I have a 1986 F150 5.0L/302ci. It has been running rough part of the time. The first time I ran the codes I did it wrong and didn't get them all. I think I've done it right now. I recorded the procedure and put it on youtube: YouTube - Checking codes on 1986 F150 5.0L EFI . I would appreciate a second look from someone who has done this before to make sure I have the right codes.

If I read these codes right, I initially get "11" twice, meaning the EEC is ok. Then I get the continuous codes "14" (PIP failure) and "18" (loss of IDM input to processor/SPOUT circuit grounded). Running, I get code "44" (thermactor air system inoperative).

I haven't done work on EFI before I got this truck, so I'm feeling a little overwhelmed. From what I've read, people say if the PIP is bad the engine won't run. Mine runs. Looking in my Haynes book, it seems to lead me to think the ICM is bad--this one is mounted on the distributor. On this engine, can I remove the ICM and check it without removing the distrbutor? If I have to remove the distributor, how big of a deal is that? I know to scribe a line and not crank the engine.

With the "44" code, would the thermactor system cause rough running?

So far all I've done was check to make sure the ICM connector was not loose, and I didn't see any damaged wires.

I would appreciate any suggestions on what to do next, and also know if I interpreted the codes correctly.

 

The second set of codes are the memory codes, codes that have been stored at some time or the other. I would disconnect the battery for a minute or so, and then check the codes again. You will probably get 11's with no memory codes. You can then drive it for awhile and check the codes again, and see if your memory codes have come back. If you get the same memory codes, I would try a new dist module first, and then check the wiring again, and follow it along till it runs under the dash, and also unplug and check the main computer plug.

The Thermactor code is just the air pump. Probably someone had taken the belt off, or taken it off all together. It's something I would not worry about.

 

Thanks for the help. Less than two weeks ago I had the battery disconnected when I replaced the heater core, so the codes should be new. It makes sense that it's the ignition module--it runs better cold than after being driven 20 minutes or so. I know there is a heat sink in that module, so heat is probably an issue with it.

I can get a cheaper module for about $38 locally that has a "limited lifetime warranty" or I can get an actual Motorcraft module from RockAuto.com for $118. The Motorcraft has a 12 month/12,000 mile warranty. Do you think the Motorcraft module is worth all that extra money? I plan on keeping this truck for several years and want it to be reliable, but I don't want to just throw money away.

 

I replaced the module on my 84 300-6 with a Wells unit, and it worked great for years. If the module is bolted to the dizzy, make sure you use enough heat transfer grease on it so it'll survive.
Before you replace it, have AutoZone test it several times to see if it's actually bad. Might save you some money.
All that said, I'd still prefer Motorcraft. So much so that the new module I bought for my DS II swap sits in the box and a used Motorcraft unit is bolted to the fender.

 

It's hard to diagnose the module on a tester if it's a heat related failure.