intermittent very rich condition. unknown cause/trigger
09-05-2010, 07:49 PM
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intermittent very rich condition. unknown cause/trigger
92 civic hatch using p28. engine is a 96 fully built turbo gsr.
update 9-8: not the ignitor or coolant temp sensor or the ECU/chip. i have found that as soon as the richening out happens, if i shut the car off and turn it back on while driving, the AFRs return to normal. if the car DIES/STALLS and i restart it, they will remain rich.
my car has been tuned by a reputable local tuner.
situation: car runs with the correct AFR's 85% of the time. doesnt matter how i am driving. However, sometimes my AFR's will drop to 9.9-10.0 and remain there no matter how i drive. after anywhere from 10-60 seconds the AFR's return to normal.
normal idle is a steady 1100rpm. when AFR richens out, idle surges from 500-800rpm.
The car IS actually running rich. the sensor is not giving a false reading.
can some people please point me in the right direction to solving this problem.
thanks in advance, doug
update 9-8: not the ignitor or coolant temp sensor or the ECU/chip. i have found that as soon as the richening out happens, if i shut the car off and turn it back on while driving, the AFRs return to normal. if the car DIES/STALLS and i restart it, they will remain rich.
my car has been tuned by a reputable local tuner.
situation: car runs with the correct AFR's 85% of the time. doesnt matter how i am driving. However, sometimes my AFR's will drop to 9.9-10.0 and remain there no matter how i drive. after anywhere from 10-60 seconds the AFR's return to normal.
normal idle is a steady 1100rpm. when AFR richens out, idle surges from 500-800rpm.
The car IS actually running rich. the sensor is not giving a false reading.
can some people please point me in the right direction to solving this problem.
thanks in advance, doug
Last edited by EG6 Love; 09-08-2010 at 06:29 PM.
09-05-2010, 07:56 PM
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Re: intermittent very rich condition. unknown cause/trigger
92 civic hatch using p28. engine is a 96 fully built turbo gsr.
my car has been tuned by a reputable local tuner.
situation: car runs with the correct AFR's 85% of the time. doesnt matter how i am driving. However, sometimes my AFR's will drop to 9.9-10.0 and remain there no matter how i drive. after anywhere from 10-60 seconds the AFR's return to normal.
normal idle is a steady 1100rpm. when AFR richens out, idle surges from 500-800rpm.
The car IS actually running rich. the sensor is not giving a false reading.
can some people please point me in the right direction to solving this problem.
thanks in advance, doug
my car has been tuned by a reputable local tuner.
situation: car runs with the correct AFR's 85% of the time. doesnt matter how i am driving. However, sometimes my AFR's will drop to 9.9-10.0 and remain there no matter how i drive. after anywhere from 10-60 seconds the AFR's return to normal.
normal idle is a steady 1100rpm. when AFR richens out, idle surges from 500-800rpm.
The car IS actually running rich. the sensor is not giving a false reading.
can some people please point me in the right direction to solving this problem.
thanks in advance, doug
09-05-2010, 08:35 PM
#4
Re: intermittent very rich condition. unknown cause/trigger
A brief rich AFR should not cause a performance problem, such as the idle surge. I think the engine may be misfiring. Check the plugs, wires, cap, and rotor first and also consider the coil and igniter unit.
09-06-2010, 06:00 AM
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Re: intermittent very rich condition. unknown cause/trigger
yes chrome.
we actually stopped our tuning because the ignition was maxxed out, we were losing spark. i know my wires are arcing because they were brand new oem and now with 200 miles they are orange/brown. i had autozone check the ignitor since they are known to go bad on older hondas.
sounds like an ignition is a good place to start.
we actually stopped our tuning because the ignition was maxxed out, we were losing spark. i know my wires are arcing because they were brand new oem and now with 200 miles they are orange/brown. i had autozone check the ignitor since they are known to go bad on older hondas.
sounds like an ignition is a good place to start.
