwing
16: Distributor ignition system (low resolution pulse) - If the engine is running, this is a "stored" code, not an active code. If it is active, indicating no low resolution pulse signal from the optical cam position sensor in the Opti, the PCM shuts down the fuel pump and the injectors. Not unusual to see this as a stored code. Clear it and see how fast it comes back.
43: Knock Sensor (KS Circuit) - Voltage on the knock sensor is not correct. This may also be a stored code, because if it was active, the PCM would be retarding timing, and there is no evidence of that in the data log. Clear it.
44: Bank 1 (Left) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated) - Have you cleared codes since you replaced the O2 sensors? What brand O2 sensors did you buy? The left side looks OK at 0.004 volts with the AIR pump running. The right side never drops below 0.133 volts, which is unusual. As mentioned, the long term fuel trims (LTFT) are adding 25% extra fuel, which would account for this code, and for the rich condition you report. Have you driven it since the O2 sensors were replaced? Bad sensors would cause the code to set, and the rich condition. Clear it.
51: EEPROM Programming error - PCM detected in internal check-sum error in the program. But there is no evidence of this in the data log. Clear it.
64: Bank 2 (Right) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated) - same comments as DTC 44.
77: Cooling fan relay control circuit - Fan #1 control circuit (from PCM to fan relay) is either open or shorted.
16: Distributor ignition system (low resolution pulse) - If the engine is running, this is a "stored" code, not an active code. If it is active, indicating no low resolution pulse signal from the optical cam position sensor in the Opti, the PCM shuts down the fuel pump and the injectors. Not unusual to see this as a stored code. Clear it and see how fast it comes back.
43: Knock Sensor (KS Circuit) - Voltage on the knock sensor is not correct. This may also be a stored code, because if it was active, the PCM would be retarding timing, and there is no evidence of that in the data log. Clear it.
44: Bank 1 (Left) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated) - Have you cleared codes since you replaced the O2 sensors? What brand O2 sensors did you buy? The left side looks OK at 0.004 volts with the AIR pump running. The right side never drops below 0.133 volts, which is unusual. As mentioned, the long term fuel trims (LTFT) are adding 25% extra fuel, which would account for this code, and for the rich condition you report. Have you driven it since the O2 sensors were replaced? Bad sensors would cause the code to set, and the rich condition. Clear it.
51: EEPROM Programming error - PCM detected in internal check-sum error in the program. But there is no evidence of this in the data log. Clear it.
64: Bank 2 (Right) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated) - same comments as DTC 44.
77: Cooling fan relay control circuit - Fan #1 control circuit (from PCM to fan relay) is either open or shorted.
66: A/C refrigerant pressure sensor circuit (open or shorted) - Appears your A/C system is not operating. Has it been deleted? This code indicates the pressure sensor may be unplugged or the wires shorted.
73: Pressure Control Solenoid (PCS) circuit (current error) - This is the line pressure pressure control solenoid in the transmission. Problem with high current on the circuit, compared to what is commanded. With this code set the trans is set to max line pressure and you will experience harsh shifts. Can cause premature transmission wear and damage.
11-09-2016, 09:25 PM
#17
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Join Date: Oct 2016
Location: Indiana
Posts: 32
Re: 95 z28 camaro rich with fuel and flooding
Scan isn't really useful. You have to let the car warm up enough, and wait long enough for the time limit for closed loop to elapse. Then the PCM will turn off the AIR pump and will go into closed loop, where it uses the O2 sensor feedback to adjust the fuel. You only ran for 58 seconds. Normal engine run time out on the timer is 206 seconds. Basically, let the engine idle at least 4 minutes while logging it. Then if you an actually drive it, we can see how the PCM is adjusting the fuel under various driving condition. There is nothing to be gained by blipping the throttle (which you did twice) while it's operating in open loop.
Right now, at idle, the PCM is using the long term fuel trims to add 25% extra fuel. That's based on what the PCM had to do last time it operated in closed loop. But with the AIR pump running, and the PCM not being in closed loop, the O2 sensors are showing very lean, because of the air being injected into the exhaust by the AIR pump.
Was the exhaust smelling rich while you were doing the data log?
Scan log also shows:
66: A/C refrigerant pressure sensor circuit (open or shorted) - Appears your A/C system is not operating. Has it been deleted? This code indicates the pressure sensor may be unplugged or the wires shorted.
73: Pressure Control Solenoid (PCS) circuit (current error) - This is the line pressure pressure control solenoid in the transmission. Problem with high current on the circuit, compared to what is commanded. With this code set the trans is set to max line pressure and you will experience harsh shifts. Can cause premature transmission wear and damage.
