89 350 TBI running bad.

[TopDogg]

I just bought an 89 4x4. 350 TBI auto. NO RUST I paid $1400.
I was a little undecided at first but now I think I did alright.

I knew truck was running bad when I bought it but now that i drove it more than once i can better describe problem.

Under load or heavy acceleration it will stall, spit and bog. In nuetral it will rev up fine.
If I accelerate to much and let off real quick I get a backfire on occasion.
I have hit the gas pedal a time or two when I start it so it will idle. After it starts it will idle fine.
If I am able to accelerate and I have it under a medium load I can slightly let up on the gas and it will actually PICK UP speed. HMMMMMMMM

The guy just put new cap, rotor,plugs on it last week. NO help.

I am pretty much trying to see if anyone has had this problem before I go and trouble shoot.

I will check EGR valve tomorrow. I guess the coil and pick up coil needs to be checked. Seems to be more of a timing/spark problem rather than a fuel problem.

Thanks for ANY suggestions.

[TopDogg]

TIMING is everything. I checked the timing and it was way off. Hold down clamp on distributor was loose. Now I have a good running rust free Chevy 4x4 for $1400.