91birdofprey

I have a 1991 trans am gta 5.7 tpi.

The problem is that if i unplug the first on fuel injector the the drivers side, the car will start and run great , but right when i plug it back in the car dies. If i start on all 8 cylinders it will start and die right away. Thanks for the help ahead of time. took it to some mechanics the couldn't figure it out either.

91birdofprey

anyone?

dirtywhiteZ28

Double check the vacuum lines, especially the one for the fuel pressure regulator. If you have the tools, check fuel pressure at the rail, then do a flow test, make sure your getting adaquate fuel volume. If that car has a remote mounted coil and I think it does, it wouldn't hurt to Ohmm test the coil lead. Your not getting enough fuel,or the coil can't support the demand for all 8 cylinders.

91birdofprey

I installed a new coil. still same problem.

dirtywhiteZ28

The wire, check if it has a problem between, the coil and the dist.

TORN

iTrader: (17)

Shorted injector coil? Did you Ohm out your injectors to see if they are all the same? They should Ohm out to 16 Ohm.

southbay08

Any injector that reads 12ohm or less is indicative of coil failure.

www.southbayfuelinjectors.com
516-492-6504

91birdofprey

Thanks for the help guys it turned out you were right, four injectors were bad. So i replaced them all for a set of 8 LT1 injectors i found on craigslist for $50 it runs better than ever! But you were my second choice if i didn't buy those southbay08. Thanks for getting me back to condition. (:

southbay08

No worries! Happy that everything worked out for you.

www.southbayfuelinjectors.com
516-492-6504

Brighton

Why is 12 the threshold? I thought they should all be 16 ohm. I replaced 4 at first and years later had the other 4 go below 16. The first time I had one or two that went from maybe 14 to 8 once I keyed up and the pump pressurized the fuel lines.

The first time the problem was it went lean (verified by watching O2 voltage) when I tipped into the throttle to pass someone. The second time the car would shutter/buck when I was accelerating moderately from a stop light. It felt like I was driving on a washboard surface.

I learned my lesson and now have Bosch injectors in the car.

southbay08

12 isn't exactly the "threshold" but once it starts going below that then once again it is indicative of coil failure. Think about it, you are running injectors that test out at 16ohm, then they read 14ohm, then 11-12ohm.... they are beginning to fail. Besides if you feel like doing some research, the stock injectors that were used in the tpi set ups "multecs" are known to be extremely prone to coil failure.
There are alot of good injectors out there but i am with you... bosch is the way to go.

jibbio

I must say i just stumbled upon this earlier today... this tread has certainly confirmed my finding... 2 of my injectors were read 4 omhs... will be changing them out... does anyone know if that can have anything to do with the o2 sen reading wrong on the scanner?? thanks ahead!

rayres88

What are the a few replacement injectors for a 91 GTA. I think I need to replace. Part #s brands?