1995 F250, 7.5L XLT, hello, thought id start a blog on my never ending truck problems. Mine goes into limp mode when it gets over 104 degrees, which it does her in the desert for 140 days straight. 2nd year now. Enjoyed some success today, was pulling a 624 (besides my non running afternoon problems) scared my trani solonoids were going. Connector was wet with trans fluid. Changed fluid/filter, and popped my solenoids out, tested resistance, perfect. Put on new O-ring &put it all together. Still flashing on overdrive button. Cleaned VSS today, got some relief. Tranni is better. Asfor other problems, Just try not to drive in afternoons. Checked most things, replaced most things, no avail. Part going bad must only be bad when HOT. Is it a relay? Maybe. Changing TPS soon. Probably won't repair it. Feel like a broken wire somewhere. DTC clue? Maybe 212. 116, 167, stuff like that. 172 sometimes. I really hate driving in limp mode. Wish there was a work around. Good day tho, VSS n put dielectric grease on connectors, improved things.

 

You need to desribe what you mean by limp mode, what is the truck doing? Also, what does "maybe 212, 116" mean? Are you getting those codes or not?

 

Yes. Those are codes I've seen over the past couple months as I've tried to diagnose this problem. Limp mode, is what the computer goes into causing me to limp home in the worst possible way, limping and stabling, engine flooded, I believe. if I have to work into the PM. Only fails when its heat soaked so kinda tough to diagnose. I do have my opportunities though.

 

Code 212: Loss of IDM input to EEC

I suspect someone has replaced the Ignition Control Module (ICM) with a gray colored Push-Start version. Your truck needs a black CCD style ICM. Most parts manuals are wrong so that why it most like has a gray ICM.


Code 116: ECT out of self test range 0.3 to 3.7 volts.

Usually caused by not warming up the truck before running the Key On Engine Off (KOEO) or Key On Engine Running (KOER) tests.


Code 167: TPS did not exceed 25% rotation during the Dynamic Response Test.

Operator error, you did not "goose" the throttle at the correct time during the KOER tests.


Code 172: HEGO sensor circuit indicates system lean (right side)

Computer thinks the mixture is lean. Could be an exhaust leak upstream of the O2 sensor.


I highly suggest you stick to the KOEO tests and stored code (Continuous Memory) display. Do not worry about the KOER until all the other codes are resolved.

What you describe does not look like limp mode. I suspect a spark or fuel issue. Spark is the most likely cause. Please confirm if the ICM is gray or black. It should be black.

Please give us more details of "Checked most things, replaced most things"

 

Long story short, I have a 3 week old black "wells" ICM after having the wrong grey one for 5 years.(PO). Changed couple ECTs, few ACTs MAP, HEGO, cap/rotor, idle valve, thinking of a motorcraft TPS, even though seemed to test good cool, also thinking on a dist. 212, I thought is a PIP sensor output signal problem? Overall truck seems a bit possibly a bit sluggish for a 460. 140K miles. Things I haven't done, anything with injectors, removed intake to clean, havent changed dist, coil or EGR (cant disconnect from exhaust tubes without dystroying). Compression is good.

 

IDM is the sign from the ICM/TFI module telling the computer the ignition coil has fired.

It may also be worth pulling out the computer and checking for leaking capacitors.

 

Since Code 212 is in CM, aka stored code, it may be from when the wrong ICM was installed. Clear the CM codes by starting the KOEO tests/CM display then remove the STI jumper when the codes start to flash.

 

Sorry, needed a day. Well it was 99 degrees 2 days ago, it never happened. Yesterday? It was 101, happened again. Often happens when getting off freeway during deceleration. As in yesterday, wouldn't leave the first light. Cranking and pumping. Flooded and back firing. Finally goes if/when pumping gets tach to 1200 when in gear. Got within 8 houses from home, gotta walk, go back 1/2hr later pick up still lagging but operable truck. Checked and changed capacitors last year, checked couple weeks ago. New radio shack caps. Cleared CM, will check for new codes now. (Also tranni seemed to back up as well when truck had problem)

 

When the truck acts up and refuses to start, try pulling the fuel pump relay and see if it starts up well with starting fluid.

 

I mean, tranni seemed to have problems when the other non-running problems occured. Just ran codes, 624, 624, + CM 624 and 624 twice. Seems odd they come twice even after cleared. No others, as had been the case lately. So do you think fuel or spark problems? I have fuel pump pressure gauge, checked few weeks back, all readings normal. I'd do it again now if you think reading when not experiencing problem is fruitful.

 

Sounds like a good one lead head, I'll do that. Its relay# 2 right? I've been checking those relays thinking it was them but switching them around during problems didn't help. But I'll try, I do hear my pump when occurring.

 

Ford never released the info on the black ICM's, the aftermarket just reverse engineeree them. Only a Ford one will do in this instance. Happened on my 97.

 

The idea is to try and figure out of its a fuel/flooding problem, or a spark problem. Pulling the fuel pump relay helps to eliminate the fuel system. It may take a bit of cranking to get all of the fuel pressure out of the rail though.

If the ignition system is fine, pulling the fuel pump relay and shooting some starting fluid down the throttle should result in the engine starting up, running strong for a second or two then dying.

If it's an ignition issue, it won't really respond well to the starting fluid.

 

Well i,be been changing parts this winter. Changing. All to motorcraft, slowly. No problems with low temps of course, except trans which I dutifly ignore now. Long story short , bought a dist. Even know existing worked. Pulled what turned out to be original dist. 22 yrs on that one. Shaft turned real hard. Electronics well looked 22 years old , and used. New one is great. Truck runs completely different. Like a different truck altogether. Mat have solved the elusive hot weather issue. Will update you as info warrants. On a new path now, however.