This is a contiune of this (http://www.pirate4x4.com/forum/showthread.php?t=601177) thread..

Tested the previously mentioned TFI modules today, both tested good, everything checks out, but the distribuor doesn't signal the coil for some reason..

Pinned out all wires in the harness back to the ECM, all fine, even passed a wiggle test

Tested TFI,
GND to PIP in, around 600 ohms, pass
PIP power to PIP in, 1001 ohms, pass
PIP oiwer to TFI power, 100 ohms, pass
GND to ign GND, .1 ohms, pass
PIP in to PIP, 100 ohms, pass

Then reinstalled the TFI, plugged in harness, and back checked everything.
distrubitor ground, good
power to TFI, 12.5 volts
power to TFI while cranking 10 volts (8-10 is spec)
PIP output, 4.5 volts (spec is 3-6 volts)
spout, 4.7 volts (spec is 3-6 volts)

Now, acording to all that, and what it says in the ford fuel injection manual, the TFI and the pickup in the distributor are both good.

However, the lack or signal to the coil leaves me to believe the hall effect sensor is bad. But being that there IS a PIP signal, it must be good? correct?

Testing the input to the coil, power side has battery voltage, negitive side has zero volts with the key on, and zero when cranking(should be an AC square wave, from ground to battery voltage, correct?) Test light does not blink when attached to it..

Anyone have any ideas? or I assume someone here has to know more than I do about this stuff..

the hall effect sensor may be producing a PIP but it may not be a "correct" signal

i would think the TFI is melting because of a wiring problem - could be intermitten - i have seen a bad coil send high voltage back to the tfi and melt it.

check to make sure the voltage / resistance is right when cranking (edit - forgot to read again )
http://i106.photobucket.com/albums/m272/f250rollinon37s/42295236.gif

http://i106.photobucket.com/albums/m272/f250rollinon37s/42308329.gif

TEST 5, STATOR


Remove distributor from engine, then the TFI module from distributor.
Measure resistance values between module terminals as follows:
GND and PIP-in, resistance should be greater than 500 ohms.
PIP PWR and PIP-in, resistance should be less than 2000 ohms.
PIP PWR and TFI PWR, resistance should be less than 200 ohms.
GND and IGN GND, resistance should be less than 2 ohms.
PIP-in and PIP, resistance should be less than 200 ohms.
If readings obtained are as specified, replace stator.
If readings are not as specified, replace TFI.

i would say try to replace the tfi again - but use a diffrent coil.

hope this helps- as its hard to work on rigs over the computer :)

TFI modules can check-out fine when cold. Heat them up and they fail.

TFI modules can check-out fine when cold. Heat them up and they fail.

yup. except his doesnt have time to get warm. :D

I should have a couple spare stators if you want to try one.

I had the hall sensor go bad on mine and it would just randomly die, no spark, then sometimes it would just start working again. That was on a brand new autozone one, which i don't recommend getting it from them ever again.

The reason i was replacing mine was, because i was trying to pinpoint a TFI killing problem. Which i later found out someone test the wires at the TFI mdule with an itty bitty pin, and then later got corroded worse.

The hall sensor is cheap and easy to repalce, easy to remove it from the problem. I later ditched it all and went back to DSII and a carb, because my harness was so fubared

thanks for the suggestions, I'll try a few more things today, and go from there.

New hall sensor didn't do it... even swapped in another TFI just for piece of mind.. lol.. still no dice...

Retraced all wires again, still nothing..

ecm ? but during start up the module ( TFI ) is suposed to control the spark and timing , after the engine starts the ecm modifys and tunes - hmmmmmmm -
dumb question
is the engine light on when the key is on ? good power and ground to the ecm ? i can get you a diagram / pin location if you like

yeah, cel is on when the key is on. I even pulled codes, lots of them for unhooked smog shit, but thats it..

I WILL fix this fucker, and I KNOW it's something simple..

did you try to run it with the timing pill / plug out ?

actualy, no.. I don't see how it would change anything, but then again, I don't see how it doesn't just start up in the first place... lol

I'll add that to the list of things to try in the morning..

well.. today it ran.. for a while...

I checked a few more things.. and decided to check out the coil(rather then just trying a spare like I had before)

after the pulling the coil off, I found the neg. side terminal was bent over at a 90 degree angle, which would explain not getting the voltage pulsation, because that side wasn't connected to the coil, resulting in it always reading zero volts... I also found the coil was bad..

Now this doesn't explain why it didn't start on my spare coil, 3 days ago.. lol but it WAS forward progress..

SO, after making some good jumper wires, I hooked up my old duraspark coil, and fired up... Ran for 3 minutes, and flat out died.. No spark.
Thinking that perhaps the DS coil couldn't handle the 12 volts from efi, I went and got another TFI coil from a buddy.. Put it in, and NOTHING.. Instinctly, I changed the TFI, and it fired up.... for a minute, and died.. Coil was smoked..

But yet, both TFI's stil TEST good..

Right now, my only guess, is that some short is burning the coil? or possibly something is amiss with the charging system, overcharging, and wreaking havoc?

it sounds like a short... ive seen charging systems run at 15 volts and not blow them... :confused: i dunno. i can see it having a short sometimes, just enough to pop them...:confused:

good luck man.