i'm working with an 86 TA 5.0 Auto, I was told from previous owner it has a mild cam. (all the info I have). Will idle but runs rough, smells like gas. I can't find any leaks. when you start to drive it seems to run fine. About 600 feet into driving it just completely falls off and dies. Ran the CEL it says MAF and TPS. i Unplugged the MAF the Car would not run at all. PLugged back in unplugged the tps same result.. Any help would be appreciated

 

only thing i can think of, because of my small amount of experience with carbs.
is it possible that the carbs are bad?

 

MAF and TPS indicates that his car is Fuel injected.. TPI

 

Whoops! my mistake! In that case i'd ohm the injectors to see if they are bad.
also another question, does the car die when brakes are applied

 

It will only die after a short drive.. can put in park, or drive and it will idle. It just runs rough. As soon as you get about 600 feet the rpms drop to about 200. then left off the gas and idle will go normal then apply gas it instantly dies. I'm pretty new to gm products so any help would be great thanks

 

Well i would do several things
1. replace the fuel filter it can and will hold fuel up from the engine.
2. if you can ohm the injectors to see if you have any bad ones.
3. look for any leaks.

these could find the problem, but i haven't had or seen this problem yet,
so stay tuned i might get more info later.

 

when you check the resistance of your injectors, try to check them when they are cold and hot....coils on those injectors tend to fail after they get hot. If you smell fuel, pull your plugs, if you have any wet cylinders you have a leaky injector. Also, check the diaphragm on your regulator.

 

I'll check that today. Will repost results

 

First thing I would do is check for a vacuum leak. Spray brake cleaners all around the intake. I would also check all the vacuum lines visually to see if any are dryrotted and cracked. Hook up a vac gauge and see what you get at idle, in park. IIRC a healthy engine should have between 15-19.

After that, fix the TPS and MAF problem first. The hook up a multmeter to the tps and check for good, smooth volt change from closed to open throttle. I forget the exact voltage they should be but for some reason .60v closed to 4+v open ring a bell. If its not smooth, replace it.

For the maf, replace the relays, they are only about 5 dollars a piece. After that, clean the maf with maf cleaner stuff. After that check the voltage to each pin going to the maf sensor. FWIW, when I had a maf problem that plagued my car for 2.5years, each time I thought I fixed it but kept coming back, it was a bad pigtail going to the maf. The funny thing is the pigtail looked great, but there was a short in the one of the wires and it would make the car run rough and stall out.