My 85 Pulsar wont idle when hot

Joes85NX · Apr 20th, 2004, 03:18 PM

(Cross-posted) Hello everyone! This is my first post in this forum! I have a problem I'm hoping someone can help me with. I have an 85 Pulsar NX that I've owned since it was brand new. So I don't want to get rid of it. The car starts up perfectly fine, but as soon as it warms up, it stalls. It doesn't spit and spudder before it stalls, it just stalls, as if someone turned the ignition off. The car will start right back up, but as soon as you leave your foot off the gas pedal, it dies. I've checked and replaced every vacuum hose under the hood. There are so many freakin' emissions control units, I don't even know what to begin to check, or even if they would cause the problem I am experiencing. If anyone has any leads on what I should check, please let me know. Thanks!

Gsolo · Apr 20th, 2004, 06:23 PM

Quote:

Originally Posted by Joes85NX

(Cross-posted) Hello everyone! This is my first post in this forum! I have a problem I'm hoping someone can help me with. I have an 85 Pulsar NX that I've owned since it was brand new. So I don't want to get rid of it. The car starts up perfectly fine, but as soon as it warms up, it stalls. It doesn't spit and spudder before it stalls, it just stalls, as if someone turned the ignition off. The car will start right back up, but as soon as you leave your foot off the gas pedal, it dies. I've checked and replaced every vacuum hose under the hood. There are so many freakin' emissions control units, I don't even know what to begin to check, or even if they would cause the problem I am experiencing. If anyone has any leads on what I should check, please let me know. Thanks!

hmm, interesting....sounds like as soon as it comes onto closed loop it dies cause something somewhere isn't wokring...i'm sure someone else knows this though

B11sleeper · Apr 20th, 2004, 07:01 PM

ok, this only happens once the temperature gets up to the mid point on the gauge, right?

I would look at the thermal vacuum switch, and other temperature related switches. if it's not that check the coolant temperature switch, the one that tells the ecu when the coolant is up to temp.

Myetball · Apr 20th, 2004, 08:04 PM

Does it run if you keep the gas pedal pressed or pump the gas pedal? Sounds like the fuel flow is not sufficient to keep it running once the idle speed control valve retracts and the idle settles down to normal.

For fuel flow you're looking at a clogged pickup screen in the tank, clogged fuel line, failing fuel pump, clogged fuel filter, carb problem. Check the sight glass on the passenger side of the carb, fuel level should be to the middle of the glass.

Joes85NX · Apr 23rd, 2004, 10:36 AM

Thanks for your replies. I'll have to do some checking. The car will run if I keep the pedal depressed. I can manually take the idle down to around 1000 rpm or so, then it starts idling rough and dies. I just depress the pedal a little, and it will start right back up and run and smooth as silk. But as soon as I take my foot off the pedal, it dies. I agree that it must be something temperature related, but I just don't know where to begin checking. I don't want to start throwing parts at it, because that can get expensive quickly. Thanks a ton for your help, guys!

Joes85NX · Apr 23rd, 2004, 10:38 AM

By the way, where is the idle speed control valve located? Is that the large flying saucer looking thing right near the throttle? Can that be bad?

Myetball · Apr 23rd, 2004, 04:56 PM

Quote:

Originally Posted by Joes85NX

By the way, where is the idle speed control valve located? Is that the large flying saucer looking thing right near the throttle? Can that be bad?

The idle speed control is that big black alien looking thing on the drivers side of the carb. It is designed to kick up the idle when the car is cold. As it warms up, the little piston retracts and the idle settles down to normal.

You may have a primary vacuum leak. Check all the vacuum lines coming off the intake manifold and the carb. There are some on the underside of the manifold that you can't see but will have to stick you hand up there and feel around.