I have been having problems with my 84' pickup 22r carb engine. This problem has been ongoing since my dad owned the truck. Typically what happens is that after doing usually over 65 MPH on the freeway or high revs going through gears my truck will not want to idle or will idle hard and I will have to press gas a bit to keep it idling while stopped to keep it alive. It also smells like it is running rich (smell fuel from exhaust). I have heard EGR valve and such, but I have somewhat ruled that out with the help of mechanics and so on. Sometimes the idle problem will go away within minutes after driving around for a while, other times I will park it and come back out some time later and it will fire up and idle normally, sometimes like now it will not idle for going on about a week now. Any ideas? THANKS!

 

Forgot to mention that it still has the original carb in it with about 200,000 on the engine

 

Check the auxiliary fuel pump on the side of the carb, sometimes the diaphragm will go bad and leak fuel into the vacuum lines causing idle problems.

 

It might be the secondaries sticking open ,the carb might just need cleaning and lube.