i have a 89 TA with the L98. the other day it started running rough whhile i was out driving it so i took it home and let it sit about an hour started it back up and it ran fine. the next day i drove it around for about 6 hours it ran fine till the end of the day and it started running rough again. in park it has errratic idle and is pretty rough. so far i have changed plugs, wires, cap, rotor, fuelfilter and no change. i ohm tested the injectors and they where all right at 15. fuel pressure test was around 32-36 psi at idle but once i shut the car off it will slowly drop to 0 within 30 minutes. the previous owner had 2 injectors replaced because they where clogged. any suggestions? i am thinking that replacing all the ijectors is going to solve my problem?
any thing else i can try before injectors?

 

Hi there,
I replaced my injectors a while ago although my syptoms were different. Starting the car after it had been sat for about 15-20 minutes after a run would require a lot of cranking before it would fire. Basically the injectors were leaking down and causing a flooded situation. If you have the grey multec injectors they are likely to be getting tired. I'm not entirely convinced that injectors are the cause of your problem as you say it runs ok most of the time? If you do go down the injector route I would recomend searching southbay injectors in the U.S. They offer some great Bosch ones which they adapt to fit these engines.
Anyway, have you pulled all your spark plugs to check their colour condition? That would help identify if the problem was with a particular cylinder. Has your service engine soon light come on at all? There are other factors for you to consider such as the IAC valve (this would not typically throw an engine code... or maybe MAF sensor and have you checked for air leaks on the intake manifold?
Hope this is of some help, these intermittent faults are the worst!

 

It was intermittent it's constant now I looked at the injectors and there is 3 different types 2 of the grey multec, 4 black and silver, and 2 all black ones there is no ses light on but it does work. It starts up fine every time hot or cold that's why I am thinking maybe a plugged injector I just changed the pluggs and they where all the same