What the...?

[AJBH]

So the old girl ran good all summer, worked hard, never complained. I'm getting ready for winter, putting the sander and the plow on, and all of a sudden she starts acting up. Now, she's getting on in years... 86 f-250, 460ci, but man, she's all there. I keep her local, too thirsty for out of town. She started to just shut off while I'm driving, bam, just off. No sputter, just silence. I wait a minute, starts right up like nothing wrong. Only now doing it more often, today several times, off, start up runs great for 10secs, then silence. Takes a few minutes to restart, and all over again. Good fuel and pressure, I have a booster on the fuel line. As quick as the shut off is it seems like electric, either loose connection, a short I cant find, smell or hear, or something starting to go. My coil is still getting power even after the shut down, so that is not it. Can the coil itself do something like this? The ICM? Who's got an idea, it's gonna snow any day now....

 

[smokey]

The tfi will do this when they start going bad.

 

[AJBH]

Smokey, what is the TFI

 

[Fellro]

Thin Film Ignition module I think is what it stands for, but it is the small ignition module, but when I looked it up for the other thread, it appears that both the Duraspark II and TFI were available in that year... I am thinking that the 460 was injected, which would then dictate the TFI.

 

[AJBH]

Fellro, my rig is carbed, Edelbrock. As I said in my other thread, there is nothing on my distributor. I have a question about coils. When I bought the truck years ago there was some fancy coil on it, but it is long gone. I run a stock coil now. Are there any advantages to running a hot coil?

 

[Fellro]

If it is carbed, then the DS II module would be the culprit, which is also fender well mounted. It is a square box, about 2" thick, 4" x 4" square. It will have 2 round plugs from it. If it has a round coil, it definitely is a DS II module.

Hotter coils give a bit hotter spark, which helps get the combustion process going a bit better is why they get put on quite often.

 

[AJBH]

I think you have it pegged, Im going to install the new one today, will post how it goes. Finally put a few pics up.

 

[AJBH]

So I put in the new ICM, truck popped right off, ran good. I have not had time to run it very long since, so time will tell. I think the one I replaced was only 2 years old...

 

[smokey]

Glad you got it going. Haven't been on much. Roger knows his stuff. Sorry I thought your truck was fuel injected.

 

[Fellro]

The aftermarket DS II boxes aren't known to be real long lived.... They are notorious for playing games like you just experienced. I had one that would just shut me off going down the road, wait about 10-15 minutes, fire up and head on like nothing was wrong...

 

[AJBH]

Well anyway, We are back on the road again, thanks for all the input. Up here in Vermont we will be getting snow anyday now, and it last for 6 months. When the truck runs good it makes my life a whole lot easier. I will keep my eyes out for a Ford DS II mod, maybe I will get more life out of one of those...

 

[marciawillie]

in case that idea doesn't work, check the valve that changes from the front to rear tank or vice-versa.. mines the 6.9 diesel, but had the same issue with it; after numerous times stopping dead on the side of the road, and having to have it trucked home a few times i went to using just the back tank and eliminated that valve, and have had no problems with the fuel since.. of course now there are problems with the rear tail and turn signals, have nothing if the headlights are on, have brakelights when they're off.. replaced the headlight switch, and it made no difference..

 

[fatherdoug]

Might also want to take a look at the dimmer switch, if it is located on the floor.