Kashdon

I have a 1987 carbureted 5.8 v8 f250, when I first start it after it completely cools down it idles really rough and will stall if I do not keep slight constant pressure on the gas. once it sits for 10 ish minutes and warms up it idles nice and normal. Even if u let it warm up for ten minutes lots of the time it will stall when you put it in gear (reverse or forwards) sometimes if you let it warm up long enough it doesn’t but you have to let it warm up for a long time. I can get it in gear without it stalling if I keep very slight pressure on the gas then switch it in to gear and immediately giving the gas 2 hard pumps then drive and try not to stop. If I let it warm up for 5 and do that if I stop at a stop sign or light it’s fine but likes to stall when I go to accelerate. Once at operating temperature it runs stops and goes perfectly. (I should add that it never has problems starting) I was looking at the choke and when you start the truck the choke works like it’s supposed to and opens but it goes from closed to fully open in about 2 minutes I don’t know if that’s too fast or not. And once it’s open, when the truck cools down and it should close it doesn’t it stays open and you have to give it a slight hit then it goes back to closed. Any ideas? Is the choke thing related or a different problem?

Kashdon

I should add, it seems to idle really low but I can’t tell because it doesn’t have an rpm gauge.

raski

The choke should not go from closed to fully open in two minutes. That's too quick and you will have greater difficulty when winter sets in. You need to check the components associated with the choke. That includes the bi metal choke thermostat and the choke pull off diaphram.
You need to obtain a tachometer to verify proper idle speed. There is an adjustment for that.

Kashdon

Ok thanks I’ll look in to that