I want to replace my ICM which is mounted on the distributor. It looks like I will have to remove the distributor to do this. Before I remove the distributor, I want to be sure I can set the timing. For the life of me, I cannot find the timing marks. It is a 1986 F150 302ci with the TFI-IV ignition system. I know sometimes they get covered with grease and dirt, but I don't see where it could be. If I knew I was looking in the right spot I might be able to find it. If someone could tell me where to look, or even better have a picture, I would really appreciate it.

 

It should be on the harmonic balancer. Can you see the timing teeth for setting the timing?

I ran into the same thing on my I-6 and even had a buddy come over and verify I wasn't an idiot not being able to find the mark. Well, I'm still an idiot, but he verified there was no mark on the balancer.

 

I'm tring to find the scale where it shows BTDC and ATDC wit the lines. I can't even find that. I was going to find that scale first and then look for the notch or mark that indicated TDC.

UPDATE: I finally found the scale, but it is on what I think is the harmonic balancer. So if the scale moves, there should be a fixed pointer, right? Here are some pics:



Here is a closeup:



Is the arrow with the "?" the pointer? It doesn't seem very precise. Am I right, that the other arrow points to the scale in degrees on the harmonic balancer?

 

Yes, you are correct about the marks. The round thing is I believe a holder for the factory timing piece that slipped down in and timed the engine on the assembly line.

Look around very closely in that same area for another pointer. Hopefully someone didn't leave it off. It should be positioned for probably 10 degrees BTDC. Check your radiator sticker to make sure. This is the ballpark number that they want the dist set at with the spout connector unplugged. Once the spout is connected back in, the computer takes over and sets the timing automatically. The computer won't let you move the timing unless you take control away from it by unplugging the spout.

If you can't find any other pointer, I would make a place somewhere as a reference. For instance, if you clean that holder off, and the damper marks, and then before you pull the dist, fire it up, unplug the spout, and shoot the timing light down around the holder. Pick a spot and see what number is showing up on the scale, and write that down. Then when you get it back together, unplug the spout and turn the dist till that same mark lines up at the same spot. Then plug the spout back in. The at least you will know the timing is back where it was before you started.

 

Thanks Franklin2, that sounds like a plan. The sticker does say 10* BTDC. And as far as I know the timing is currently correct. It starts and runs good; it's after it warms up that it runs rough part of the time.

 

One thing that is different when it warms up; It goes into closed loop and looks at the oxygen sensor for fueling info. Before it's warmed up, it looks at tables in the computer memory for fueling info.

Keep going down the module road though, they are known to get intermittent and go bad. If it doesn't fix it, you will have a spare which is handy.

 

Thanks, I didn't know that. The codes I pulled lead me to think it's the ignition module. If that doesn't fix it, I'll look into the oxygen sensor.

 

I don't think you have to remove the dist. to replace the module.

 

It would be better if I didn't have to. I was having trouble even getting to the screws on the module though. They are deeply set and I can't actually see them. Do you know if they are Phillips head or something else? I didn't want to bugger up the screws and thought maybe removing the distributor would be better in the long run.