Highway stalling

[Therigwelder]

My 93 ranger 2.3 has developed an intermittent stalling issue at Highway speeds,this is my daily driver that I drive 200 miles a day. No problem firing up and runs good.i drive the first 40 miles of my journey with no problems and the truck is well warmed up. I get up on the highway and occasionally it will stall at 55-60 miles an hour, After I get to the side of the road at a complete stop the truck starts right up.Ive tried popping the clutch while the truck is rolling but it will not fire I must come to a complete stop.its happened 3 times so far and I drive to far from home to have an undependable truck.any ideas what is causing this problem? Damn near Everything in the truck is new.

 

[19Walt93]

How you describe it to a tech often decides if the repair will be successful. Stalling happens at idle, if it dies while driving we would say it cuts out or quits. If you have a tach, next time it quits look and see if the rpms are still reading. If the revs drop to zero while the engine is still turning it means the ignition stopped firing. Being a 93, my first suspicion would be a TFI module failure. If you replace it I'd use a Motorcraft part not a parts store generic piece. It might pay to check all the connectors to make sure they're tight and not corroded before replacing anything.

 

[Therigwelder]

Got it hooked up to my snap on this morning even though I don’t currently have the CEL lit up.KOER it shows an 11 code, everything is good. However with KOEO i have a group of stores codes that I am sure are related to each other.452,222,218,157. The coil packs,cps,ICM have all been replaced recently.the 452 may not be related to the other codes,that’s the rear sensor and shouldn’t have anything to do with engine performance.

 

[Therigwelder]

I have been working on the ranger today and desperately need it to run right my backup truck went down too. The codes I am concerned about are the 218 and 222 I believe these to be the ones causing the stalling issue.from what I’ve been able to gather these codes are ICM issues. The ICM, coils and CPS have been replaced with new about 4 months ago.I do know the icm’s are notorious for going bad.the ICM tests good but that doesn’t really mean anything.I need to figure this out badly

 

[RonD]

Always good to post the code definitions you are using with the codes

Also good to look up codes on a full list so you can see the codes the computer DID NOT USE, they can tell you as much as the codes it did use
List here: https://therangerstation.com/tech_library/3digitcodes.shtml

218 (M) IDM signal open or high or left coil pack failure - Ignition Systems
222 (M) IDM open or high or right coil pack failure - Ignition Systems

Its possible the ICM is overheating at high demand, but tests OK when cold
Did you use a heat sink grease on the back of it when installing the new one on the intake, that helps it stay cooler


The computer doesn't have a "running out of gas" code, no fuel pressure sensor
At highway speeds fuel demand is high, so a partially clogged fuel filter or "sock" in the tank may limit fuel flow so engine just "runs out of gas"
But assume new fuel filter?

1994 ICM wiring here, 1993 is the same

 

[Therigwelder]

Yes,filter is good. I pulled the coil connectors off one at a time and the rpm dropped slightly almost unoticable on the intake coil.dropped substantially on the exhaust side. While I had the connector off I had no spare coming from the wire towers. Once I had the connectors back on all 8 towers were producing good hot fire.in my mind I think that says the ICM is cutting out intermittent,when it’s well warmed up.the truck dies just like I turned the key off. No stumble,shake backfire. Bam just off

 

[RonD]

And did you use grease on the ICM when it was installed?

Yes, the 2.3l or 2.5l Limas ran on 4 spark plugs from 1974 to 1988, and unplugging one coil pack tests if the 4 spark plugs on the working coil pack are OK, no misfires

The dual spark plugs are strictly for performance, so you should lose power/RPMs with only 4 working spark plugs
Not sure why one set of plugs would cause more of a drop in RPMs, are you sure it wasn't a misfire on one of those 4 spark plugs?

 

[Pflames]

Check the wiring harness for the switch that cuts the fuel pump in case of an accident. I just had the same exact thing happen to me. The insulation was worn and cracked, causing intermittent shut offs.
Good Luck

 

[Therigwelder]

Problem solved:apparently the ICM was losing ground when these codes set.I took the ICM off the truck, drilled and tapped the 4th hole that ford didn’t supply I then applied heat sink paste on the ICM and bolted it back in place. I have found these ICM’s can cause all kind of crazy issues.I drove the truck 200 miles today and it didn’t kill.

 

[RonD]

Good work

Thanks for posting the FIX