Last week I replaced the ICM on an 86 Bronco, 302 EFI. Well it went out again, I replaced it and still didn't run.

So here is what happened and what I done. This is with the first new ICM, I replaced it last Sunday, and I drove it most of the day with out any problems. On Monday I drove it for about 45 minutes and all was well. Then on Tuesday I decided to clean the engine so I used Gunk and power washed it. I tried the steer clear of the distributor and electrical stuff. Well I guess I didn't do such a good job. After cleaning it started and ran about 3-5 minutes and quit. So I stopped messing with it and just let it sit. Then on Wednesday after work I tried starting it. It ran fine, took it for a drive to get gas and parked it. On Thursday I tried starting it and it almost started...It was like I let off the key just as it was starting. So I tried restarting and nothing. Now all this is with the first new ICM ($40.00 from Autozone).

So I though I may have damaged it with water/gunk during cleaning, so I replace it again (now #2), still no start. Not getting any spark.

I started troubleshooting and tested the coil using a test light. Light was bright and flashed good according to the book. As I was testing I had the coil wire off and it started sparing all over the place. So I put the coil wire on and it started up and ran good for about 2 minutes. The I tested coil again with light, now the light was dim, I didn't have a Volt meter at the time and couln't OHM the coil so I just replaced it and still no start. I went throught all the testing and everyting pointed to the ICM being bad. I took it out and went to autozone and had it tested and it failed three checks.

Now my question is..what could be buring thses things out, or am I getting what I pay for? The ICM at Checker is $90.00 and it is $40.00 at autozone.

One more stupid question...my hanes manual keeps saying to check for 3.0 thru 8.3 Volts AC at various spots. Shouldn't it be VDC that I am checking for?

Any help would be greatly.

Thank You!!!

 

First, disregard the comment in my signature because I read somewhere that Ford did not go to the CCD system until the 90's.

Pull codes, KOEO and CM and report back here.

You are probably on the right track that cleaning the engine started it all.

My suggestions...Dry out the distributor cap inside. Clean the connections with electrical cleaner, blow dry and apply dielectric grease at the ICM, distributor and coil. Clean back of the ICM and liberally apply a semiconductor heat disapating compound from Radio Shack as it is better than dielectric grease, especially if the ICM is distributor mounted.

Check grounds...disassemble and see if the stud is turning in the fender next to the battery. I had to make a new one. Other grounds are next to the code pulling conector, firewall to engine, and radiator bracket.

Also consider the stator in the distributor as it has about the same life as the ICM and behaves similar to ICM when it starts to fail. Cleaning and drying the connectors may help. Near distributor, the bolt-together zillion wire one on the driver's fenderwell, and the one on the PCM.

I don't have an answer why the ICM is burning out or the DC-AC question but I'm sure others will come along when they get through working on their Broncos. I do have two almost new gray Motorcraft ICM, different part numbers, used only a few days that would not work for me as I needed a black one for my '94.

 

b4hntn,

I went out and replaced the ICM again and it started right up. I also cleaned the connectors.

Well I took it for a test drive and sure enough it quit on me again. I towed it home and pulled the codes.

The best I could tell I got a code 14 then 18 and then 14 and 18 again. I think I am reading them right.

We can put a man on the moon and bring him back again, you think we could create a code reader that will tell you the code instead of having to know mores code.

The code book I have says:
Code 14, The Electronic Control Assembly (ECU has detected an intermittenet loss of Profile Ignition Pick-up (PIP) signal during the last operation.
Code 18, Loss of TACH signal to Electronic Control Assembly.

The book tells me what they are but not how to repair. Other than replacing the ICM for the 4th time...I don't know what to do.

Any guidance would be appreicated.

THANK YOU!!

 

Your code 14 soulds like the 121 on mine I fought for about a year. Four ICM, three distributors, completely opened harness and found no bad wire until I found the previously mentioned bad ground on fender next to battery. When the battery cable was replaced the stud just turned in the fender and the wire eye lugs were also loose and Pep Boys left it that way for the previous owner. The reliability improved and PIP code left after fixing the grounds and getting the correct module.

