98 hard to start when warm

1998 chev c1500 replaced original 4.3 with a 2002 4.3. Runs fine until you go to start it after it gets up to normal temp, then it barely turns over at all. The distributor was pulled out and replaced. Timing controlled by ecm but what if it was a notch off, or maybe coil? After it sits awhile it starts fine. Any clues?

Did you check the timing??

If you mean it cranks slow, its probably the starter. I've never seen a 4.3 crank slow due to timing. You can check the starter by doing a starter cranking amp draw test. High amp draw indicates a short in the windings.

If understand right the timing is controled by the computer (no adjustment) thats why i'm wondering if he could have got it a notch off. He thinks coil. But yes when i start it cold no prob, but after warm up it drags or barely turns over if at all on start up till cool down. Didn't think about the starter would drag after warm up.

Yes the timing is set by the computer but the distributor still has to be the right place..I believe it is 0 degrees...

I recall the chevy starter getting hot and dragging.
There was a shield to add that kept the manifold heat from getting it so hot.
Bob B

1998 chev c1500 replaced original 4.3 with a 2002 4.3. Runs fine until you go to start it after it gets up to normal temp, then it barely turns over at all. The distributor was pulled out and replaced. Timing controlled by ecm but what if it was a notch off, or maybe coil? After it sits awhile it starts fine. Any clues?

check the connections to the starter and also the battery/grounds ..then I would replace starter..when the starter gets hot from the engine heat this causes the starter to loose torque..an old starter is sussepible to this heat///bad connections/grounds also add to this issue ..