Starts great if it sets for two hrs. But if you drive it shut it off for twenty min. It sputters and floods keep cranking it will eventually start. And several shops have had it. Stump The Chump.

 

I did with a 68 gto. Turns out my timing was 180 degrees out.

 

it can be super frustrating when trying to diagnose rough idle conditions and poor running issues. regardless of how many shops that its been to...its easy to overlook the basics... i.e. compression test (wet and dry,) check your spark plug wires, gap the plugs, proper firing order, etc. once you've covered your bases, its wise to check for vacuum leaks....as these motors are really particular when it comes to vacuum leaks.

 

What WE don't know is the year of your vehicle; why don't YOU tell us?

Older vans, especially, with carburetors, were prone to vapor-locking, which has symptoms similar to those you describe. There's a butterfly valve in the exhaust with a bimetal spring. When the engine is cold, the butterfly valve diverts exhaust gases to provide a hot spot under the carb for fast warm-up, after which it rotates out of the way. I the bimetal spring rusts and breaks, the butterfly can flop around and send heat to the carburetor after it doesn't need it anymore, resulting in vapor lock. Other things can cause vapor lock as well.

 

Heya Tony, welcome to the forums.

There's no way to know what's going on without first knowing what you're working on. EFI and carb are two totally different animals with their own totally different share of issues.

Go into your user settings and put your year, make, and model in your signature. This helps us to quickly see what vehicle you're working on without us having to ask.

 

leaky injectors. If you have them.

There. Try that!

heh

t

 

EFI? Check the coolant temperature sensor.