I have a problem that I cannot figure out and could really use some help.
I took the car out of winter storage about two months ago. It ran great the first three times I had it out. I brought the car out again last week and it starting acting up and it is still doing it.
The car goes extremely lean at 10-60% throttle. I have seen the afr go between 16 - 25 and it hesitates as if the car cant pull its own weight. Now I have been working on it for three days now and I thought I would be able to figure it out but im lost. It is really bad in third/four gear. If I have it in third or fourth at 2000 rpm and go above 60% throttle the car hesitates for three seconds, the afr goes above 16, but then the car afr drops to 11-12 and it takes off like it should. If I do the same but leave the throttle under 60% the car continues to hesitate and the afr stays at above 16. I also have a slight vibration at idle, almost like a misfire as you can hear it pop in the exhaust. At idle the afr is 13.4 - 14.3
Here is a list of what I have done and checked so far:
I first replaced all spark plugs because I have had a hesitation before and it was the spark plugs the last time (The last time the afr did NOT go lean).
After that didnt fix the problem I checked all sensors in the car. The maf sensor gives values between 5 Gm/s at idle to close to 200 Gm/s at full throttle. The tps sensor ranges from .6 to 4.57 volts and has no dead spots. I also checked the MAP sensor.
I then measured all the coils at the top two prongs and they were .7 ohms cold and .9 hot. Everything I have read says the coils should be under 1 ohm. Is this correct?
I did a KOEO and KOER test and it reported missing egr (which has been deleted and turned off in the tune) and o2 sensors rich and not switching. I replaced both o2 sensors and the problem still persists. I redid the KOER test and it only reported the missing egr.
I also looked into the fuel pumps and FRPS but everything seems fine. At all points in the throttle the car maintains 39 psi give or take 3 psi.
So to sum up I have ruled out basically everything but tune and computer. From what I have read the computers either seem to fail or work but not act up. Have any of you ever heard of a tune changing or somehow going bad? I plan to reflash the tune in today sometime but I was hoping someone here could give me some other ideas or places to look.
I usually just look into problems and fix them myself but this time I am lost and could really use the help. Thanks in advance to any ideas you guys may have.
I took the car out of winter storage about two months ago. It ran great the first three times I had it out. I brought the car out again last week and it starting acting up and it is still doing it.
The car goes extremely lean at 10-60% throttle. I have seen the afr go between 16 - 25 and it hesitates as if the car cant pull its own weight. Now I have been working on it for three days now and I thought I would be able to figure it out but im lost. It is really bad in third/four gear. If I have it in third or fourth at 2000 rpm and go above 60% throttle the car hesitates for three seconds, the afr goes above 16, but then the car afr drops to 11-12 and it takes off like it should. If I do the same but leave the throttle under 60% the car continues to hesitate and the afr stays at above 16. I also have a slight vibration at idle, almost like a misfire as you can hear it pop in the exhaust. At idle the afr is 13.4 - 14.3
Here is a list of what I have done and checked so far:
I first replaced all spark plugs because I have had a hesitation before and it was the spark plugs the last time (The last time the afr did NOT go lean).
After that didnt fix the problem I checked all sensors in the car. The maf sensor gives values between 5 Gm/s at idle to close to 200 Gm/s at full throttle. The tps sensor ranges from .6 to 4.57 volts and has no dead spots. I also checked the MAP sensor.
I then measured all the coils at the top two prongs and they were .7 ohms cold and .9 hot. Everything I have read says the coils should be under 1 ohm. Is this correct?
I did a KOEO and KOER test and it reported missing egr (which has been deleted and turned off in the tune) and o2 sensors rich and not switching. I replaced both o2 sensors and the problem still persists. I redid the KOER test and it only reported the missing egr.
I also looked into the fuel pumps and FRPS but everything seems fine. At all points in the throttle the car maintains 39 psi give or take 3 psi.
So to sum up I have ruled out basically everything but tune and computer. From what I have read the computers either seem to fail or work but not act up. Have any of you ever heard of a tune changing or somehow going bad? I plan to reflash the tune in today sometime but I was hoping someone here could give me some other ideas or places to look.
I usually just look into problems and fix them myself but this time I am lost and could really use the help. Thanks in advance to any ideas you guys may have.
