I just bought this 91 Trans Am 5.0 TPI car last week so I have no history other than its from the original owner, 80,000mi and well mantained.

It ran good but I wanted to do my own mantainance so I installed :
NEW Dist Cap, Rotor, Wires, Plugs & Fuel Filter to replace all the original items.

It ran good for 4 days then all of a sudden it would barely idle, surges, misses & if you touch the throttle it will die.

It had a code 32 so I replaced the old EGR
relaced all vacuum lines and checked operation of EGR controller, same thing, ran like crap.

I checked fuel pressure, fuel regulator (as good as it can be checked), TPS voltage and operation w/MT2500, IAC operation, verified spark and injector pulse wave forms with a Vantage, all good. Since the Ignition Module appeared to be slightly corroded, I installed a new Ignition Module and while I was in the area AND to take it out of the equation, I installed a new Ignition Coil to complete the secondary voltage side.

I checked the injector resistance after reading all the posts about bad injectors..........I guess its not an un-common problem to have multiple injectors bad at the same time.

There were three in the 10.1 to 10.9 range and the other five were in the 16.0 to 16.4 range.
All-Data states resistance values should be 15.8 to 16.6 @ 68 degrees ambient.

No, I did not run the engine while having the bad injectors unplugged. I understand that will help verify a shorted coil in the injector since the ECM will not function properly with a shorted injector.

 

Well I ordered a set of (8) injectors and a upper plenum gasket set.
I will post again when completed !

 

Just curious, is your cat toast ? Recently had the same problem, changed out the fuel pump, injectors blah blah blah, ended up being a broken middle honey comb in the cat "there are 3 in there", started as soon as I cut the cat, all power was there, no more heavy surging, and I can acheive 20 mph again in a heart beat ! "instead of 10 mins"

 

my car has no cat, it has a test pipe.

 

Yep, those 3 are definitely low. I betcha' if you ohmed them warm, they'd be worse and a few more might be bad.

 

Started taking it apart here.............https://www.thirdgen.org/forums/tpi/...fuel-rail.html

 

I am having THE SAME problem... what did ya find?

 

Ok so I ran out and checked this out:

Bank #1

Cyl #1 16.4 ohms
#3 14.9 ohms
#5 1.1 ohms
#7 12.3 ohms

Bank 2

#2 14.8 ohms
#4 12.3 ohms
#6 14.4 ohms
#8 16.6 ohms

So deffently 3 5 is FUBAR do you think this enough to make the driver go crazy and not send an injector pulse?