I have a thought and I hope someone can correct me if I am wrong. My 94 does not have a resistor in the harness but yours might. I THINK I remember the resistor ruduces the ICM voltage for run but is bypassed for start. You might check Haynes wiring diagram for color to check and find the wire the risistor is in and ohm both ends to test the resistance. The resistor may have been cracked of just burned out or intermittent.

Summary,
Grounds, connections, resistor, distributor stator (or PIP). If your ICM is mounted on the distributor the Radio Shack compound to dissipate the heat may help. I don't remember what year it was moved to the fender area and set in a heat sink.

I have a great litle code reader which I carry in the console. Black and yellow, costs under $40 and has been used a hundred times due to intermittent stalling.

Good luck and maybe a professional will be along to edit this.

 

I went through a simular problem. First off did you get a Black or Grey ICM?

I believe you need a black one. I can remember why so I will have to do some research and get back to you.

 

Ok! I remember now! Somebody on this web site told me about the Black and Grey ICMs. So I checked it out and he was right.

The Auto parts store gave me a Grey one which only worked for a while. So I did a part search on line and sure enough the ICMs I found did not match the the factory replacement number. (My old ICM Motorcraft #F1SF-12A297-C1A)
I looked this up at Summit Racing. None of there replacement ICMs listed for my Bronco replaced the Motocraft Part and they where all Grey.

Next I did a search for a 96 Ford Probe ICM. Sure enough the replacement ICM matched my old Motocraft ICM and was Black just like the guy told me!

I would recommend doing a part search at NAPA Auto parts and see if you can do a cross refrence part search by part number! First get the factory number off the orginal part.

 

Code 14 = PIP signal intermittent... the early PIP (Profile Ignition Pickup) sensors were inherently weak and prone to failure. If you keep going through ICM's it stands to reason that the problem is NOT the ICM but something attached TO it like oh, say the PIP sensor. The PCM doesn't generate this code arbitrarily. The procedure for tracing down faulty wiring to the ICM particularly the PIP sensor link is tedious and requires some electrical know-how. If you need a detailed description, let me know. Replacing the PIP sensor requires opening the distributor and removing both the rotor and the tone ring. BE extremely careful when removing the tone ring... if it gets bent or damaged it cannot be re-used. Once the ring is out the PIP sensor can be unbolted and disconnected from the wiring harness. Inspect the PIP sensor for cracks in the plastic housing. If there are ANY or any of the wires are damaged, replacement is necessary. Replacement is the reverse of removal.

The PIP sensor is an inductive device so make absolutely certain there is no radio frequency or errant magnetic field being generated anywhere near it.

 

b4hntn, rudedogii and greystreak92,

Well I think I finally got it fixed. I hope anyway.

I replace the PIP Stator and cleaned up the grounds.Then it started right up and ran good. Now, it ran good tonight...been there before. I'll have to see what the next couple of days brings.

As for the color of the ICM, I installed a grey one because thats what was in there. I think the instruction sheet said I could use a grey one if a black one was installed but can't use a black if a grey one was installed. I think anyway. I looked for the instruction sheet but couldn't find it. At any rate is seems to be working, at least for now.

I don't know how to send rep points, but know this, you guys deserve them in my eyes.

Thanks again for your help!!!

 

That sounds good so far! If that dont work it could be the stator in the distributor.
I would recomend buying a rebuilt distributor because you get the whole thing. Its like plug in play.

 

Congratulations reaching the cautiously optomistic point! Next, I would clear the codes then check the codes from continuous memory in a few days and hopefully get more confident the intermittent beast is gone.

On my '94 the original ICM was black and I tried two grays before returning to black.

I carry a code reader, spare black ICM, tool, heat compound and die-electric grease in the console. The last time it died was at 2:00 AM just leaving on a hunting trip 550 miles across Texas. I immediately pulled codes and all were clear. Poured in some Heet and Sta-Bil and it started right up and it has been fine every sense. If I did not have the code reader I would not have guessed a fuel water condensation issue and would have turned around and missed a great hunt. The Bronco sits a week or two quite often so I am now a regular Sta-bil user.

 

Glad to hear things appear better. I know the cautiously optimistic stage myself but it really does feel good when the ol' girl just up and runs right without that tightness in your gut every time you head out in a truck that has been sketchy. Best of luck with it. Let us know if the issue returns.