Right now, at idle, the PCM is using the long term fuel trims to add 25% extra fuel. That's based on what the PCM had to do last time it operated in closed loop. But with the AIR pump running, and the PCM not being in closed loop, the O2 sensors are showing very lean, because of the air being injected into the exhaust by the AIR pump.
Was the exhaust smelling rich while you were doing the data log?
Scan log also shows:
66: A/C refrigerant pressure sensor circuit (open or shorted) - Appears your A/C system is not operating. Has it been deleted? This code indicates the pressure sensor may be unplugged or the wires shorted.
73: Pressure Control Solenoid (PCS) circuit (current error) - This is the line pressure pressure control solenoid in the transmission. Problem with high current on the circuit, compared to what is commanded. With this code set the trans is set to max line pressure and you will experience harsh shifts. Can cause premature transmission wear and damage.
11-10-2016, 11:04 AM
#19
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Re: 95 z28 camaro rich with fuel and flooding
I've only used Bosch in imports. Based on posts I've seen on this site, over the past 18 years, many people have problems with Bosch. Use only AC Delco.
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
11-10-2016, 01:44 PM
#20
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Join Date: Oct 2016
Location: Indiana
Posts: 32
Re: 95 z28 camaro rich with fuel and flooding
I've only used Bosch in imports. Based on posts I've seen on this site, over the past 18 years, many people have problems with Bosch. Use only AC Delco.
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
When i get some spare cash ill get ac delco
here is new scan
https://www.sendspace.com/file/4puldh
Last edited by Bryson_bones; 11-10-2016 at 01:47 PM.
11-11-2016, 11:37 AM
#22
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Re: 95 z28 camaro rich with fuel and flooding
i just rescaned it and it is throwing this again are these o2's bad already 44: Bank 1 (Left) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated)
64: Bank 2 (Right) heated oxygen sensor (HO2S) Circuit (lean exhaust indicated)
11-11-2016, 01:40 PM
#23
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Join Date: Oct 2016
Location: Indiana
Posts: 32
Re: 95 z28 camaro rich with fuel and flooding
I've only used Bosch in imports. Based on posts I've seen on this site, over the past 18 years, many people have problems with Bosch. Use only AC Delco.
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
I still have the original AC Delco sensors that came with my car when I bought it new in 1994. Even though I no longer run in closed loop (heavily leaded race fuel can kill O2 sensors), and don't use a stock PCM for controlling the engine, the stock sensors are still plugging the O2 bungs on the headers. I can read them off the Scanmaster LT1 display on my dash, and they still appear to be working, in spite of having been doused with leaded fuel (VP Fuels C16 - 117 motor octane, 120+ research octane).
11-11-2016, 04:58 PM
#24
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Join Date: Oct 2016
Location: Indiana
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Re: 95 z28 camaro rich with fuel and flooding
one thing i noticed today while checking to see if i had any leaky injectors was the car sounds like it has a big *** vacum leak somewhere and the idle is very bad like 1500 when it starts goes down then when i'm driving down the road at 1500 again until i come to a stop. Maybe this the reason why it is running rich and miss firing?
Last edited by Bryson_bones; 11-11-2016 at 05:27 PM.
11-11-2016, 07:23 PM
#25
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Re: 95 z28 camaro rich with fuel and flooding
I'll look for symptoms of those problems in the data log. Just have too many things going on right now. Try to look at it Sunday.
11-11-2016, 08:54 PM
#26
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11-14-2016, 10:27 AM
#27
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Re: 95 z28 camaro rich with fuel and flooding
Everything in the data log is pointing to a large vacuum leak, or simple air bypassing the MAF sensor. Idle is above target RPM, and the IAC is almost fully closed and can't bring it down. MAF reading is maybe 50 to 60% of what I would expect to see.... example 5.1 grams/second at 1,000+ RPM. MAP at idle is slightly higher than I would expect, and MAP is inverse to vacuum.... high MAP = low vacuum.
The long term fuel trims are at 160 in all the cells that are fully developed (you have driven in those cells enough for the LTFT's to stabilize). That means the long term fuel trim multiplier is 1.25 ...... adding 25% more fuel than the PCM would normally add, based on the NAF reading. Then the PCM is using the short term fuel trims to add even more fuel..... they are up to 195, meaning the multiplier is 1.50 .... since the multipliers are in series in the fuel calculation equation, the PCM is adding almot 90% extra fuel, compared to what the MAF told it to add.
