1993 Hardbody stalls/loses power when hot

[ececil85]

I have a 1993 4WD Hardbody 2.4 motor manual trans that I just got running after sitting in the garage for almost a decade.
After I got it running it ran well for a week, but now after driving for about 10 minutes, it starts to stumble, lose power and stall at a stop or low speed, sometimes it sounds like it backfires. Runs like a champ cold, but it slowly gets worse until flooring it barely does anything. Most noticeable at higher RPMs in 1st and 2nd. Shutting it off and turning it back on will get it to run fine for about a 1/4 mile until it starts to lose power again. Letting it cool for even longer will get it farther.

It only happens when the truck is warm after 5-10 minutes, but I have replaced everything that I can possibly think of. The thing is, THERE'S NO CODES. After clearing the codes and running it, I get code 55, no malfunction. I need some ideas.

Here's what I've replaced so far:
Full tune up:
-Spark plugs
-wires
-distributor cap
-distributor rotor
-air filter

-ignition coil (used)
-ignition control module (new)
-crankshaft position sensor (used)
-oxygen sensor
-coolant temperature sensor

-emptied fuel tank
-fresh gas
-new fuel pump/pickup
-fuel filter
-fuel lines
-new vacuum lines
-sea foamed the intake
-ran lucas fuel injector cleaner in gas

-cleaned mass air flow sensor
-EGR is holding vacuum (same symptoms with EGR vacuum unplugged)
-checked the TPS and volts seemed to increase smoothly, unless heat triggers it to malfunction(?)

-disconnected exhaust before the catalytic converter to eliminate clogged exhaust

After replacing/checking all of this, NOTHING has changed. I appreciate any help

[PapaSmurf2k3]

Have you done a compression check while the engine is hot?

Maybe there's a vacuum leak somewhere?

[ececil85]

I have not run a compression test yet but if there was a compression issue wouldn't it show itself at all times? Cold and hot? I can drive a few miles with no problem but when it gets to operating temp it starts acting up. I can test the compression tho..just gotta find my tester.

I did a visual check for any vacuum leaks and replaced most of them. A couple of them looked cracked but no major leaks. There is a slight crack in a rubber hose that connects to the pipe that runs along the exhaust manifold and plugs into the bottom of it. Not sure even what that is? Don't think that would cause a major issue like this, I would expect a smaller issue like shaky idle

[tstockma]

Hey did you have any luck? One thought - if that replacement ignition coil is still a used one - make it new. A cold engine takes less juice to fire the plugs, so seein' how yours runs OK cold but loses it a few minutes later, the symptom might fit. You've done a nice job on the other ignition parts I would've suggested.

[ececil85]

Thanks. Today is actually the first day I've had a chance to work on it in a while. I was thinking that too, and last time I was at the junk yard I grabbed another one. I'll probably put that on today too. I also thought about using a volt meter on some of the sensors (mass air, TPS) while holding a hair dryer with light heat on them to see if that changes any of the readings.