EFI Distributor swap with remote TFI

brianstrange · Jan 4, 2012

I'm trying to retrofit a remote style TFI Distributor from a 96 Bronco (similar to 94-95 5.0 Mustang) onto a 93 EFI Harness. There's plenty of info re-using the early 5.0 Distributor, and adding the three wires etc.... however, I want to run it upstream, and use the newer 8 pin dizzy. Does anyone have a pinout of the newer TFI and Distributor? Veryuseful.com just shows the 6 wires going to the remote TFI, and excludes the harness between it and the distributor.

Thanks

70_Steve · Jan 4, 2012

brianstrange said:
I'm trying to retrofit a remote style TFI Distributor from a 96 Bronco (similar to 94-95 5.0 Mustang) onto a 93 EFI Harness. There's plenty of info re-using the early 5.0 Distributor, and adding the three wires etc.... however, I want to run it upstream, and use the newer 8 pin dizzy. Does anyone have a pinout of the newer TFI and Distributor? Veryuseful.com just shows the 6 wires going to the remote TFI, and excludes the harness between it and the distributor.

Thanks

One of these might help.
http://www.oldfuelinjection.com/files/remote_TFI_harness1.gif
http://www.oldfuelinjection.com/files/remote_TFI_harness2.gif

One for Grey and one for Black.

Viperwolf1 · Jan 4, 2012

This what you're looking for?

brianstrange · Jan 4, 2012

EXACTLY! Thanks guys!

Broncobowsher · Jan 4, 2012

Just a quick warning, the remote TFI distributor is a touch shorter then the non-remote version. About ½" which can cause clearance issues on some applications. I had issues clearing the fuel rails with an Explorer intake. It is possible to gut the TFI distributor and put the remote guts in it. Still need to plug the hole for the TFI going under the cap. You need to notch the housing to accept the harness grommet.

Also watch the TFI style, some are computer controlled dwell others are not. Gray vs. black housing in stock configuration. Gray is TFI controlled dwell, black is computer controlled.

brianstrange · Jan 4, 2012

Okay, so after a second of confusion, there are two seperate shieled runs. One from ECM to TFI, and the other from TFI to Distributor. As I remember, the shielding must only be grounded on one side of each run.

Thanks again!

Bronco_69 · Jan 4, 2012

i did the exact swap about three years ago. be sure both use the gray module and be sure to shield the wires. it ran great with no issues.

i used a modified 5.0 mustang harness, 351w with a 96 bronco distributor, and a remote tfi from some v6 car.

Steve83 · Jan 4, 2012

This shows all the stock configurations from '92-96, and the caption explains the differences:

Extra ground points on the shields won't hurt anything.

I did this swap on Frank's '75 last year. There was no perceptible change in driveability.

brianstrange · Jan 18, 2012

Ran into more questions.

1)Based on the Gray module diagram, pin 3 of the distributor is shielded between the distributor and the TFI. The truck I pulled it from had it routed outside of the shielding.

2) I have read that there should only be one ground for the whole shielded run from the EEC to the distributor, however, I'm getting continuity between the distributor housing, pin 2 and pin 3 of the distributor plug. It brings me to this question..... Is the ground cable that runs thru the shielding on the 94 & 95 Mustangs grounded at the ECU?

3) Does the remote TFI heat sink need to be grounded? I'm mounting it to a fiberglass Tub.

Also, Broncobowsher, I'm guessing that the Mustang remote style TFI distributors are shorter for clearance issues they had under the hood. I was scratching my head as to why the full size Bronco, and 94 /95 Mustang distributors had different assembly part numbers. They housed the same electronics, but The Bronco one is taller.

Broncobowsher · Jan 18, 2012

I only delt with mustang distributors. Don't know if the truck versions are taller or not. If you are doing a truck distributor with a mustang computer check the hall effect wheel. The Mustang takes a signature PIP so the computer knows where cylinder #1 is at. That is one of the windows has a slightly different shape. Trucks typically being batch fire may not have the special window. I have been told that you can change out the PIP wheels to fix that.

mattt · Jan 18, 2012

I think by 96 the trucks went sequential and mass air....but yes, have a look at the wheel for one of 8 windows that is slightly smaller.

brianstrange · Jan 18, 2012

Broncobowsher said:
I only delt with mustang distributors. Don't know if the truck versions are taller or not. If you are doing a truck distributor with a mustang computer check the hall effect wheel. The Mustang takes a signature PIP so the computer knows where cylinder #1 is at. That is one of the windows has a slightly different shape. Trucks typically being batch fire may not have the special window. I have been told that you can change out the PIP wheels to fix that.

The PIP for the 96 Bronco, and 94/5 Mustang are the same part number, so I'll assume I'm good there.

Viperwolf1 · Jan 18, 2012

brianstrange said:
Ran into more questions.

1)Based on the Gray module diagram, pin 3 of the distributor is shielded between the distributor and the TFI. The truck I pulled it from had it routed outside of the shielding.

