Poor Man's GT40 Diagnosis

Hot loping (rolling idle) problem fixed with Idle Speed Control Valve:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=24848&title=gt40-engine-loping

Part found on Rock Auto:
IACV PN: e9se9f715eb (off the original valve)
http://www.rockauto.com/catalog/moreinfo.php?pk=945342
$55.79 + shipping

Updated Spreadsheet

Engine Missing Solved by ECM Relay:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=23424&title=engine-missing

Another fuel pump popping a breaker:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=26855&title=circuit-breaker-popping

You're welcome. Hope it helped.

I updated the IACV line with the Autozone PN, the Napa one is there too.

Clogged Fuel Pickup tube causing reduced top speed, surging and poor performance:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=27274&title=gt40-issues

Old Post with a cracked tube in the FCC leading to very poor performance, backfiring etc:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=21983&title=pcm-gt40-backfires

Another tiny crack in the fuel line inside the FCC. This one caused very sudden, total loss of performance. Inability to idle and rev up:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=27375&PID=351303#351303

Updated Spreadsheet

Bad gas causes hesitation, stalling and limited top speed:
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=27432&title=gt40-fuel-pressure-stalling

Updated Spreadsheet

1997 GT40 with approx 700 hrs.

Symptoms: An otherwise perfectly running engine suddenly dies and won't restart. Turns over but won't catch. An hour or more later, starts and runs fine. Later dies and won't start again.

Solution: Bad Ignition Module or TFI(Thick Film Ignition).

Replace TFI by removing it from the heatsink. These TFIs come in four flavors - distributor mount and remote mount, in grey and black. Make sure you get the remote mount, grey one - referred to as "Remote Mount Gray TFI-IV 'Push Start' ICM".

Part Numbers:
Motorcraft - DY1075 (supercedes DY533)
Ford - 5U2Z12A297B (supercedes E8DZ-12A297-A)
Wells - F125
Niehoff - FF411
BWD - CBE33
Standard - LX226
Napa (Echlin) - TP33 (~$73)
Delphi - DS10053
Transpo - FM533

Image of TFI mounted to heatsink


Image of replacement TFI


Edit:
You'll need a deep socket 7/32 to remove/install the TFI from the heatsink.

The replacement TFI also will come with with a silicone that is applied to the metal back of the TFI, where it comes in contact with the heatsink.

The TFI is the grey plug facing the front of the boat, located under the black cowling, next to the coil near the throttle body.

See Lewy's photo:

Keith wrote: Solution: Bad Ignition Module or TFI(Thick Film Ignition). Replace TFI by removing it from the heatsink. These TFIs come in four flavors - distributor mount and remote mount, in grey and black. Make sure you get the remote mount, grey one - referred to as "Remote Mount Gray TFI-IV 'Push Start' ICM".

Keith was the module you replaced grey or black?

I was working on my boat today getting it ready for the summer and while inspecting my TFI module (was going to re-apply heatsink compound) found that it was a black module. This had me initially thinking somewhere along the line it must have been replaced with a incorrect module. The main difference between the black and grey modules is that the grey module sets the dwell while with the black module the computer controls the dwell.

The GT40 manual in the reference section (3F-13 page 222) species the use of a black CCD (computer controlled dwell) TFI module. This led to some research and I found what I think is the correct answer. I will confirm this in the next few days at my Ford parts dealership but it already looks conclusive from this article.
TFI Modules Grey or Black

from this article:-

"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 driveability 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."

These should be the correct part numbers for the GT40 TFI
Remote Mount Black CCD "Computer Controlled Dwell" ICM

Motorcraft - DY1077 (supercedes DY679, DY667, DY645)
Ford - 5U2Z-12A297-D (supercedes F1PZ-12A297-A)
Wells - F139
Niehoff - FF413
BWD - CBE40
Standard - LX-241
NapaEchlin - TP29
Delphi - DS10056
Transpo - FM544

Keith maybe your TFI had been swapped out earlier with incorrect "grey" module. It would be easily done as stated in the article as they look identical apart from colour and will still function just not as efficiently.

Keith it would be nice to get a answer back from PCM. But do not hold your breath still waiting for their answer on the modification to EEC fuse wiring on the GT40 engines.

The manual in the reference section is for the early GT40 without the FCC.
It does specify the use of a black CCD TFI unit. (3F-13 page 222)

Also the article from Ford Engineer David Sill has a method of determining which type of TFI is required.-

"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."

The tan/yellow wire from pin 4 of the computer does go to pin 4 on the TFI connector on the GT40 engine.

So what started out as simple check ended up being a full on investigation. I was unable to source the correct TFI unit at any of my OEM auto part suppliers or local Ford dealer parts department. The only TFI module that ever made it to the Australian 5 litre V8 Windsor engine was the distributor mount "push start" grey module.

I decided to order one from the US just in case mine played up in the middle of summer at a very inconvenient time. Found it unusual that Skidim did not stock them. If they are a high failure part I would have thought they would carry them. Maybe they don't actually fail that much in the marine application.

Sourced it through Amazon who have good shipping rates to Australia.Black CCD TFI

Found this one which should be compatible but played safe with the genuine Motorcraft part. It maybe worth ordering one as a spare for US based owners at $29 though. Cheap Spare TFI

No problem. Just put in the final word on what is the correct TFI is to use, or if depends on the year?

Keith glad to see you finally received a reply from PCM. I have never managed to get a reply from them. You must have a inside man.

The number for the TFI module they gave you is the old number that was available when PCM were building the Ford GT40. It has been superceded by Ford since then.

Ford - 5U2Z-12A297-D (supercedes F1PZ-12A297-A)

The F15F 12A297 C1A was previously superceded by F1PZ-12A297-A

If you try an order a F15F 12A297 C1A the Ford parts man will tell you they no longer exist replaced by the new number.

These are the correct part numbers for the GT40 TFI
Remote Mount Black CCD "Computer Controlled Dwell" ICM

Motorcraft - DY1077 (supercedes DY679, DY667, DY645)
Ford - 5U2Z-12A297-D (supercedes F1PZ-12A297-A)
Wells - F139
Niehoff - FF413
BWD - CBE40
Standard - LX-241
NapaEchlin - TP29
Delphi - DS10056
Transpo - FM544

^^Or course, it looks like they are including the heat sink... which is probably a pricey chunk of metal.

Do a Google search on the part numbers Lewy provided. You find some decent prices - especially for the Wells F139.

- Keith