Truck stalls after driving for 15 min

[OBSMando]

a year ago a brought a 1995 Chevy from Mexico to Orlando after it came from Orlando the truck started having problems where the truck would run for a good 15 mins then stall and won’t turn back on until the truck cools off.
I’ve changed fuel pumps fuel filters changed fuel fuses aswell still can’t find the problem I also noticed that when the truck stalls the injectors would start to smoke when ever I would open the hood it’s a 4.3

 

[PlayingWithTBI]

A wild guess? Either your ignition coil and/or ICM are bad and fail with heat.

 

[Schurkey]

What is the fuel pressure WHEN IT STALLS and when it's running good?

A plugged fuel tank vent could make it impossible to pump fuel after several minutes of running; and take a long time for the in-tank vacuum to relieve.

No promises on the smoking injectors, unless low fuel pressure is causing the injector duty cycle to get so long that the injector solenoids are overheating. This is TBI, I presume, not one of the kinda-rare batch-fire spider systems? I have a buddy with a Pre-'96 4.3L and the prehistoric spider.

As always, connecting a scan tool is a good idea.

 

[OBSMando]

What is the fuel pressure WHEN IT STALLS and when it's running good?

A plugged fuel tank vent could make it impossible to pump fuel after several minutes of running; and take a long time for the in-tank vacuum to relieve.

No promises on the smoking injectors, unless low fuel pressure is causing the injector duty cycle to get so long that the injector solenoids are overheating. This is TBI, I presume, not one of the kinda-rare batch-fire spider systems? I have a buddy with a Pre-'96 4.3L and the prehistoric spider.

As always, connecting a scan tool is a good idea.

didnt check that but i also notice that my fuel pump relay heats up really badly not sure if that's causing the truck to stall.

 

[HotWheelsBurban]

Sounds like there's too much resistance somewhere, the relay or wiring harness, for that relay to be overheating like that.

 

[Schurkey]

The resistance is probably burnt contacts IN the relay, or burnt/corroded connections that the relay plugs into.

IF (big IF) the oil pressure bypass wiring isn't operational, burnt relay contacts would reduce voltage to the fuel pump, reducing fuel pressure...maybe stopping the pump altogether.

 

[Dariusz Salomon]

didnt check that but i also notice that my fuel pump relay heats up really badly not sure if that's causing the truck to stall.

Mine runs pretty hot too. It may be pigtail or relay socket-when it gets too hot loses contact. When it stalls does pump still run-can you hear it?
Also when it stalls measure the voltage on relay socket-see if any of it changes-first measure when it's fine so you know what it should be like. Ton of videos on youtube. Like this i.e.

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[Chevyed20]

I'd say ignition module in the distributor. Check if it loses spark when it stalls. Ignition coils usually spit and sputter at all times or just flat out die.

 

[Erik the Awful]

Pull your ignition control module and check to see if there's any thermal paste between it and the distributor housing. If not, it can't transfer the heat away and will overheat and stop running. It's a gooey white paste that wipes off fairly easily.

If there's no thermal paste, get some - you don't need very much, and the cheapest stuff will work. Put a thin layer on the bottom of the ICM, as if you're trying to glue it in place without any oozing out the side.

 

[Schurkey]

Is there ANYONE who installs an ignition module and doesn't use the thermal paste?

I've been dicking with cars for decades, and I've never once seen a module without the goo underneath.