Crimson Zer0

Well after some help from some guys around me, i got my 86 to run. They changed the fuel pump and then i changed the fuel filter and coolant and oil and all that stuff. But at will start(be it tough some times) and will go good until it stops the cold start thing when it idles at about 800. And it will sit there good, but if i rev it at all it will then drop the rpm's and try to stall.
After searching around i couldnt find anything like this or what to try, but I did see that it might be a vacuum leak. Any helpo would be greatly appriciated.

BlaCkPlaGUE

If it was a vacuum leak, your idle would be much higher than 800rpm.

So is this any kind of throttle, as in you press your foot down very very slowly and it still stalls?
Replacing the fuel pump was a clear elimination of one problem for this, same with the fuel filter. All I can say is that if it builds up RPMS if you press the throttle ever so slightly and increase it, and the engine spead increases, that would be a good sign of a very clogged cat!
If thats not the case, and no matter how slow you hit the gas it stalls, that would be very interesting.. Im not sure.

If you can, jack the car up, and disconnect the downpipe from the manifold.. yes I know it will be loud when you run it with it off, but we can eliminate or pinpoint a clog in your exhaust system this way.

Also, just for kicks, adjust the TPS. since your cold start is still equipped, you will have to wait until you get to operating temp to adjust it. Get it to running temp thats at 800rpm, turn the car off, disconnect the battery, and do the TPS adjustment from
www.fc3spro.com
all you need is a digital voltmeter set to kohms.

ANyways, try these two things then get back to us.

Oh yea, another thing, check out the air filter as well, if its severley clogged this **** can happen i spose as well.

Crimson Zer0

Ill have to check the air filter. But as for the stalling. It wont stall immediatly after i hit the gas it will rev good and stay there but when i let off the gas it will drop to lik 400 and sputter and try to die, if i press the gas and feather it alittle i can get it to settle at like 800 and run good. This car has been sitting for liek 4 years and i am trying to get it back to running good. Thanks for the help man,

BlaCkPlaGUE

eh, then the above advice isn't really going to help you. All I can think of is that the AFM is not shutting properly, when the air does not continue to flow in. The spring could be shitty or maybe the afm is caked in dirt. Check that out..

pengarufoo

check the bacv, you can remove it and clean it out if it's all carboned up... it's basically the IAC if you're familiar with that from other cars.

Also, it could be a vacuum leak.

BlackPlague said if it was a vacuum leak the idle would be high, this is not necessarily true. With a metered air based engine management system you can have vacuum leaks anywhere between the air flow meter and the combustion chambers which will affect operation. Vacuum leaks that occur between the throttle body and the combustion chambers raise idle, ones that occur before the throttle do not raise the idle, but still let in unmetered air.

Does the car want to die when you turn on accessories, like headlghts, or defroster.. ?