1994 performance problem
Thread Starter
Racer
Joined: Aug 2012
Posts: 289
Likes: 41
1994 performance problem
I have been working on a 1994 base coupe with a performance problem. It runs well in closed loop but pings and backfires once it get into closed loop. I have replace the TPS sensor and both O2 sensors, code 64 showed up and than code 42. I put new gas in the tank and added sea foam to the gas. The car runs noticeably better and seems to improve as I put miles on. I get no coeds presently. I am hoping the computer takes time to reset. I have to take a break to replace a leaking heater core and power antenna mast. I just rebuilt the head lights motors. I bought this car to tinker on in retirement. It has great paint, good interior, good tires. The big things have been replaced before I purchased the car. The opti spark, water pump, fuel pump, fuel filter and the main computer have been replaced. I also think the injectors were replaced as well.
My question is...... The car runs much better but not 100%. Could it get better with miles? If it does not what should I look to replace next?
My final comment is to thank all the folks that respond to this forum. With your help I have fixed many corvettes over the
Years!!
My question is...... The car runs much better but not 100%. Could it get better with miles? If it does not what should I look to replace next?
My final comment is to thank all the folks that respond to this forum. With your help I have fixed many corvettes over the
Years!!
Melting Slicks
Joined: Nov 2007
Posts: 2,830
Likes: 147
From: Gainesville FL
FPR is an easy check ... if there is fuel in the vacuum line to it then it has a bad diaphragm.
Are wires and plugs OK?
Advanced
Joined: Jun 2017
Posts: 73
Likes: 3
From: Tampa FL
Good luck with the heater core replacement. I recently did mine. Get lots of baggies for bolts and take lots of pictures. Almost everything has to come out do to it right.
I wouldn't expect the running to improve much more. All the computer is calculating and storing is your sort and long term fuel trims. Are you able to watch the sensor readings live?
What are the temps running when its pinging and backfiring, just after entering closed loop?
I would use something like EEHack to record some drives and see if you can pickup any need for a tune. I would also use a professional injector cleaner because it never hurts to clean a 25 yr old car's injectors.
I wouldn't expect the running to improve much more. All the computer is calculating and storing is your sort and long term fuel trims. Are you able to watch the sensor readings live?
What are the temps running when its pinging and backfiring, just after entering closed loop?
I would use something like EEHack to record some drives and see if you can pickup any need for a tune. I would also use a professional injector cleaner because it never hurts to clean a 25 yr old car's injectors.
