Second edit 4-15-22... Ignore all comments on heat soak issue.

This repair DID NOT resolve heat soak issue.

Edit 4-10-22...new ICM solved issue. If you have a "heat soak starter" problem you might want to read to my last post in this thread. Thanks to all that replied.

*Begin OP 4-9-22* vvvvv

With key at run...

Have 12v at coil + (white/blue) AND 12v at coil tach (green/yellow) with ICM unplugged.

At ICM (distr mount grey) unplugged have 12v @ tach (grn/yel) , tfi power (white/blue) , AND 12v at start (red/grey?black?)

12v test light at coil tach @ start test... no flash...continues to be brightly lit continuously.

I am not a wiring guy...just following the manual. Any help is appreciated.

Thanks...MOe.

 

The switching wire (tach) when disconnected from ICM and disconnected from coil reads 4.2v with key in run position.

That seems weird.

 

Coil is new but tested it anyway.

Primary .5
Secondary 8,110

Within specs.

 

23 TPS out of range
67 Neutral drive switch open

 

A new MasterPro 6 pin is $45 at O'Reilly's. That's the direction I am leaning at present.

 

So you have good fuel pressure verified with a mechanical gauge but have no spark? What is a MasterPro 6 pin? Remove the spout. Do you now have spark?

 

I have fuel pressure...not verified...but I did check that the rail is pressurized and I smell fuel when I crank it.

Checked spark with an inline spark tester at plug and thru coil wire.

MasterPro six pin is the name brand of the grey ICM I can get at O'Reilly's.

Removed sprout...mine is black and square...no change in output to the drk grn Tach wire to the coil. Test light Still brightly lit with key at run...dims slightly but no pulsing while cranking. Also tested with inline spark tester without sprout...no spark.

Also tested the inline spark tester in the other truck and it is working.

 

Are you getting a signal to the fuel injectors?

 

That does mean there is enough pressure for it to start and run. Does the selected fuel pump run for a couple seconds and then shut off or does it run continuously?

A few guys have links to testing the distributor sensor (PIP?). If you did a search I’m sure you could find a few threads with those tests. My phone doesn’t allow me to paste them here.

 

I Haven't checked the injector signal yet. Would that keep me from getting a spark pulse at the coil?

 

Fuel pump runs for a few seconds and then stops. I'm looking around for the diagram of the Diagnostic Test Connector to see which pin to jumper to get continuous fuel pump activation. No luck on that yet. I went down to O'Reilly's and borrowed a fuel rail pressure tester but the instructions in my Chilton manual says jumper the fuel pump test pin...but doesn't explain how to do it.

Thanks...I'll check it out. Got an ICM...now trying to find a bit that fits the screws.

Found a video that says it is a 5.5...I assume mm...but my 5.5 won't fit in the hole.

 

...for a Module Tool...

 

Couldn't get the distributor turned far enough to get on the rearward screw due to the large knurled part of the tool....so I cut it in half. XD



If you are reading this to find a solution to a similar issue...the ICM replacement solved my issue...truck is running as much like new as it was before it quit.

Wife needs me...more to follow later.

Thanks to all that replied.

 

Tl;Dr ... Been struggling with a "heat soak starter" issue for months...maybe longer. Truck would start great cold...but at first a 30 min drive at interstate speed would cause the starter to crank extremely slowly. Usually is would not start until it sat for 20-30 minutes and cool down. I replaced the starter, shielded the starter, put on another shield, wrapped a shield around it, replaced positive and negative battery cables, added a second ground wire AND replaced the battery.

At this time I believe the the ICM was the culprit all along.

_________

Long story long....

The "heat soak" condition was getting worse...so that even a short trip to the store a mile away may result in slow cranking and a no start condition. While I was tightening a replaced positive battery cable at the starter relay (what I call the starter solenoid on the fender by the battery) I broke the stud out if the old relay and had to replace it. Of the three Duralast standard starter relays I received...every one of the the plunger would hang and continue cranking the starter for 30 seconds or more after ignition had occured. At first I believed this was a new symptom...but it was just bad parts. A Duralast Gold starter relay solved that problem (knock on wood).

While STILL at AutoZone the truck wouldn't start at all. Not directly after replacing the starter relay for the forth time...but the same day. I was still chasing that "heat soak" issue and was back at the parts store and it gave up completely.

Tried ether...nothing. Didn't even try to start.

A new multimeter at Autozone was half as much as a tow home, and I didn't have the other tools I needed anyway...so $60 for a tow.

After realizing I didn't have spark from the coil...I took a WAG at it (Wild *** Guess) and replaced the ignition coil. $42

No joy...but I have no idea how long that old one had been there. Money well spent IMO...YMMV.

Then it was to my FAVORITE part (read with as much sarcasm injected as humanly possible)...the multimeter and the 12v test light. I call this my favorite part because this is the area where I am weakest. Give me carburation, points and condensors and adjustable valves any day...but please Lord save me from the voltage and the ohms.

Anyhow...that's where post one starts...good luck if you're diagnosing a crank no start issue. If you're dealing with a "heat soaked starter" issue like mine...I HIGHLY recommend having your ICM tested at the parts store.

The Module Tool at O'Reilly's is part #W1216... it's in with the hanging tools.
$6.

I used the Chilton manual for the testing procedures abd specs.

The Ignition Control Module (ICM) for my 1989 302 CID (5.0L) RWD is distributor mounted and grey...it is part #2-7019.
$45 lifetime guaranteed.
​​​​​

I have a electric metal bandsaw that I cut the Ignition module tool in half with...but a hacksaw would have done it.

Thanks to all who responded.

Good luck...