Reman 350 stumbles and misses

[Billyon24s]

Hey guys,

So a few months back I swapped a autozone 350 into my 85 C10, I broke it and it did fine for the first few weeks, then after a few weeks of driving it, The motor gained a miss, it wasn’t bad at first then it’s gotten to the point where it stumble when you give it throttle and if you put a load on it, the miss will come back and misses pretty good.

Now normal idling it doesn’t have the miss at all but once you put a load to it is when it does it, could it be a timing or valve issue causing it to do that? I’ve had This issue for a few months now and it’s driving me nuts not knowing what’s going on with it

 

[1lejohn]

Do you think the cam was broken in correctly? The dizzy may have moved if the hold down bolt isn't tight. The carb has some trash in it? The fuel pressure is low. It could be any of these. The simple checks in my mind are the following. I would check the timing. I would check the plugs and wires. I then would pull the valve covers and check the rockers and push rods maybe one is loose, if you don't find anything wrong with the first two checks. Then maybe move on to the fuel side of engine. Good luck with it.

 

[Bextreme04]

Pull some spark plugs and take a look. They could be getting oil fouled from an intake or valvetrain issue or just carbon fouled if the engine was running rich.

 

[fast 99]

If a cam or valve issue is suspected a vacuum gauge will show it.