My 1990 5.8l has a starter problem that has everyone that I've talked to, stumped! When engine is cold, starter works great. When engine warms up, starter will turn over, but not fast enough to start engine. It acts like a dead battery or a dead starter, but when the engine sets for about 20 mins. the starter turns over just like it did when cold. I've changed starters three times, and they are all the same. Any ideas?

 

If I am remembering correctly engine timming can cause that to happen, I think is retarded and needs advancing, I may have it backwards though You can check your timming if you have a timming light. I have also seen a bad cable cause a similar problem.

 

Definately sounds like the timing. That's what I would try first.

 

I am having the same problem on my 1995 5.8l... It is harder to start when warmed up and feels like a dying battery (slow starter)...
With one slight twist: Occasionally absolutely nothing happens when I turn the ignition, not even a solanoid click. The battery light is on and the battery meter is in the mid position. I usually can start the truck after a couple minutes, but it is quite annoying.
Is this a timing issue as well?
Thanks Experts!

 

it couldn't hurt to check the timing...they're all over the place from the factory

starter could be having heat soak issues...in the case of the 1990, are you using a stock 1990 style starter? Try using a 93+ starter (pmgr type), double check your starter 12+ lead for bad terminal ends

another thing to consider...the main relay sucks. Try jumping the fender relay when this problem happens