I've been posting on here hoping for shots in the dark as to why my 94 F250 with a 460 keeps dying and restarting at random intermittent times. One particular answer was a bad PIP sensor, and while I don't want to buy another new distributor, it may be the issue. This weekend I was test driving it and it died at speed in 5th gear (its a manual). Even though the engine woulda been turning about 1200 rpms from the wheels, the tach read 0. Am I on the right track and how definitive is the diagnosis? And what quality distributors could you guys recommend? Thanks for the help.

 

I recommend a new Carquest distributor, because they are heat tested, re manufactures are not...130.00 bucks, and you keep your core

 

I have spent hours on the web trying to find a bench test for the pip sensor. Is there anyone that could PLEASE explain how to bench test a pip sensor. and it not be in the dizzy. I have read and read this same problem with so many people. I am having the same problem. I have put two new ones in the dizzy, still no fire. Have replaced EVERYTHING in ignition except PCM. Still no fire. Have checked all parts by book and other peoples trucks. PLEASE, PLEASE, PLEASE can anyone tell us how to bench test a PIP sensor to tell if it is good. SUBFORD ? SLIP FORD MAN ? Thankx man.

 

I would start a thread on this, but i just joined this and not real sure how to do it. If anyone could tell me how to start my own thread it would be great, because i have did EVERYTHING to this truck, and still cannot get it to fire. BTW, Spent hours on FordFuelInjection, Very good site, and easyautodiagnostics.com, very easy checks on no start, but i did all that, two pip sensors, still no trigger signal, I cannot find a bench test for the pip. Thankx 1994 4.9L paperweight. lol

 

There is no "bench test" for a PIP sensor that I know of. My buddy Joel5.0 has a great writeup for testing the TFI AND PIP sensor in vehicle here: SBFTech.com TFI Module/Hall Sensor Testing Procedure

Several previous posts are starting to lead me to advising you to remove the connector to the PCM if the PIP signal is not in range of the stated values.

The PIP signal goes to the PCM as well as the TFI module. Any one of those can load down the signal.

This cut from my 1993 Ford Service Manual:

How The Circuit Works


The Distributor contains no centrifugal or vacuum advance mechanisms. All spark advance/retard is accomplished electronically by the Powertrain Control Module (PCM).

During engine cranking (and after the engine starts), a Hall Effect Switch inside the Distributor assembly sends a variable, Profile Ignition Pickup (PIP), voltage signal to the Ignition Control Module (ICM), which is mounted on the left fender wall, and to the PCM, which uses it to determine crankshaft position and engine speed. Using the signal and information provided by other engine control sensors, the PCM determines the appropriate ignition timing. The PCM then sends a Spark Output (SPOUT) timing signal back to the ICM.

The ICM turns the Ignition Coil primary circuit on and off, according to the SPOUT signal from the PCM. Each interruption of the Ignition Coil primary circuit causes the Ignition Coil secondary circuit to produce an open circuit high voltage pulse of up to 40,000 volts. These high voltage pulses are routed to the Distributor, which sends them to the spark plugs.

The PCM monitors the ICM'S control of the Ignition Coil through the Ignition Diagnostic Monitor (IDM) circuit.

If the ICM does not receive a SPOUT signal from the PCM, the ICM will set timing at a fixed value.


Keep in mind the earlier distributor mounted Ignition Control Modules works the same. By removing the PCM the ICM now controls the firing of the coil. This is a GREAT troubleshooting aid.

 

Did you check to see if your cam is spinning? Broken chain?

 

Thankx rla2005. I started reading FAQ, trying to learn my way around here. Yes, i have seen you post this before, and i want to say thankx, I have been to that page,and it is good. I just need to start a thread i guess to talk about what all i have did to this truck. I have owned it for 5yrs or so. It started doing the same thing i have read about on here time and again, It gets warm, pull in to get gas, it wont start, till ya let it cool down for five minutes. This went on for six months, i asked all the local mechanics about this, no one had an answer. I knew it would completly break down for good, which is where it has been for a month. I have changed every part in ignition system, PIP twice. only thing i have not done is EEC. Checked all components, except PIP bench, that is why i was wondering. I read somewhere that SUBFORD posted a test, but i cannot find it now, and i believe it was with a pip mounted in dizzy on bench, with a 9v battery. I dont want to keep posting in other peoples threads, so i am trying to learn to do my own. But, hey if it helps them, thats great, thats what i am wanting to do. thankx

 

If you can get yourself a Haynes manual, it has a real good walk through, and here is good...Part 5 -Ford Ignition Module Test. Fender Mounted Module (ICM)....computer may be bad

 

Great link slip ford man. Thanks a ton.

I take that back. Fantastic link. This bad boy's got it all.