My chevy K3500 is driving me nuts

I have a 91 chevy K3500 That has been giving me problems it first started as a little sputter and fart every now and then when it got to running temp Now it will start and run just fine till it gets up to temp. I shut it off then go to restart turns over just fine but wont start at all once its at running temp. I took care off the two obviouse things it could be (the coil pack and the Ignition control mod) But now I'm out of ideas. it's definitly getting fuel and I also replaced the plugs Please any ideas will help

Thanks everyone

Almost forgot it also makes a high pitched whine that seems to be coming from the back of the block somewheres but once it warms up it stops doing that  

high pitched whine from the back of the engine is probably the distributer failing..

the upper bushing is probably Dry and about to seize...

sorry.. this does happen on these models..   there are after market Reman distributers available with lifetime warrantee for just over 100 bucks..  these have an improved reluctor and pick up coil design that work so much better than the original design..

this is what the replacement looks like..



i have had a bunch of these TBI distributers fail.. .one failed so bad.. that there was a clicking noise where the tip of the rotor was knocking against the terminals inside the distributer cap..

do your self a favor...

PRESET the engine before you remove the distributer...

take the cap off... leave the rotor on.. identify which spark plug wire goes to the #1 cylinder on the drivers side front...   bump the engine around until  the rotor is pointing in that direction...

now.. the timing mark should be close..  turn the crank in normal direction of rotation. . usually by turning the fan belt with your hands or a 15/16 socket on the front of the alternator pulley..

turn the crank until the timing marks line up for the specs on the sticker.. .. or until the tips of the pickup coil and the reluctor line up... as that is going to be base timing..

if you get it right.. it will be REALLY close... so you can remove and replace the distributer and once you get it to drop on the oil pump shaft .. you can turn the housing to align the pickup coil with the teeth and then lock it down.. this allows you to restart the motor without needing to turn the housing while somebody cranks..

there is a tan and black stripe wire inside the passenger foot well at the top of the carpet that needs to be disconnected to set the timing with a light... this disables the electronic timing advance for adjustments..

dead stick timing like i described above will get you really really close.. .  

Wunder24 welcome to Super Chevy:

Very common problem with the GM small distributor.

If the distributor checks out okay. I would do a wet and dry  compression test. You didn't say how many miles are on your engine? But it could be cam and timing chain time...

The whine does it sound like a high pressure fluid whine. If so check the trans fluid.

Bob