2) I have read that there should only be one ground for the whole shielded run from the EEC to the distributor, however, I'm getting continuity between the distributor housing, pin 2 and pin 3 of the distributor plug. It brings me to this question..... Is the ground cable that runs thru the shielding on the 94 & 95 Mustangs grounded at the ECU?

3) Does the remote TFI heat sink need to be grounded? I'm mounting it to a fiberglass Tub.

1) Pin 3 is ground for the remote TFI module. It doesn't need to be inside the shielding.

2) I doubt it's run all the way to the ECU. Probably just run to the harness common ground point at the back of the intake. According to the RJM diagram pin 2, 3 and 6 should all be continuous and grounded at the distributor connector.

3) I doubt the heatsink needs to be grounded. It doesn't if there are no terminals touching it. It needs to be somewhere in the airflow though.

brianstrange · Jan 19, 2012

Viperwolf1 said:
2) I doubt it's run all the way to the ECU. Probably just run to the harness common ground point at the back of the intake. According to the RJM diagram pin 2, 3 and 6 should all be continuous and grounded at the distributor connector.

Viperwolf, the Mustang harness that I'm building this off of has the shielded run from the distributer to the ECU, grounded with Pin 20 on the kick panel, ending in an open manner (not grounded) near the distributor. If I use the newer distributor, the hybrid of the two will offer a ground at each side. That could cause issues if the main motor to chassis ground failed. Seeing as the newer distributor offers ground on that side, I'm considering removing the bare wire ground connection from the kick panel ground point, leaving pin 20 grounded by itself, and the shield getting ground from the distributor side.

I'd like to get any thoughts on doing this....

(Updated)

Viperwolf1 · Jan 19, 2012

After looking at some more diagrams it looks like pin 20 is ECU case ground and the PIP, SPOUT and IGN gnd are shielded all the way back to the ECU. The case gnd is connected to the shielding which makes sense. The case isn't grounding the shielding. The case is part of the shielding. You should ground the shielding at one end or somewhere in between. Having 2 different ground points is not a good idea on these small signal wires. Lots of people think that more grounds are better but it's not always true. Having one good common ground point is better.

brianstrange · Jan 19, 2012

Viperwolf1 said:
After looking at some more diagrams it looks like pin 20 is ECU case ground and the PIP, SPOUT and IGN gnd are shielded all the way back to the ECU. The case gnd is connected to the shielding which makes sense. The case isn't grounding the shielding. The case is part of the shielding. You should ground the shielding at one end or somewhere in between. Having 2 different ground points is not a good idea on these small signal wires. Lots of people think that more grounds are better but it's not always true. Having one good common ground point is better.

That's what I was thinking, thanks for the reinforcement. I'll be using the distributor as the ground point on mine, and will cut and terminate with the shielding at the ECU. Maybe the newer design provided progress of some sort.

Pin 20 only shares the grounded connector with the bare ground wire on the EEC A9L harness.

brianstrange · Jan 20, 2012

I just created this wire diagram showing how I wired up my tfi, based on the location of the components. This is for a remote style GRAY TFI

Steve83 · Jan 21, 2012

brianstrange said:
1)Based on the Gray module diagram, pin 3 of the distributor is shielded between the distributor and the TFI.

What diagram are you looking at? 3 is the ground, which isn't shielded.

brianstrange said:
2) I have read that there should only be one ground for the whole shielded run...

I don't think so - it can be grounded 100x. And the nature of "grounded" is that anything that's grounded is grounded to everything else that's grounded. So if you test between any pair, you'll find continuity.

brianstrange said:
3) Does the remote TFI heat sink need to be grounded?

No. The heat sink isn't electrically connected to anything. The TFI grounds through it's connector, as the diagram I posted above shows.

brianstrange said:
I'm guessing that the Mustang remote style TFI distributors are shorter for clearance issues they had under the hood. ... but The Bronco one is taller.

More likely to clear the taller/thicker truck intake. Even a truck dist. is shorter than a car upper intake.

brianstrange said:
That could cause issues if the main motor to chassis ground failed.

At worst, it would vaporize a small section of the shield wrap, which is probable equivalent to a 0.1A fuse.

This might interest you:

Viperwolf1 · Jan 21, 2012

Steve83 said:
I don't think so - it can be grounded 100x. And the nature of "grounded" is that anything that's grounded is grounded to everything else that's grounded. So if you test between any pair, you'll find continuity.

You need to read up on ground loops.

Explorer · Jan 22, 2012

Viperwolf is correct as usual. A single point of ground is always better. Especially dealing with electronics. A term never mentioned is bonding. This is creating a ground path that is equal in potentional throughout the electrical system.

EFI Distributor swap with remote TFI

Bronco Guru

Old Guy

electron whisperer

Attachments

Bronco Guru

Total hack

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Total hack

Bronco Guru

Bronco Guru

electron whisperer

Bronco Guru

electron whisperer

Bronco Guru

Bronco Guru

Attachments

Bronco Guru

electron whisperer

Bronco Guru

Similar threads