LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Help LT1 Problem

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Old Feb 16, 2014 | 06:36 PM
  #1  
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Default Help LT1 Problem

I'm having an odd issue with my 1996 Trans Am. It will start up and idle perfectly fine on a cold start. It runs and drives after that for a good 20 minutes or so, but once it warms up it starts acting up at highway speeds. It will sometimes backfire and die. Then once it dies or I turn it off after it's already warmed up it's a struggle to get it started again. I've replaced the opti and MAF already but I'm definitely no mechanic so if anyone could help me with this I would appreciate it. If there's any troubleshooting I could do to determine what it is just let me know.

Thanks,
Chris
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Old Feb 16, 2014 | 09:22 PM
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a few things

1. wrong lt1 section
2. mileage
3. plugs/wires ever changed?
4. potential fuel issue. how old is your filter and pump?
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Old Feb 17, 2014 | 10:44 PM
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ICM heat related failure maybe - try spacing it (and the coil) out from the head by stacking some washers in there, to see if it gets better.
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Old Feb 18, 2014 | 06:17 PM
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I figured out the issue with the misfire and dying at high RPMs. It was carbon build up in the throttle body. I got all that cleaned and it runs and idles perfectly when warm. But there is still a starting issue. And like I said before, that's only an issue when it's warmed up. It will start perfectly fine when it's cold. I plugged in a computer and it throws a Coolant Temperature Sensor code. Could that be it? I replaced it not too long ago and checked the connector for voltage, seems to be working fine.
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Old Feb 18, 2014 | 07:01 PM
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that shouldnt give it trouble starting up. since the TB was so dirty have you ever cleaned the MAF?
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Old Feb 25, 2014 | 04:58 AM
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Yes I purchased a brand new MAF and cleaned out the throttle body really good. Now it just has the starting issue. Can't figure it out.
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Old Feb 25, 2014 | 11:48 AM
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Originally Posted by chr1s
I'm having an odd issue with my 1996 Trans Am. It will start up and idle perfectly fine on a cold start. It runs and drives after that for a good 20 minutes or so, but once it warms up it starts acting up at highway speeds. It will sometimes backfire and die. Then once it dies or I turn it off after it's already warmed up it's a struggle to get it started again. I've replaced the opti and MAF already but I'm definitely no mechanic so if anyone could help me with this I would appreciate it. If there's any troubleshooting I could do to determine what it is just let me know.

Thanks,
Chris
What kind of opti did you use? Codes? Most of the parts store ones are crap, best to go AC delco or MSD... seems like opti to me:

Symptoms:

* Car suddenly dies and won't restart
* Starts but immediately dies
* Extended cranking to start
* Rough idle
* Sputtering
* Backfiring
* Trouble reaching higher rpm
* Black smoke from exhaust
* Poor performance with car warmed up
* Weak plug wire spark
* Codes 16, 36, and 42 may be set ??????

Read more: http://www.gmhightechperformance.com...#ixzz2uMC9oXhw
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Old Feb 25, 2014 | 12:09 PM
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Default My suggestion

I had the exact problem. As a few members have already mentioned check you plug wires. I did all the other things mentioned but when I got the plug wired changed it disappeared.

Good luck.
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Old Feb 25, 2014 | 08:09 PM
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Check the ICM as someone stated before, could also be the starter. Id check the ICM 1st
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