PINTO CAR CLUB of AMERICA

Shiny is Good! => General Pinto Talk => Topic started by: Wittsend on May 25, 2018, 08:11:01 PM

Title: Ford TFI to GM HEI ignition module conversion
Post by: Wittsend on May 25, 2018, 08:11:01 PM
While looking up ignition information for another matter I came across this diagram to convert the Ford TFI module (Used in most 2.3 EFI conversions) to the GM HEI module. At least I assume that is the application. Not sure of the significance (cost, reliability???) but thought I'd post it here for information and feedback (do I have this correct? Maybe not I'm not seeing where the ECU comes into play) from others. So, yes, opinions PLEASE.
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: dick1172762 on May 26, 2018, 10:11:34 AM
VERY good set up for any engine! In v-8 use its good for 6000 rpm but its good for 12000 rpm on a 4 cylinder plus its very easy to carry a spair in the glove box. Their cheap too.
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: pinto_one on May 30, 2018, 01:05:47 PM
also if you do use the GM module make sure you bolt it to a good heat sink , heat kills these , and for useing one to replace a ford TFI module I think they have one that has a extra leg for timing to be adjusted to change the timeing by the ECM , have to look into it to see for sure ,
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: Wittsend on May 30, 2018, 02:11:06 PM
Yes..., after I posted initially I realized that it seemed not necessarily for the computer timed systems but as you indicate - maybe. So, let us know if you find out more.

 The later TFI cars had an external heat sink (not distributor mounted) and that is what I'm using positioned by the master cylinder on the inner fender. One just needs to be careful because there were at least two TFI's (that I know of) and they don't cross fit size wise to the heatsinks as well as the wiring method. If one is staying with the stock '88 and under parts you want the older heat sink. I got me heatsink out of a 90's LTD. And you will have to fabricate wires from the distributor to the TFI. I believe the wires should be shielded too.
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: pinto_one on May 30, 2018, 04:18:32 PM
I did some looking on a GM module that might work for the computor controled timeing , yes they do make one but have to later checkout the wireing details to see if it may work or not , but on the other hand they do still make a Accel HP unit for the ford TFI ign , the wiring I got off a F-250 ford truck with the 460, with the heat sink , planning on installing it on my 2.8 CFI fuel injection conversion , its a pain to get too because the dist is in the back and the TFI module is faceing the firewall , it may never go out because I install a new one but the idea if it does it will be a hot day and out in the middle of nowhere on the side of the road , so having it bolted to a easy place to get too is good , also keep a extra computor with the car also , anyone planning on doing this had better make time to go to the wrecking yards and pick it while you can , most of this stuff is over twenty years old and slowly going away, 
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: Wittsend on May 31, 2018, 01:00:58 AM
... anyone planning on doing this had better make time to go to the wrecking yards and pick it while you can , most of this stuff is over twenty years old and slowly going away, 

Couldn't agree more. 10 years ago the Turbo Coupes were nearly half a dozen every time I went to Pick A Part. Today... can't recall one being there for at least 3 years now. The newest T/C (an '88) is now 30 years old!!! Often we talk about these parts like they are everywhere. But as you have stated they are disappearing FAST!
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: 65ShelbyClone on May 31, 2018, 11:43:15 AM
The four-pin HEI modules are cheap and plentiful, but don't have provisions for computer-controlled timing. Using one in place of a TFI will result in fixed timing. They work well with a Duraspark distributor though.

There are several other HEIs with seven and eight pins that were designed for computer control and they are 5v logic compatible. I don't recall if they trigger on rising or falling signal nor which method the EEC-IV uses. If they're the same, then it's conceivable the GM module could be retrofitted in place of a TFI. If not, then it might require addition of a logic inverter.
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: pinto_one on May 31, 2018, 02:24:12 PM
I was looking over the seven pin GM module and found the same info , 5 volts and a ref signal wire , so I am not going even try doing so because OEM is stiil good and aftermarket is still out there for now , just going to buy two new ones and put one in the car just in case (test it first ) the other in my goodie box, the four pin GM module will be around because I have noticed quit a few high performance distribtor makers are useing the top of the GM distribtor on fords , dodge and others , so supply will still be out there , as for the old ford Box the days my be numbered ,
Title: Re: Ford TFI to GM HEI ignition module conversion
Post by: 65ShelbyClone on June 01, 2018, 11:06:44 AM
Aftermarket modules are also notoriously inferior to genuine Motorcraft TFIs.

Fortunately for me, the standalone ECU does all the heavy lifting now and the TFI module just provides an RPM signal. I could have the TFI function as original, but not with spark cut rev limiting because the TFI has a failsafe where it continues to provide spark at base timing even without an ECU signal. I would expect that GM modules to do the same. This also prevents the use of extreme ignition retard which can be useful for getting a turbo to light-off.  8)