Electrical - I'm stumped!

[Poolio]

I've been having intermittent problems with my GW ever since I did the TFI upgrade. She'll idle fine, but will sometimes hesitate/stumble under load. Sometimes, without any warning, she'll just DIE. No spark for at least several hours afterward. Then, after she sits dead for awhile, she'll start right back up. But then, eventually, she'll die again without warning. Sometimes she'll stay dead for days. Had to tow her home last time.

Thing is, I'll take her to my local mechanic and he can't reproduce the "dying" problem. She'll run fine for him!!!

I've searched the forum numerous times and based on others' suggestions, I've REPLACED the following:
- Coil (twice)
- Ignition box (thrice)
- Starter solenoid
- Distributor pickup coil
- Ignition switch on the steering column
- Fuel filter

Still has the same problem. She'll hesitate/stumble under load and die without warning. I've now replaced the TFI coil with a new OEM-style coil. I've retained the upgraded plug wires, dizzy cap and rotor.

The only thing my mechanic has been able to tell me is that once he hooked up an oscilloscope to the engine and said when she "stumbled", she would only be running on half her cylinders. But before he could try to pinpoint the problem, she fixed herself.

This last time she was in the shop, the mechanic checked the resistor wire and said it was fine.

ANY IDEAS?? Please help! Winter approacheth...

[TexasJ10]

I grew up in Iowa and don't envy you going through the winters.

I had a similar problem a few years ago with the stock ignition. It turned out I had a corroded connection where the wire from the starter soleniod connects to the fusible link inside the wiring harness. I unwrapped all the tape that someone had put on it and the wire practically fell off. I soldered the connection together and sealed the connection with heat shrink tubing and have never had a problem since. It may have been that this connection was disturbed when you installed the TFI. Does everything go dead at once when you have this problem? All power routes through the fusible link. Also check your gound connections closely, particularly the engine ground that is attached at the coil bracket. Your ground cable terminal may have pulled loose as well when the TFI was installed.

[Lindel]

Let me ask a question. Do you have a gold, or brass colored metal cylinder on the input to the carb?? If you do, remove it, and see if you can move air through it. That's one of Ford favorite type of fuel filters, and the media will harden (quickly), and cause the vehicle to "run out of gas". If you do have one, you can puncture the media, or remove it, and get the correct sized adapter for the fuel hose.

[Lindel]

It could possibly be the horseshoe connector for the coil has corroded connectors, too.

[Poolio]

Yes, everything goes dead at once. No warning.

I've unwrapped all the wires involved here to expose the fusible links, and everything looks fine. I've thought about re-wiring everything, but that's a LAST RESORT.

Lindel, fuel is not really an issue - I'm getting plenty. I do know that during these "down times" when she won't start, I get absolutely no spark.

I've also pulled the coil's horseshoe connector and sanded the connections. They're good.

I'll have to check the ground wire at the coil bracket tomorrow morning...

Any other thoughts other than buying a LOT of wire??

[gsmikie]

i get the same problem on alot of the cars i get what i do is take a day and undo all the elec connectors and spray them with elec contact cleaner and then i fill the connectors with die elec grease i do all the pull apart connectors in cluding the fire wall bulk head connector then i put them back together and in 99% of most it fixes the problem

[Lindel]

You say you still have the resistor wire going to the positive side of the coil? If you do, you can take that off, and apply a full 12v to the TFI coil. It'll start easier, and run better.

That might be your problem, give it a try.