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Please help with my severe problems

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Old 04-02-2006, 07:43 PM
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Car: 1988 IROC-Z
Engine: LB9
Transmission: 700R4
Please help with my severe problems

Hi, can someone please try and give me suggestions of what to do here.

I replaced my cam, intake, runners, pulley and lifters and got a custom PROM...

My car now has severe problems. It has a incredible lack of power. If you floor the gas it takes a second to take off and sometimes will rev up to the red line before it moves. Before I did the work I could easily spin the tires and it had awesome acceleration. It also idles erratically and will die in reverse.

I tried my best to set the timing right as I had to reinstall the distributor but it cannot be completely accurate due to the difficulty/impossibility of reaching the hold down bolt well, the confusing technique of unplugging, jumping the computer in order to do it so this might be the source of the problem...

It was pointed out to me also that i never reset my TPS cuz I never took it off the throttle body but it didnt occur to me that with the new runners, the plenum has to be at a different angle and therefor its probably way off.

Anyone have any other suggestions that could help me on my quest to figure out the problem. I wouldnt mind tearing it apart and replacing the cam again if I knew that was the problem. The stats are like .476/.450 203/210 116.

My other car info is in my profile.

Thanks a lot, any info will help!
Old 04-02-2006, 08:15 PM
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Car: 1987 IROC 1991 RS
Engine: 5.7 TPI 5.0 TBI
Transmission: T-5 , 700R4
Axle/Gears: 2.73 twice
What kind of PROM did you replace it with? I would start with the simplest things first, also check your vacuum lines, intake manifold gaskets, and post some more info on your parts.
Old 04-02-2006, 08:24 PM
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Did you degree tha cam or just stick it right in?
Old 04-02-2006, 09:34 PM
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Car: 1988 IROC-Z
Engine: LB9
Transmission: 700R4
I put the cam gear on the only way it can go on and then lined up the indent on the cam gear vertical with the indent on the crank so they meet perfectly and i am under the impression that this is sufficient. is that a correct assumption?

and the PROM i ordered from TPIS based on all my info and stats which i realize probably isnt perfect but since no one around me does them on site and i dont want to do it myself this was the best option. all of the intake gaskets are new and as far as i know there are no vaccuum leaks but i guess i dont know for sure...
i also heard that the tv cable on the throttle body might have become unadjusted? is that possible/could be a problem?
Old 04-02-2006, 09:57 PM
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Car: 1987 IROC 1991 RS
Engine: 5.7 TPI 5.0 TBI
Transmission: T-5 , 700R4
Axle/Gears: 2.73 twice
The tv cable would not be the cause of the problem, there is an article here on the forum for adjusting it, try plugging off all your vacuum lines (except for fpr) and see if there is any difference. As far as TPIS PROMs are concerned, I am not one to be skeptical, I would not have any info to help you on that area, may try putting in old PROM for reference.

It sounds like you set your cam correctly, just curious about timing...
Old 04-02-2006, 10:44 PM
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Car: 1988 IROC-Z
Engine: LB9
Transmission: 700R4
i ran the car a while beofre i put the new PROM in. when i put it in the engine ran much smoother and felt better but the power still didnt come back...with the stock chip it runs even worse
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