The Stovebolt Site Forums The Shop Area Engine Shop Popping/Hesitation

Ok here goes. I have been scouring posts and web pages trying to sound like I know what I am talking about...but being a newbie you will able to see right through me. I can change oil and plugs and maybe brakes but ends there. On my 66 with the 250...it seems to be running ok while cruising, but popping when decelerating or when temps outside or cold even when engine is warm. It hesitates bad when stomping on the peddle as well.

Sounds like accelerator pump in carb maybe? I will take filter off and check for this, but just came in from under the hood and when opening the throttle I do not physically see the distributor turning either. I can not turn it by hand with engine off, but should I be able to see it advance when pulling on the throttle? I want to learn all this stuff but like algebra it may take me a few tries.

Thanks,

Dennis

On your 250 you won't see the distributor move like the earlier 216/235 distributors. The advance is inside the distributor for your truck, the body of the distributor won't turn when clamped down. You might want to think about checking the fuel pressure and even do a compression test on your engine. After its warmed up take the air cleaner off and look down into the carburetor and then move the throttle, see if you get a good squirt of fuel. If not you either have a fuel supply issue or a bad accelerator pump.

Thanks Don...I guess it's good I don't see the distributor moving.

I did take off the air cleaner and it seems I do have a fairly healthy squirt of gas when hitting the throttle. The fuel pump was not replaced to long ago...but no reason it can't be going bad I suppose. I did have it in the shop after relocating to Colorado for a tune up for altitude and asked to have it re-timed and new points. It still really bogs when hitting the throttle hard...mainly when cold and running with a little choke helps. Easy on the throttle and there is not as much noticeable hesitation. Does this still sound more carb/fuel related or should I still consider timing/spark may be off? Thanks again.