mlorsung

Hey all,
Im new here and somewhat new to working on my truck. I have a 1983 f150 explorer 2wd with a 302 under the hood. I have owned the truck for around 3 months now, and in the last month it was getting harder to start, but only periodically, and not particularly predictably. I did notice it seemed worse on wet, cold days, and that sometimes the engine sounded like it might be missing at idle. I looked at the plugs and wires and they seemed old, so i figured replacing those, the cap and rotor was probably a good idea regardless, and might address that problem. While it seems to be better now, I have still had some (though fewer) issues getting her started.

I have checked to make sure im getting fuel by pulling the air cleaner off the carb and watching fuel spray when the accelerator is pressed. I have a strong (new) battery, and the starter doesn't appear to be struggling.

I also ran a test light from the tach side of the coil to the neg side of the battery. With key on, I get no light, and when it cranks and starts the light flashes and goes solid once the engine catches. IF it is not starting, I have found that sometimes I get a solid light on this connection, and last night I moved the harness between the coil and the ICM and the light went out--truck fired up immediately after this. I dont know if this was a fluke or not, because I shut the truck off, checked the light (it was off, truck started fine) and moved the harness around A LOT, without any change in the light...

So according to my very amateur attempts, I am either looking at a short in that harness, a problem with the ICM, or an issue with the coil. My next step seems to be to take off the Ignition Control Module and have it tested. Does this make sense? Can anyone offer other ideas?

Glad to have found this forum, it looks to be a wealth of knowledge

Best,

Michael

mlorsung

so I hope that I posted this in the right forum, I have a little bit of updated information, maybe itll help--maybe not. If I didn't put this initial post in the correct place, please let me know.
So tonight she wouldn't start, I hooked up my test light again to the negative side of the coil and the neg battery, and sure enough the light came on. A few minutes later, it faded of its own accord--does this ring bells for anyone?

Thanks!

Manuellabour247

Sounds like a bad coil. They should be cheap enough to replace without worrying about spending too much money throwing parts at it. If you replaced the other timing components, I would change this also.

Other than that, just check all of the grounds for clean contact. You can remove them and clean the contact points. Then put Die-Electric grease on the contact points. this prevents moisture/air from corroding the connections. You said the cap and rotor were a good idea, but have you replaced them yet? All of this is part of a basic tune up in my opinion. Might also replace the fuel filter while you're at it. Good luck and welcome to the forum.

And yes this is the correct area to post this.

mlorsung

Manuellabour247
Thanks for the input--I appreciate it. I have replaced the cap and rotor, did this when I did the plugs and wires. I apologize if this thread comes off as amateurish--Im fumbling my way through this stuff, but enjoying the learning process none the less. If you don't mind, what about what I described points to the coil rather than the ICM? I'm just curious and trying to learn as much as i can.

Thanks again,

Michael

Manuellabour247

Honestly, it's the only thing you haven't replaced in the spark side of the timing system. Ecm/icm are more expensive. On a Chevy 1 ton my grandpa used to own, he had similar problems. The coil finally went all the way out when we were driving 70 down the highway. Lol. It was a little sketchy.

It's not a "this will fix your problem for sure" answer, but it's a starting point. And it doesn't matter if you sound amateurish. Everybody on here started working on cars in a very similar way. Some of us didn't have Internet to ask for help. Haha. I'm sure there are some other people on here with more technical expertise than me.

mlorsung

Thanks for the response, I replaced the coil this morning and went to start it again just now, no go. same symptom with the test light... When you said to check the grounds, am I just following the negative from the battery back to where it contacts the frame, or is there something else I'm looking for. I know from reading that in a points ignition if I had 12 v on the negative side of the coil it would possibly indicate a problem with the points. My understanding is that the icm handles what the points normally would. Does what I'm describing t hen point to a problem with the icm? I've also read that these usually fail at hot temps, not after a period of sitting... Thanks again for any and all input.

Manuellabour247

The are actually a couple different grounds for the electrical system. Aside from the battery griping going to either your block or the body, you'll have what looks like braided aluminum straps (unless somebody has already replaced them). IIRC there's one from the engine to the frame, and one from the back of the engine to the firewall.

I'll read your message again when I get to work. Also had your starter solenoid been replaced in the past few years and have you treated the starter recently?

mlorsung

Thanks, I'll look for the grounds, I have not tested the starter, can guy describe to me how to do this? The starter solenoid has not been replaced, but the engine does seem to crank ok

Thanks!

Manuellabour247

O'Reilly's or Autozone can test them. You'd have to remove it and take it to them. Before you do though, take a flashlight and look at the starter soldenoid on the side of the starter. Check to make sure the connections are good. Also check the wiring for any corrosion or breaks in the sheathing. Those are some other things to check before you spend any more money or take out the starter.

BTW, sorry for the weird words in the previous post. My phone was using auto text and I wasn't paying attention to every word.

mlorsung

It was the ignition control module--I had a feeling it was heading that direction--I replaced it and its been starting better than ever for a week now. I did the coil anyhow, and it probably needed it. Do I need to replace the capacitor looking thing (condenser?) mounted on the coil as well?

Thanks for all your help--this was relatively painless and enjoyable.

Michael