Hey guys...

I have a 1991 F150, 300, which shut off on me three times in just a few minutes while driving down the road. After the third shut off, everything that should have happened when I turn the ignition didn't. Headlights and cargo lights worked, but nothing on the dash. We narrowed it down to a possible problem with the ignition module (correct me if this sounds incorrect). There has been some speculation about the fuel filter, but I don't see this effecting anything electrical in the dash, and it doesn't even try to work when I turn the ignition. Not to mention I've suffered several "fuel filter breakdowns" in the past and this was nothing like that.
I dove into the problem myself, seeing as my mechanic is out of town for a month and I dont have the money to pay for a towing + some expensive mechanic. And it seemed like it would be easy to fix.
However, I found that the ignition module was placed just so that I couldn't reach the two screws that hold it in place on the distributor. I was told it might be necessary to remove the distributor altogether, but I was also told that that is not necessary and I should be able to take the distributor bolt and clamp off, rotate it, and remove the module when it was in a better location.
So, I guess my question number one is: Has anyone changed the ignition module on a similar model vehicle, and if so, how?

Question number two: I removed a bolt from the right, rear side of the distributor, which I thought was the clamp I should have been able to loosen and rotate it. However, I couldn't do that. The "clamp" appears to have a U-shaped metal piece inserted into it, and I can't tell if I'm supposed to be able to remove this metal piece or not... Or, even better, how DO you remove (or rotate) the distributor?

And YES, I have marked everything I can up to this point to ensure the proper reinstallation of the distributor if I need to remove and replace it.
Thank you!

-Belle

 

Please tell us what on the Dash does not work.
Also if there is a small Black with a White stripe wire around the Neg Post of the Battery make sure it is grounded to the Neg (-) post of the Battery.
The other thing that can cause this is a bad body ground.

The TFI module on the Distributor goes bad a lot (does not sound like it in this case) and if you replace it make sure you put a lot of heat sink compound between the TFI module and the Distributor.

 

Nothing at all is working on the dash.
When I turn my ignition key I may as well not be doing anything at all. The radio doesn't work, no dash lights or gauges engage on the dash period.


And, I've said it before I'll say it again, I'm not a mechanic by any means - why would a ground out wire on the battery cancel out everything but the headlights and cargo light, which have nothing to do with start up (or so I thought) and why would the truck restart easily twice, but the third time (after I turned everything completely off to give it time to 'cool off') I'm having the problems mentioned above?

 

First off the TFI module can not do any of this.

Second you have either a bad ground or loss of power to the Ignition Switch.

Either way the problem is in the area of the Battery and Starter Relay.

The small black wire with a white stripe is the ground the EEC uses to operate all of the actuators (Fuel Injectors and a lot of other things). But this wire is not your problem.

You need to clean all of the cable and wire connections at the Starter Relay, Battery and where they go to the body and the engine.
This will more than likely fix your problems.

If it does not check for a bad fuse link in one of the small wires coming off the Starter Relay Battery side. If you can stretch them they are bad.

 

Ooooh.. And I learn a very important lesson about trusting people I don't work with.

Thank you so much.

 

Also your ignition switch could have failed. A haynes manual at any parts store has detailed instructions for removing your switch and testing each key position.

I'll bet a doughnut on that.

Adrianspeeder

 

Just to clarify, turning the key at all does nothing at all, or just when turning it to the RUN position? Does anything happen when turned to the START position? What about when turned to the AUX position?

If it does nothing at all, I suspect Adrianspeeder is correct, and you have a problem with the ignition switch itself.

 

I had almost the same thing happen to me about 2 months ago. After starting my 150 300I6 one morning, I noticed that nothing electric worked (ie. wipers, radio, blower, even the electronic trans. control) except my brake lights and headlights. I later discovered that the key had not fully returned to the ON posistion after being in the START position. An ever so small amount of lube fixed my situation.

Christopher

 

sounds like what happened to me 5 yrs ago (1week before 9/11) so I know when it happened. going down the road @ approx 55 mph and the noticed the tach going nutz, then the engine was missing badly, then it died. had it towed home, called a mechanic that makes house calls and that was the problem, the module by the distributor. I think it is the same thing again, tach going crazy and missing, I will give this a change soon as I have replaced wires, plugs, dist. cap and rotor.

 

[put a lot of heat sink compound between the TFI module]

is that a ground issue or is it to make sure the heat sink works properly?

 

Where the guy go?

Adrianspeeder

 

It is for the heat sink. Without it the TFI module will go bad in a hurry.