New Vette owner with big problems.
Thread Starter
4th Gear
Joined: Apr 2012
Posts: 4
Likes: 0
From: Cut-N-Shoot TX
New Vette owner with big problems.
Ran across a deal I couldn't pass up, but now I think I should have. It's a '90 Vette that had been sitting for a while. Someone has added a cam & headers, and possibly other stuff I can't see. I have replaced the fuel pump, injectors, tps, o2 sensor, and a couple other sensors. The problem is, it runs extremely rich. It runs great going down the road at higher rpm, but smokes at idle (fuel not oil) & keeps fouling the spark plugs..
I really don't know much about these engines & I'm not sure what to do. I'm guessing the cam has got the computer going crazy?? Any advice would be great!
I really don't know much about these engines & I'm not sure what to do. I'm guessing the cam has got the computer going crazy?? Any advice would be great!
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
If it has a lumpy cam you should notice it at idle and low rpm.
I suggest you get the ECM scanned to see what's up; it will show fuel correction tables as well as all sensor values.
Remember that year is speed density; i.e. uses manifold pressure and air time to determing air flow. Either of those sensors could cause false enrichment, but a scan tool should show the real story.
I suggest you get the ECM scanned to see what's up; it will show fuel correction tables as well as all sensor values.
Remember that year is speed density; i.e. uses manifold pressure and air time to determing air flow. Either of those sensors could cause false enrichment, but a scan tool should show the real story.
Racer
Joined: Jul 2004
Posts: 351
Likes: 3
From: amarillo tx
help
hi, if you can, contact corey henderson at henderson performance technologies and set up a dyno tune. he is in new braunfels tx and he is very good at tuning. i have been there several times and they treat me like a king, in other words, they have great coustomer service. he will share all that he knows about vettes if you ask. you will not be disappointed. see ya
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
hi, if you can, contact corey henderson at henderson performance technologies and set up a dyno tune. he is in new braunfels tx and he is very good at tuning. i have been there several times and they treat me like a king, in other words, they have great coustomer service. he will share all that he knows about vettes if you ask. you will not be disappointed. see ya
Corey is an expert he can sort it out real quick.
If it hasnt had one already it could be in need of a chip retune.
Coreys your man and knows C4s real well.
Le Mans Master
Joined: Mar 2001
Posts: 7,999
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
What brand O2 sensor did you put in?
Several folks have reported problems with Bosch sensors.
NTK or Denso are good replacements.
I had that problem on my 92 even with a new chip for the mods.
The o2 sensors just weren't responsive and NO codes
Several folks have reported problems with Bosch sensors.
NTK or Denso are good replacements.
I had that problem on my 92 even with a new chip for the mods.
The o2 sensors just weren't responsive and NO codes
Drifting
Joined: Aug 2004
Posts: 1,430
Likes: 2
I installed Bosch and had similar problems! I ended up ordering AC Delco from Napa. Big differance!
Thread Starter
4th Gear
Joined: Apr 2012
Posts: 4
Likes: 0
From: Cut-N-Shoot TX
Thanks for all the replies. I'm pretty sure it was a Bosch O2 sensor I put in. I'll start with changing that & go from there. I also just ordered a FSM to help me learn about the car. I would love to take it & have it dyno tuned, but that's just not in the budget right now.
Last edited by Cut-n-Shoot; Apr 7, 2012 at 01:52 PM. Reason: Typo
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From: moraga ca
hi, if you can, contact corey henderson at henderson performance technologies and set up a dyno tune. he is in new braunfels tx and he is very good at tuning. i have been there several times and they treat me like a king, in other words, they have great coustomer service. he will share all that he knows about vettes if you ask. you will not be disappointed. see ya
Thread Starter
4th Gear
Joined: Apr 2012
Posts: 4
Likes: 0
From: Cut-N-Shoot TX
Thread Starter
4th Gear
Joined: Apr 2012
Posts: 4
Likes: 0
From: Cut-N-Shoot TX
Update..
Just though some of y'all might want to know... I was talking with the guy I got the car from & he told me he had a new ECM that he never installed. I installed it & the cars runs great now. 
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From: Fredonia WI
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