Need Help with my 92 LT1
Thread Starter
Cruising
Joined: Jan 2011
Posts: 10
Likes: 0
From: Chattanooga TN
Need Help with my 92 LT1
Ok, this thing is driving me crazy, its running too rich and sometimes has an rough idle, it drives ok and has good power under throttle, I have replaced every sensor on it, the opti-spark, plugs, wires, coil, control module, TPS, temp sensors, air intake temp sensor, o2 sensors, im runnig out of stuff to replace have spent a bloody fortune trying too straighten it out and am at the end of my rope, the only thing left are the injectors, I have allready ohm tested them and all is well, but I thought maybe one was hanging up or sense they are not factory injectors some dummy put 40lb per hr injectors on a factory LT1 or something like that. anybody out there had this problem? HELP!!!!! also there are no codes in the computer.
Last edited by pcmusicer; Mar 1, 2011 at 04:29 PM.
Racer
Joined: Apr 2006
Posts: 327
Likes: 0
From: edgerton WI
Check your fuel pressure regulator. Pull the vacuum line off turn the key to run but do not start. If fuel comes out of the regulator, change it. Also check your fuel pressure. This will let you know if you have a bad injector or a bad regulator leaking extra fuel. I say test first change one part later. Not change part to see If it's bad. Saves time and money.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Having the right parts installed in regard to programming will definitly make a difference.But I have to ask the question, what brand of O2 sensors did you use. Some brands just don’t work properly as the original or correct part.
Thread Starter
Cruising
Joined: Jan 2011
Posts: 10
Likes: 0
From: Chattanooga TN
checked the Pressure regulator, not leaking, so I guess i will check the fuel pressure, what should the pressure be?
I was only saying about the injectors because I can tell by the color they are not factory they are yellow, they were on the car when I bought it. The exhaust is gas smelling and sometimes it will load up to the point of dying, one note to make is it is much worse on a cold day, it idles well on a warmer day but still smells like raw gas coming out of the exhaust. The o2's are AC Delco, I heard vetts didnt do well on Bosh o2's so i sprung for the higher priced AC's, I am a pretty good mechanic but old school, also just asking but the guy I bought it from keeps insisting the ASR is causing it, but I cant see where traction control would have anything to do with it. (not working ASR Light is on) but I guess I could be wrong.
I was only saying about the injectors because I can tell by the color they are not factory they are yellow, they were on the car when I bought it. The exhaust is gas smelling and sometimes it will load up to the point of dying, one note to make is it is much worse on a cold day, it idles well on a warmer day but still smells like raw gas coming out of the exhaust. The o2's are AC Delco, I heard vetts didnt do well on Bosh o2's so i sprung for the higher priced AC's, I am a pretty good mechanic but old school, also just asking but the guy I bought it from keeps insisting the ASR is causing it, but I cant see where traction control would have anything to do with it. (not working ASR Light is on) but I guess I could be wrong.
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Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
Here is some info from the '92 FSM. This might give you a starting point. If the injectors are not equivalent to stock, or the ECM has been reflashed, that may have a bearing on your problem. Did the symptoms exist when you got the car, or did they develop later?
Drifting
Joined: Dec 2004
Posts: 1,313
Likes: 5
From: Middle Tennessee
NEVER troubleshoot car problems by replacing parts! 
That is more expensive than taking the car to a stealership. Granted, I have been guilty of this mistake myself in years past and have learned this lesson the hard (expensive) way. This forum has tons of expertise available to everyone and we all can benefit from that as our members are more than willing to help one another. Always come here and ask for help if a problem is kicking your tail. We have all been there, done that.
That is more expensive than taking the car to a stealership. Granted, I have been guilty of this mistake myself in years past and have learned this lesson the hard (expensive) way. This forum has tons of expertise available to everyone and we all can benefit from that as our members are more than willing to help one another. Always come here and ask for help if a problem is kicking your tail. We have all been there, done that.
Le Mans Master
Joined: Mar 2001
Posts: 7,999
Likes: 14
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
I have a set of stock injectors I had serviced by FIC sitting in the closet.
If you want them PM me, I'm heading for Nashville tomorrow and if you are anywhere near exit 2 on I75 or off I24 we could arrange a drop off. Or I could drop off on Sunday on my way home.
My email is jaa2404 at hotmail dot com
If you want them PM me, I'm heading for Nashville tomorrow and if you are anywhere near exit 2 on I75 or off I24 we could arrange a drop off. Or I could drop off on Sunday on my way home.
My email is jaa2404 at hotmail dot com
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Just on a chance, check the temperature sensor (ECT) in the front of the water pump. If it is open, or the connections to it are not good, the ECM will not like that and there will be a real rich condition.
Check the digital readout for engine temp in your speedometer. If that looks good and responds normal to what the engine temp should be ambient temp and hot, then it is probably OK. As long as the digital does not read "LO" you're probably good. Measuring the ECT sensor with a meter can be a real challenge to get in there and make good contact on recessed pins on the front of the pump.
68* reads about 3500 ohms and 194* reads about 241 ohms.
Also if running the O2s to rich for to longer time can damage the O2 sensor. I don’t know what the exact time line would be and factors would make it vary.
I would check for codes also. You may find something in this case that might give you a clue. I would want to know especially if there was any O2 codes or related items. I would clear the codes and check again.
Check the digital readout for engine temp in your speedometer. If that looks good and responds normal to what the engine temp should be ambient temp and hot, then it is probably OK. As long as the digital does not read "LO" you're probably good. Measuring the ECT sensor with a meter can be a real challenge to get in there and make good contact on recessed pins on the front of the pump.
68* reads about 3500 ohms and 194* reads about 241 ohms.
Also if running the O2s to rich for to longer time can damage the O2 sensor. I don’t know what the exact time line would be and factors would make it vary.
I would check for codes also. You may find something in this case that might give you a clue. I would want to know especially if there was any O2 codes or related items. I would clear the codes and check again.
