...Something else goes wrong. My car has been running great lately. I just began installing my NOS kit 2 days ago, working a few minutes a day on it. All i have left to do is hook up the fuel feed line and nitrous feed line to the selenoids and i am ready to go. Today, for some odd reason, my car got a really horrible idle up and down from like 400 to 750 whenever im idling. It used to idle smooth at 550. I havent changed anything from yesterday when it was running fine. My BLM was at 129. Things I have checked are Plugs wires are fine, cap, rotor, and plugs are all new, NO vacuum leaks. Could it be the IAC or maybe my TPS was knocked out of adjustment. I tried to unplug my battery to reset the computer's memory and this did nothing. Am I on the right track? Does anyone have any suggestions?
thanks alot

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*1989 RS
*Red, Daytona Turbo fiberglass hood, chrome 16x8 IROC wheels
*355 CID
*TPI ported plenum, SLP siamesed runners, Edelbrock high flow intake
*SLP 1 and 3/4 headers with 3 inch catback
*Richmond 3.73, Auburn Posi
*Modded 700-R4, 2800 stall converter
*eibach pro kit and hotchkis strut tower brace

"There is no way you have a 350 in that car. They are made to have 305's and a 350 wouldnt fit"
-local parts store genius-

 

Hmmmmm... could be the TPS... cause you have to do some work around the TPS to install nitrous system stuff, right? Trace your steps back at what you changed or had to remove.

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1988 Pontiac Trans Am GTA L98 5.7L, Black on Black with 114,000kms.

Best ET 14.559 @ 95.25MPH
Custom 3" Stainless Exhaust Y-Pipe back (High flow Cat and Flowmaster Mufler)

 

Thanks for the suggestion. I found the culprit. It was adead altenator. Thirdgens suck for altenators, everyone i know has had problems with them. As far as i know EFI doesnt wrok too well with no juice
thanks again

------------------
*1989 RS
*Red, Daytona Turbo fiberglass hood, chrome 16x8 IROC wheels
*355 CID
*TPI ported plenum, SLP siamesed runners, Edelbrock high flow intake
*SLP 1 and 3/4 headers with 3 inch catback
*Richmond 3.73, Auburn Posi
*Modded 700-R4, 2800 stall converter
*eibach pro kit and hotchkis strut tower brace

"There is no way you have a 350 in that car. They are made to have 305's and a 350 wouldnt fit"
-local parts store genius-

 

OK, i guess i was wrong. The altenator just happened to die at the same exact time. Anyway, I have developed a huge exhaust leak where the collector meets up with the y pipe. can that possibly cause a rough idle? Im going to clean out the IAC tomorrow and fix the collector and pray that this horrible idle goes away

------------------
*1989 RS
*Red, Daytona Turbo fiberglass hood, chrome 16x8 IROC wheels
*355 CID
*TPI ported plenum, SLP siamesed runners, Edelbrock high flow intake
*SLP 1 and 3/4 headers with 3 inch catback
*Richmond 3.73, Auburn Posi
*Modded 700-R4, 2800 stall converter
*eibach pro kit and hotchkis strut tower brace

"There is no way you have a 350 in that car. They are made to have 305's and a 350 wouldnt fit"
-local parts store genius-

 

Yes, a bad exhaust leak can cause the engine to run rough, especially if it's sucking clean air back in to the exhaust and messing up the O2 sensor. Fix that and see if things return to normal.


------------------
Rob P
89RSconvtZZ4TPI Edelbrock Intake
SLP Dual Cold Air Intake 1 5/8" Headers Semi-Siamesed Runners, IROC
suspension, alum shaft. Numerous mods.
92Z28convt5spd (stock)
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Was that a typo that your car idles at 550 normally? That's a little low isn't it? Just wondering.

 

Well, the exhaust leak was the problem. It idles smooth at 550 so i didnt think it was any sort of problem.

------------------
*1989 RS
*Red, Daytona Turbo fiberglass hood, chrome 16x8 IROC wheels
*355 CID
*TPI ported plenum, SLP siamesed runners, Edelbrock high flow intake
*SLP 1 and 3/4 headers with 3 inch catback
*Richmond 3.73, Auburn Posi
*Modded 700-R4, 2800 stall converter
*eibach pro kit and hotchkis strut tower brace

"There is no way you have a 350 in that car. They are made to have 305's and a 350 wouldnt fit"
-local parts store genius-