Once again, no start when hot.

[Keeper]

No codes? Crank sensor?

 

[DeCaff2007]

No codes? Crank sensor?

Intermittent ICM and knock sensor codes, but really only once the engine gets up to operating temp.

Pre-vortec. No crank sensor.

 

[Keeper]

Intermittent ICM and knock sensor codes, but really only once the engine gets up to operating temp.

Pre-vortec. No crank sensor.

oops... I logged 89 as 98 in the op. Good luck with it.

 

[PlayingWithTBI]

I know they didn't come that way from GM, that's why I asked.

Even TBI can get vapor lock - that's why most 454s and some HD 350s came with the "Hot Fuel Module" to run enough gas through the system to blow out any vapor bubbles. So, I guess vapor lock is a possibility however improbable it is.

 

[1madmouse]

If this only happens when hot have you tried the starter? Mine would act like no turn over or fire when hot had to put a shield on the starter solenoid and it never did it again. That was about 15 years ago

 

[Medic0893]

Had a similar issue turned out to be the coil. Other possibility would be the ignition module. Both are sensitive to heat, working normally cool and cutting out with heat.

 

[docstoy]

3 distributors in a month ? What if the wire terminals in connectors have lost or loosing tension when hot, that's if it cranks but no spark but you have fuel pressure , I hate not having all the pieces to a puzzle because it's hard to figure out . And a lot of times we cause the problem(s) ourselves, now I'm talking about myself, follow diagnostic procedures from service manual for your application, don't skip steps because the last time I ckd it , it was good, I've also done that before and kicked myself in the backside for my own stupidity. Follow service procedures and should be able to find and repair problem.

 

[RegMo]

Mine will do that when it gets hot took me forever to figure it out and it turned out to be the fuel pump relay overheating, only way I found it was running it in my drive till it happened and finally after several times swapped the fuel pump relay just for the hell of it and cranked right up. Might be worth trying

 

[Hell Knight Hicks]

May sound dumb but I had a truck that would periodically not start after running just fine. It ended up being the oil pressure sending unit on the back side of the engine near the distributor. Replaced that and it started reliably ever since. Until it was totaled many years later.

 

[PlayingWithTBI]

after several times swapped the fuel pump relay just for the hell of it and cranked right up. Might be worth trying

It ended up being the oil pressure sending unit on the back side of the engine near the distributor.

It has to be both to kill it. The Oil Pressure Switch is backup for the Fuel Pump Relay.

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