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09-10-2010, 07:03 PM
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Re: intermittent very rich condition. unknown cause/trigger
i ran it by jeff evans and he really thought it was the coolant temp sensor. he said, "The coolant temp or air temp sensor might be reading off for the time period the car runs very rich. I had a car that had a coolant temp sensor that would randomly read very cold (about 5 degrees) and the ecu would default add 30-40% enrichment trim like i was warming up."
it looks like you eliminated that but i figured i'd ask him.
it looks like you eliminated that but i figured i'd ask him.
09-10-2010, 07:21 PM
#12
Re: intermittent very rich condition. unknown cause/trigger
I would think that if the ECT sensor were falsely reading a cold engine, then the idle speed would increase above that of the warm engine. Instead, the idle speed is decreased. So I think a faulty IAT sensor is a better candidate. However, I don't think the IAT signal affects idle speed.
Also, earlier in the thread, you mentioned arcing plug wires and a spark problem. Has a misfire issue been ruled out?
Also, earlier in the thread, you mentioned arcing plug wires and a spark problem. Has a misfire issue been ruled out?
Last edited by Former User; 09-10-2010 at 07:46 PM.
09-11-2010, 10:44 AM
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Re: intermittent very rich condition. unknown cause/trigger
ANOTHER CURVE BALL. CAR HAS AN OPEN LOOP TUNE!
i agree that the problem im having sounds like an ect sensor giving a false reading sometimes. i will check my wiring again on the ect but i already tested the sensor per honda and i have continuity from the 2 pin connector and ecu.
when i ws tuning my car i was getting spark cut at 16psi and over 6500rpm. so i just turned the boost down to 12psi and i dont seem to have any problems with that much power.
i have heard that the ect has a bigger effect on fuel trim than the iat.
i agree that the problem im having sounds like an ect sensor giving a false reading sometimes. i will check my wiring again on the ect but i already tested the sensor per honda and i have continuity from the 2 pin connector and ecu.
when i ws tuning my car i was getting spark cut at 16psi and over 6500rpm. so i just turned the boost down to 12psi and i dont seem to have any problems with that much power.
i have heard that the ect has a bigger effect on fuel trim than the iat.
09-15-2010, 07:23 PM
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Re: intermittent very rich condition. unknown cause/trigger
HERE WE GO:
MAP sensor is not the problem HOWEVER I DID FIND....
with the car off i have 12.6V at battery.
with car running normally i have 14.4V at the battery.
with the car running like **** (very rich AFR) I HAVE NO VOLTAGE AT THE BATTERY.
is this a faulty alternator or voltage 'regulator' i believe its called?
LMK please
MAP sensor is not the problem HOWEVER I DID FIND....
with the car off i have 12.6V at battery.
with car running normally i have 14.4V at the battery.
with the car running like **** (very rich AFR) I HAVE NO VOLTAGE AT THE BATTERY.
is this a faulty alternator or voltage 'regulator' i believe its called?
LMK please
09-16-2010, 09:38 AM
#21
Re: intermittent very rich condition. unknown cause/trigger
I don't think so. To my knowledge, there's no fuse protecting output amps from the alternator white wire.
Explanations for the surprising 0V measurement across the two posts of the battery are either that the battery is bad or that voltage from the alternator white wire is grounding and neutralizing battery voltage. That's all I can come up with.
Explanations for the surprising 0V measurement across the two posts of the battery are either that the battery is bad or that voltage from the alternator white wire is grounding and neutralizing battery voltage. That's all I can come up with.
09-16-2010, 10:20 AM
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Re: intermittent very rich condition. unknown cause/trigger
well i know for sure the battery is good so your your second explanation sounds likely. ill keep you updated on what i find. wont be until tomarrow afternoon though.
thanks
thanks
09-16-2010, 10:30 AM
#23
Re: intermittent very rich condition. unknown cause/trigger
If you are unable to find a problem with the white alternator wire, then you possibly should consider replacing the battery even though you think it's good.
Have you repeated the 0V test result several times and found it to perfectly correlate with the engine problem?
Have you repeated the 0V test result several times and found it to perfectly correlate with the engine problem?
09-16-2010, 08:03 PM
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Re: intermittent very rich condition. unknown cause/trigger
i have swapped between 3 batterys already and no i have not repeated the test although i dont see why anything would change.
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