got and 88 f150 with the 4.9 that just died on me. It has power at the coil, but the coil wont ground to spark (I assume).

I traced it back to the ICM (dizzy mounted) and all wires checked out except the yellow one (second one down from top.) When I hit it with the test light I just get an arcing sound comming out of the dizzy/ICM area:confused: What does this wire go to?

http://i106.photobucket.com/albums/m272/f250rollinon37s/42307170ii.gif



yellow is the ECM -

is this the same truck you had problems with before??

easy fix replace your tfi modual and you'll be ready to go again

is this the same truck you had problems with before??

yes :mad: I'm having more and more reason to believe its the TFI mod. just wanted more opinions before I replaced it.
Was hoping to keep it on the cheap, so I dont want the replacment diagnosis.

yellow is the ECM -

Wonder how much (if any) damage was done by using a test light on that wire? A test light really shouldn't be used when working on electronic circuits.

Yellow returns to the EEC. I agree that it is probably your TFI module that shot craps. Did it suddenly stop running, or did it deteriorate then lose spark?

Slowly died both times. Almost like runnig out of gas or such. But it consecutivly died. Not rev up, down, up down then die. It just ever so slowly died.

It most definately sounds like your TFI module went out. Go buy new one (about $30 with a lifetime warranty) and replace yours. The thing to consider is why did it go out in the first place- but a new module will most likely fix your problem.

Slowly died both times. Almost like runnig out of gas or such. But it consecutivly died. Not rev up, down, up down then die. It just ever so slowly died.

Went out and got a tfi (40 bucks) went to put it in and cant get the dizzy out. Anyone know what holds it in for screws? I cant get my fat fawking head in there to see.

The distributor doesn't need to come out. The TFI module is attached by two screws on the face of the module. Disconnect the wiring harness from the TFI and remove the two phillips head screws. The TFI will just pull straight down, and out. To install, place the heat shield on the back of the TFI, then insert it back up and into the face of the distributor. Put the screws back in, plug in the module and fire it up!

Let us know if it works.

Went out and got a tfi (40 bucks) went to put it in and cant get the dizzy out. Anyone know what holds it in for screws? I cant get my fat fawking head in there to see.

mines held in with either two 9/32's or 3/16's screws. Need to go get a longer socket and try again tomorrow after work.

Sooo I go tthe new TFI on. Wired the fuel pumps direct, and turned her over while my buddy turned the dizzy. Long story short it STILL wont start, but the dizzy knocked him on his ass :laughing:
And more thoughts? Going to try it again tonight, I dont think it is anywhere near close to timed right.

It fired. Buddy had the dizzy 180* off:shaking:

It most definately sounds like your TFI module went out. Go buy new one (about $30 with a lifetime warranty) and replace yours.

Yup, and carry a spare in the glovebox and your set. I friggin hate electrical gremlins :spam:

Keeps blowing the fawk out of fuel pump relays too :shaking:
So I set it up to a switch :grinpimp:

I hear ya on the ecletrics pro. If I could find an old carb'd truck up here worth building up for under 3k then I'd be all over it. Fuck my 88 has the cab welded to the frame and a piece of c-channel for the radiator core support. :shaking:

so did you figure out its a 5.5mm head? lol. we replace em all the time. infact, we did one on a 90 van today... efi rocks once you find all the bugs and fix them all at the same time...

about the fuel pump, id check your wiring between the relay and the pump, make sure it doesnt have crazy resistance, and if thats all cool, your pump may be goin out. seen it before... it pulls too much and melts shit. that and check your fuel pump shut off switch... (you may have already, i just browsed quick over this)...

good luck.:homer:

Oh , and it is never safe to use a test light on a computer controled circuit. Use a DVOM ( volt meter ) when they light up, or dont, they compleat a circuit and can damage eather the ECM or components.


look - no ------- in my answer - im trying :flipoff2:

5.5mm or 7/32 :homer:

I'll just run the switch. My woman says it's rigged but its only a mud truck for christ sake.

I Dont care for EFI, except for dd/ show trucks, and ones that would see NASTY angles. For what I'm doing an old carb'd bitch would be fine.

yeah im still runnin the switched fuel pump on my DD and its been that way for 2 years. :D no one can figure out how to start it... ive seen guys at my work push it cuz they couldnt get it started when i GAVE them my keys...:shaking:

i could, isnt that why you threatened to take your battery / ECM with you when you went out of town ????:flipoff2::flipoff2::flipoff2:

thats because you wanted to wheel my truck with a guy who has rockwells and 49s. :shaking: while i was in LA. you basterd. lol.

Glad to hear you got it running!