ignition module help!!!!!!

TFI modules do not vary for auto and stick - who told you that? The wiring back before the distributor differs but the modules do not.

jd-underdog said:

my local ford dealer told me that there are 2 different ones, depending on auto or manual? anybody know whats up

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dealer is full of crap

This is not the first time I've heard of this, but I don't know what the differences are. I don't remember ever having been asked when I've bought them, but I've seen some listed different. I think it may have to do with timing and being able to push start the car.

OK guys here is the straight skinny........If uyour TFI is gray - buy a gray one..........NOTHIN TO DO WITH AUTO OR MANUAL........

Most technicians who deal with Ford drivability and no-start problems have become very familiar with the Thick Film Ignition (TFI) system. Ford started using the six-pin TFI module with the EEC-IV computer system in 1983, and for years it remained basically unchanged.

The early TFI system, which Ford calls the "Push Start" TFI system, uses a gray TFI module. Originally, the module was mounted on the distributor. In the late '80s, Ford began to relocate it away from the distributor on some vehicles to provide better protection from the effects of engine heat, but system operation remained the same. It uses a Hall effect pickup (stator) in the distributor, which generates a battery voltage, 50% duty cycle square wave, called the PIP signal, to the EEC-IV PCM and the TFI module. The PCM processes this signal and sends out another battery voltage, 50% duty cycle square wave, called the SPOUT signal, to the TFI module. As long as the TFI module is receiving a SPOUT signal, it will fire the coil at the rising edge of that signal (except during engine cranking, when SPOUT is ignored) and the vehicle will run with the amount of timing advance commanded by the computer. If the TFI module does not receive the SPOUT signal, it will fire the coil at the rising edge of the PIP signal, and the vehicle will run at base timing. This is true on all TFI systems.

Ignition dwell with the Push Start (gray module) system is controlled by the TFI module alone, and increases with engine rpm. The Ignition Diagnostic Monitor (IDM) signal on a Push Start TFI system comes from the coil negative circuit and is filtered through a 22k ohm resistor to pin #4 on the EEC-IV computer. The computer monitors this circuit to verify a coil firing for each PIP signal, and sets codes if it sees missing or erratic signals. Another feature that is unique to the Push Start TFI system is the start input on pin #4 of the module connector. This is wired into the starter relay trigger circuit, and signals the TFI module that the engine is cranking. When the module sees battery voltage on this circuit, the SPOUT signal is ignored.

In the early '90s, Ford began using a different TFI system on certain vehicles -- the Computer Controlled Dwell (CCD) TFI system. The TFI module on CCD TFI is always black in color. There are a few major differences between the two systems. As the name implies, with the CCD system, the computer controls primary dwell. The CCD TFI module still ungrounds (fires) the coil at the rising edge of the SPOUT signal, but now the falling edge of the SPOUT signal (which had no meaning to the Push Start TFI module) is used by the CCD TFI module to ground the coil. The PIP signal remains the same 50% duty cycle square wave, but SPOUT signal duty cycle varies according to how much dwell is desired by the computer.

Another major difference between the two systems is the IDM circuit. Pin #4 on the CCD TFI module, which was the start circuit input on the Push Start TFI module, is now the IDM signal, sent directly from the TFI module to pin #4 on the EEC-IV computer. This signal is still a filtered (low voltage) version of the ignition primary waveform, but is filtered internally in the TFI module rather than through an external resistor. There isn't any start circuit input to the CCD TFI module; the module infers engine cranking from a low rpm input from the PIP signal.
Since these two TFI systems are so significantly different, yet so similar in appearance, parts application problems will inevitably occur. A gray Push Start TFI module will plug right into a CCD system, and vice versa. To make matters worse, parts books are often incorrect on TFI module applications! With the incorrect TFI module installed, the vehicle will run, but drivability and MIL (malfunction indicator lamp) problems will result. For instance, if a gray Push Start TFI module is installed in a CCD system, the computer will not be able to control ignition dwell, and the MIL will illuminate with memory codes for the IDM circuit set, as the gray TFI module is incapable of generating an IDM signal to the computer. If a black CCD TFI module is installed in a Push Start system, dwell will remain fixed, since the SPOUT signal duty cycle never changes. If in doubt about which TFI module belongs on a particular vehicle, consult the ignition system-wiring diagram for the vehicle. If the wire going to pin #4 on the EEC-IV computer comes directly from pin #4 of the TFI module, it is a CCD system. If not, it is a Push Start system.

Wow! Everyday I learn something new here!

Good info!

I guess even Ford engineers themselves realized their vehicles have to be Push Started periodically !!!

Icm

I have a similar problem with a 1994 5.8L F250. No spark from coil. I've tested and replaced coil, stator/pickup, ICM, and even the EEC-IV. Istill have no spark coming out of coil. I do have 12v at + side of coil primary wiring during "start" at ign switch. Any thoughts appreciated.

Tom, that was quite some post! You should write books - that was very articulate, understandable and polished!

(dave.luxem) yesterday i replaced my tfi/ignition module and pip sensor. if you need tips i made detailed steps on pics of rebuilding your distributor. shows how to get the gear off without a arbor press and how to get pins out w/o taps. pm if your interested.

You guys should pick up "How to tune and modify Ford Fuel Injection" It's probably the most comprehensive book Ive ever seen of the EEC IV and fuel injection in general. I just got it a week ago, so I havnt had time to really read all of it. But just skimming the chapters it has what every sensor, module, relay, etc. does and how to troubleshoot it; onboard diagnostics; what every code means and how to troubleshoot it. Troubleshooting by symptoms, as well as all the codes for the OBD2 system. Its only $20 and I think everyone with a fox body should own a copy

I've got the books and that was still an outstanding explanation!!!!!!!

Thanks.

93 teal terror said:

You guys should pick up "How to tune and modify Ford Fuel Injection" It's probably the most comprehensive book Ive ever seen of the EEC IV and fuel injection in general. I just got it a week ago, so I havnt had time to really read all of it. But just skimming the chapters it has what every sensor, module, relay, etc. does and how to troubleshoot it; onboard diagnostics; what every code means and how to troubleshoot it. Troubleshooting by symptoms, as well as all the codes for the OBD2 system. Its only $20 and I think everyone with a fox body should own a copy

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Most of us have that great book. However, I have not come across the info like Tom presented, nor in one summation. I find that I have to hunt and peck a little through the book if I want to read up on one particular system.

Thanks guys, take a look at when that was posted

~15 months ago

Lol, I didn't notice that. I wonder how it survived the multiple crashes.
I wasn't trying to take away from toms post, but merely trying to suppliment anyones thirst for more info on things of this nature