If you want the whole story from the beginning, you can read it here:
https://www.ford-trucks.com/forums/5...-question.html

If you just want the nuts and bolts...
My truck died with little warning. The symptoms resembled those of a bad CPS. I replaced the CPS, and it still wouldn't fire (cranks fine, no ignition).

The saga continues...

I had a diesel mechanic buddy come by to hook my truck up to his 5-star diagnostic tester. He says that the IDM (Injector Driver Module) is shot. The read-out that he got from his tester, combined with the fact that my injectors made no buzzing noise during the test led him to this conclusion. (when he hooked the tester to his PSD, you could hear all eight injectors buzz at once, followed by each individual injector buzz in sequence). He added that if it were an under-valve-cover-harness problem, the injector read-out on his tester would show bad on the affected side, but mine was showing mixed bad injectors (something about low and high voltage or being stuck open, or something....I really didn't understand the whole thing).

I trust this guy, but before I shell out $550 for a new IDM, I just wanted to get some experienced feed-back from the masses.

I would also like to explore the possibility of replacing my IDM with one from a low mileage salvaged truck. Is this a viable option, or is out-of-the-box replacement the way to go?

He warned me that changing the IDM can be a fairly dangerous job. He said the IDM is basically a box full of capacitors that convert 12 volt into 220 volt to fire the injectors. I'm pretty handy with a wrench, but is this something better left to a mechanic?

If you have anything to add, please do so.

 

It's only 120 volts, not 220.

People change them all the time without getting zapped. There shouldn't be any "residual charge" in them.

A used one will work as well as a new one, assuming it checks out electrically.

Pop

 

It converts the voltage to 110 VDC..read the codes the codes will direct you to the problem, If he is a good buddy have him switch IDMs with you and see if that repairs the problem..

The IDMs fail, but not very common failure.

Yes, i have bought several IDMS from salvage trucks..and have modded several as well...

 

My mistake. That's what the mechanic said as well. I hit the wrong key.

Thanks for the feed-back.

 

Have you checked the IDM power relay.

 

you can usually get an idm on ebay between $200-$300

 

Is there a way I can check this myself?
I don't have a tester.

 

Swap it with the blower motor relay just behind it.

 

Not to get off topic, but how would you mod an IDM?

By mod, do you mean rebuild?

 

Swapped the IDM relay with the blower motor relay.
No luck.

The blower still works, and the truck wont start.

 

That rules out the relay.

The IDM Mod (Joe Servo) replaces a resistor in the IDM upping the voltage and causes the injectors to fire quiker.

 

Indeed, and it was a good thing to rule out.

Any other ideas, or am I stuck buying an IDM?

 

If you want to save a little money of a salvage try www.autocomputersupply.com

If the IDM is getting power but not outputting (no buzz at all) and the PCM checks out OK (successful KOEO) then thats what it sounds like it is pointing to.

 

Found an IDM from a salvaged low mileage 2001 PSD for $150. The truck was totaled from a severe rear-end collision and bent frame, but the guy says the engine still runs just fine.

I'll pick it up tomorrow, and hope to get it installed tomorrow evening.
I'll keep everyone posted. Thanks for all the advice and help.

 

Picked up the IDM today, but it was raining. I'm not too keen on the idea of laying on the wet ground and messing with a metal box full of capacitors.


Hopefully Mother Nature will go easy on me tomorrow morning, and I can get 'er installed.

Wish me luck.