I was out at my buddy's yesterday goofing off in the truck. I went thru some mud and water and very bumpy roads. The truck ran great, but when I went to go home, I didn't make it 2 miles. It just spontaneously stalled going down a hill and would not restart. It just cranks and cranks. The gas was very low, so we went and got some gas - same thing, and there was plenty of fuel at the schrader. Then we checked for spark - no spark. We went and got a coil off a running truck nearby - still no spark. We ran wire from the battery and got the coil to spark, so we know the coil is good, but once it's all plugged in, it will not spark. It has a code 18 stored in KOEO Keep Alive. I replaced the ICM years ago with a Pertronix, but the old one was still good, so I just put the old one back on and still no go. I cleared the code 18, but it returned after cranking with the good module. Any ideas?

 

Not many people will help you on here if you have a wall of text with no indention or paragraph spacing. Also, a lot of people need to know what motor and transmission you have in your vehicle when you ask for help. I did see you have it listed in your signature, but in your physical post, try to be as descriptive as possible with the problem and what you have. We can help you more with the more help you're going to give us.

Since your motor is an EFI 302, you'll want to pull codes from the computer. Once you pull the codes, post them here if you get any. Mod Edit: Just to clarify... If the computer doesn't detect anything wrong, it will give codes for System Pass (11 or 111 I believe).

You've already got a code 18, which from my searching I found a thread that discusses a code 18.

https://www.ford-trucks.com/forums/6...t-failure.html

How much mud and water did you go through? Did you sink it up to the doors? How much got into the engine bay? Did the engine draw in any water?

How are your electrical connectors? Any of them loose, dirty, muddy, etc?

I'm thinking a new FORD ECM will correct your problem.

If you jump the ECM and it gets spark, then it's probably the ECM.

 

My first inclination is to look for water in the distributor.

 

Bigger question, is the distributor turning? Since it is an 86, I would check the ground plug at the battery where the entire EFI system grounds. It is a two pin plug at the negative terminal, if it got crap up in it, it may have lost the ground. Your ICM is distributor mounted and your EEC is up behind the dash. Do you have any spark when cranking from the coil wire?

 

Very good point about checking to see if the distributor is turning. You could have lost your timing chain.

 

I fixed the problem, but I am not sure exactly what fixed it LOL. I apologize for my lack of courtesy on the forum.... The engine did not suck water, but it has in the past . We were about up to the bottoms of the doors in water, both going slow, and quite fast, too

Anyway, so since at this point it had a known good coil (took off my MSD coil) and a known good ICM I had on the shelf. I figured it had to be the distributor (crank signal). I put a dist in, and since I was thinking it was the crank signal now, I put on the Pertronix ICM. Well, it still didn't fire. Then, I back probed all 6 wires of the ICM, and found a signal wire was not pulsing. So, I put the old ICM off the shelf back on the new dist... Still no fire. Then, I put back on the MSD coil, and viola!

LOL I reached the perfect combination of parts. I read that a bad ICM can take out the coil... Maybe that is what happened. It needed the dist anyway. I had to clean under the cap every few weeks. Pretty sure oil mist was coming up thru. I pulled codes, no KOEO, and only the 44 (removed smog pump) and 25, "Knock not sensed during dynamic test" (Good, right?).

 

A very valid point.

Water is a very good conductor, and it can cause things to go all whoppy-jawed when you start putting it across electrical connections.

Good to know the OP got his issues fixed though.

I would actually hook the smog pump back up to the truck and plumb it back like the factory had it. It doesn't hurt performance in any way, but it does make the air out of the exhaust a little cleaner by helping the oxidation processes (Carbon Monoxide oxidizing to Carbon Dioxide, which is used in photosynthesis by plants to create Oxygen). The EGR increases gas mileage and reduces nitrous oxides as well as lets the motor run cooler too, all without a performance impact. So make sure the EGR stays hooked up too if it isn't already.

Not detecting a knock during a dynamic test? I've never done a test on an OBD-I Ford truck, but I would assume it's talking about the "knock" sensor used to automatically retard the timing if the motor starts "pinging" (A.K.A., dieseling, as a result of incorrect ignition timing, incorrect fuel grade, or some other reason).

The code 25 probably came about when you removed the factory distributor (which to my knowledge, should have the knock sensor mounted to that).

If the knock sensor on your truck doesn't mount to the distributor, I would check it, wherever it may be, and replace it if necessary. The knock sensor keeps your motor running smooth in high-load situations like towing. You can also prevent your truck from "knocking" by using a higher octane gas.

The knock sensor isn't an "absolute necessity", but it helps.