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Your ignition module could be mounted on the side of the distributor, but I didn't think they did that until 1987 with the start of fuel injection on the 4.9. If you go to www.rockauto.com and dial in your vehicle, it shows both types of ignition modules for the 1986 with a 4.9. It only takes a minute and you can see what they both look like.
Follow the wires from the distributor. They should go to the module. There's a pickup coil inside the distributor that triggers the module to create the spark. Could be the module, could be the pickup coil.
But, really, both of these things should be described in your Haynes manual. Rockauto does show the module, with a picture.
BareBones / 88xlt you guys are awesome. Really appreciate the help! Learning a lot already.
Ok, so it looks like mine has the one that comes off the bottom of the distributor. I've attached a picture. Would you guys mind confirming?
And, I promise I looked in my Haynes manual for a good while before posting From what I saw, the only information (and pictures) I could find about the ICM in the Haynes (Ch 5 - Electrical Systems) shows the fender mounted model. Even now, after seeing what I do have, I still don't see the distributor mounted model in the Haynes manual? Not doubting it's in there just couldn't find a reference to it...If it's in one of the wiring diagrams, that may be why I overlooked it. I'm a little embarrassed to admit I have no idea how to read those.
At any rate, very appreciative that you guys steered me to the right spot. And what a great resource Rock Auto is! Thanks for that as well.
Yes that is it. It is very common for those to go dead when they are mounted there.
You need a special tool to remove and reinstall those. It is a skinny nose socket of sorts. A regular deep socket just doesn't have a skinny enough nose. Hopefully you can find the special tool at a local auto parts store.
Which edition of Haynes do you have? Read the caption of the pic I posted earlier to ID it by cover color, and last page number. All editions have the diagnostic procedure for the distributor-mounted TFI-IV (DI) system.
88xlt, thanks for heads up and tonight, I found the tool I need for it via Rock Auto. I went ahead and ordered the distributor wrench too b/c it looks like I'll need to loosen the distributor a bit to fully get to the ICM. Do you agree? I read to "mark" where my distributor is priot to moving it as to not throw off the timing...no clue what that means but seems easy enough to mark
Steve83, yes sir I got the red cover Haynes 80-91 manual that you recommended. I must've looked over the diagnostic procedure you referenced. I actually left the manual at my office today so I don't have in front of me to check right now.
I went ahead and ordered another coil too just to be safe b/c I took the coil off last night thinking that would be my problem. If nothing else, I'll at least have a backup. I can tell the coil that was on it hasn't been replaced in a long time.
With that, I'll wait a couple days for everything to come in and I'll give it a shot at replacing and we'll see what happens! I'll report back. Again, thanks very much to all of you guys for your input and wisdom!
I don't think you will have to loosen the distributor in any way. I have changed that ignition module on my 1988, with that engine, a few times and never had to loosen the distributor for that job.
In the unlikely advent that you would have to rotate the distributor, yes you would want to mark the distributor bottom in relation to the engine block. That would get you very close to back in time, where you should probably recheck the timing with a timing light and adjust the timing by slightly again rotating the distributor if necessary.
NOTE: when you go to install the new ignition module be sure to install the special heat sink grease on the back where it goes against the distributor. Hopefully a small packet will come in the box with your new module, if not you can purchase it locally.
Any more questions just ask and I will try to answer them.
I thought I still had that edition, but it's not in my Haynes pile... So look on p.5-1 in the TOC for "TFI-IV or DI system - checks". In the '80-96 red edition, it's Sec.7, which begins on p.5-10.
Originally Posted by 88xlt
I don't think you will have to loosen the distributor in any way.
It depends how the distributor was stabbed last time. If it's a tooth off, the distributor body will be rotated differently, which can make the ICM screws inaccessible.
Alright gents I'm putting the new ICM and a new coil on this weekend. Had hoped to start on it yesterday but FedEx guy was a day behind.
My particular ICM (Motorcraft) did NOT come with the heat grease which means another run to the auto parts store before I can get started. Only have an hour or so today to work on it. Will definitely let you guys know the outcome...
02-19-2018, 10:25 PM
From what I saw, the only information (and pictures) I could find about the ICM in the Haynes (Ch 5 - Electrical Systems) shows the fender mounted model. Even now, after seeing what I do have, I still don't see the distributor mounted model in the Haynes manual? Not doubting it's in there just couldn't find a reference to it...If it's in one of the wiring diagrams, that may be why I overlooked it. I'm a little embarrassed to admit I have no idea how to read those.
So look on p.5-1 in the TOC for "TFI-IV or DI system - checks". In the '80-96 red edition, it's Sec.7, which begins on p.5-10.It depends how the distributor was stabbed last time. If it's a tooth off, the distributor body will be rotated differently, which can make the ICM screws inaccessible.
