That bout says it. '87 Trans Am 305 TPI w/5 speed. Seems to run a little rough under low rpm and low throttle cruising conditions. Plugs and wires are both new, i'm thinking maybe dirty injectors? Not good with TPI, hope you guys can help

 

Other possibles:

IAC dirty.
Distributor Pickup Coil Bad.

 

Thanks for the reply. I replaced the IAC, but haven't looked into ignition problems yet. Guess I should do that. Seems like one of the more likely causes to me.

 

One word EGR!!!!!!!!!!!!!!!!!!! disconnect line from solenoid and see what happens. My problem disappeared.

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89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Moroso Crank Bolt and roller pilot bearing.
New Fuel Pump!
Autometer Vac+Oil Temp
2000 Yamaha R1 150hp 385ibs

 

I seem to have the same problem with the stumbling. I don't have an EGR hooked up at all. Brand new plugs/cap/rotor , I cleaned the IAC out. But i think it may still have a small problem. May replace it soon.

 

EGR!!!!!!!!!!!!!!!!!!!
HMMMMMMMMMMMMMMMMMMMMM

That's an interesting idea. Hadn't thought of that one yet. I'll give it a shot this weekend. Thanks.

 

I have a similar problem with my 89 LB9/5 speed... sometimes when i hit 2000 rpms in 1st or 2nd it stumbles and feels as though it's going to backfire, but never does. I was thinking maybe I need a new fuel filter, but I really don't understand TPI that well, either.

Feels like it's just not getting as much fuel as it needs at that point, and it only happens once in a while, but after it happens once, it tends to do it several times until i start the car up again.

Jon


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89 GTA
Beautiful Gunmetal gray, LB9 305 and T5 tranny. Only 60,000 miles!
Dual cats, 3"flomaster
Accel 300+ Ignition, wires, cap, coil, etc
Airfoil
KN Airfilter
Removed Screens on MAF

 

How would one clean his IAC?

Jon

------------------
89 GTA
Beautiful Gunmetal gray, LB9 305 and T5 tranny. Only 60,000 miles!
Dual cats, 3"flomaster
Accel 300+ Ignition, wires, cap, coil, etc
Airfoil
KN Airfilter
Removed Screens on MAF

 

I only have one suggestion if all else fails. If you have removed your MAF screens put them back in i know it sounds weird but give it a try if nothing else works. The computer may be jumping out of the reading boundaries due to the increased airflow. Just a thought hope it helps