You have to look for the leak.... could be a vacuum line, intake manifold gaskets, EGR connection, leak in throttle body gaskets, or as simple as a huge tear/hole in the rubber intake elbow. And clean the MAF sensor if you haven't already.
Have you checked the fuel pressure, out on the road with the engine under load? Fuel pressure would have to be down to about 15 PSI to cause a 50% reduction in fuel flow. Not likely, but worth a check. And make sure there's no fuel in the fuel pressure regulator vacuum line.
I don't think there's anything wrong with the O2 sensors. They show exactly what I expect them to show from a cold start.
The long term fuel trims are at 160 in all the cells that are fully developed (you have driven in those cells enough for the LTFT's to stabilize). That means the long term fuel trim multiplier is 1.25 ...... adding 25% more fuel than the PCM would normally add, based on the NAF reading. Then the PCM is using the short term fuel trims to add even more fuel..... they are up to 195, meaning the multiplier is 1.50 .... since the multipliers are in series in the fuel calculation equation, the PCM is adding almot 90% extra fuel, compared to what the MAF told it to add.
You have to look for the leak.... could be a vacuum line, intake manifold gaskets, EGR connection, leak in throttle body gaskets, or as simple as a huge tear/hole in the rubber intake elbow. And clean the MAF sensor if you haven't already.
Have you checked the fuel pressure, out on the road with the engine under load? Fuel pressure would have to be down to about 15 PSI to cause a 50% reduction in fuel flow. Not likely, but worth a check. And make sure there's no fuel in the fuel pressure regulator vacuum line.
I don't think there's anything wrong with the O2 sensors. They show exactly what I expect them to show from a cold start.
11-20-2016, 12:16 AM
#29
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Re: 95 z28 camaro rich with fuel and flooding
well a few days ago when i read your reply i went and checked my intake elbow and it was all dry rotted and nasty lookin so i ordered a new one put it in and its runnin like a champ. thank you for the help fred 
12-14-2016, 12:46 PM
#30
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Re: 95 z28 camaro rich with fuel and flooding
Everything in the data log is pointing to a large vacuum leak, or simple air bypassing the MAF sensor. Idle is above target RPM, and the IAC is almost fully closed and can't bring it down. MAF reading is maybe 50 to 60% of what I would expect to see.... example 5.1 grams/second at 1,000+ RPM. MAP at idle is slightly higher than I would expect, and MAP is inverse to vacuum.... high MAP = low vacuum.
The long term fuel trims are at 160 in all the cells that are fully developed (you have driven in those cells enough for the LTFT's to stabilize). That means the long term fuel trim multiplier is 1.25 ...... adding 25% more fuel than the PCM would normally add, based on the NAF reading. Then the PCM is using the short term fuel trims to add even more fuel..... they are up to 195, meaning the multiplier is 1.50 .... since the multipliers are in series in the fuel calculation equation, the PCM is adding almot 90% extra fuel, compared to what the MAF told it to add.
You have to look for the leak.... could be a vacuum line, intake manifold gaskets, EGR connection, leak in throttle body gaskets, or as simple as a huge tear/hole in the rubber intake elbow. And clean the MAF sensor if you haven't already.
Have you checked the fuel pressure, out on the road with the engine under load? Fuel pressure would have to be down to about 15 PSI to cause a 50% reduction in fuel flow. Not likely, but worth a check. And make sure there's no fuel in the fuel pressure regulator vacuum line.
I don't think there's anything wrong with the O2 sensors. They show exactly what I expect them to show from a cold start.
The long term fuel trims are at 160 in all the cells that are fully developed (you have driven in those cells enough for the LTFT's to stabilize). That means the long term fuel trim multiplier is 1.25 ...... adding 25% more fuel than the PCM would normally add, based on the NAF reading. Then the PCM is using the short term fuel trims to add even more fuel..... they are up to 195, meaning the multiplier is 1.50 .... since the multipliers are in series in the fuel calculation equation, the PCM is adding almot 90% extra fuel, compared to what the MAF told it to add.
You have to look for the leak.... could be a vacuum line, intake manifold gaskets, EGR connection, leak in throttle body gaskets, or as simple as a huge tear/hole in the rubber intake elbow. And clean the MAF sensor if you haven't already.
Have you checked the fuel pressure, out on the road with the engine under load? Fuel pressure would have to be down to about 15 PSI to cause a 50% reduction in fuel flow. Not likely, but worth a check. And make sure there's no fuel in the fuel pressure regulator vacuum line.
I don't think there's anything wrong with the O2 sensors. They show exactly what I expect them to show from a cold start.