Revisiting the HEI Mods (OBDI and OBDII)

[lilpavel]

I posted a similar question in the 2.5 Tech Section and got no answers at all. So I am going to give it a shot here also hoping that someone in here knows what to do or has accomplished this feat.

I am attempting to do the HEI Mod on my 97 DD PGT. I found a schematic that someone made from a 96 but it had a Blaster coil on it and I do not want to utilize the external coil. I just want the HEI, so I called Travis and we spoke several times about this and I sent him the picture that I found and he modified it to what he thought was correct.

Here is the original HEI w/ Blaster Coil
http://i1103.photobucket.com/albums/...nstall1996.jpg

Here is the Modified HEI w/ no External Coil
http://i1103.photobucket.com/albums/...ly_install.jpg

So after the above schematic/picture not working, I sat down and compared someones schematic of their HEI Mod on a 94 and I re-wrote it on paper and compared it to the 94 wiring book. I then took that schematic and labeled the wires. I then took the 97 electrical book and drew the same schematic and labeled the appropriate wires according to the 94 HEI schematic.

Here is the schematic I based my re-drawings from
http://i1103.photobucket.com/albums/...Misc/HEI-1.jpg

Here is the comparison of both
http://i1103.photobucket.com/albums/...omparision.jpg

Now after I have tried both combinations all I can only get the car to run off the stock disty with NO HEI. I was going to try it with the external coil, but the ZE Cap that I have does not fit my 97 disty. So I will have to modify the disty cap to attempt the HEI w/ External Coil.

Can anyone see anything that I did wrong or something else that I should try to get the car working on the HEI w/out External Coil?

[siknin]

do you have spark with either of those diagrams?

[lilpavel]

No I do not

[siknin]

"b" may need to be swapped to the other side.... that is to wire on the opposite side of the 3wire disty plug

also make sure the ground is solid and even ground the entire back of the hei if possible and dont rule out the hei being faulty.... sometimes they pop if wired wrong or not lubed before mounting.....


so it could be

a: bad hei

b: no power because of incorrect wiring

c: ground not good enough

[daweb]

i think the middle wire on the 3 wire needs to go to c not the the 3rd wire 1st wire the one on the left goes to b when looking into the plug

[lilpavel]

"b" may need to be swapped to the other side.... that is to wire on the opposite side of the 3wire disty plug

I'm not following you, can you draw something up and email it to me or post it here.

also make sure the ground is solid and even ground the entire back of the hei if possible and dont rule out the hei being faulty.... sometimes they pop if wired wrong or not lubed before mounting.....


so it could be

a: bad hei

b: no power because of incorrect wiring

c: ground not good enough

The HEI was grounded to the front VC off one of the 10mm bolts that holds the front breather tube on the VC. I also added the lube to the back of the HEI today. I also added an extra ground to the HEI, grounded it to the same ground that the negative terminal uses.

The HEI could be bad, I remember reading a way to test it with a 9v Battery and a Volt Meter.

My guess is that it is wired incorrectly or the HEI cannot be done on a 97 unless you use an external coil. That is the purpose of me posting here to see if anyone knows the correct schematic or has done this in the past.

i think the middle wire on the 3 wire needs to go to c not the the 3rd wire 1st wire the one on the left goes to b when looking into the plug

Not following either, are you sure you are looking at the correct schematic? I made two different ones for comparison and I only attempted to test the 97 version, not the 94 version.

Thank to the both of you for attempting to troubleshoot this with me!

[daweb]

on this thread go to post #4 cougar found an error in the diagram http://forums.probetalk.com/showthre...hlight=hei+mod

[siknin]

If you think the wiring is correct, I have used a 1995 gt disty on 1996gt and it works. So having said that the 95-97gt would use the same hei Diagram. As posted above by "Daweb". If I were you I would purchase a new Hei and double check that the "b" is wired to the correct spot on the 3pin disty.

again if your diagram matches the 95gt diagram(the disty is the same as the 96gt and 97gt) then you just have a faulty hei, I bought two at a time just to have a spare

[94pgt320hp]

http://www.clubprotege.com/wil/howto/hei/index.htm


this may help...

[lilpavel]

I spoke with Cougar last night via PM and we concluded that my diagram is correct here is some of our conversation

From the link you sent the 97 is the same as the 95 so you need to follow the instructions below which I believe is what your lower comparison diagram shows.

Pin #6 (Blue/Orange) is the trigger signal from the ECU and should be connected to the "G" terminal of the HEI module. Pin #5 (Black) which is the module's original switching transistor's ground can be disconnected and grounded with the HEI Module grounds "W" terminal.
On the 3 pin connector, Pin #1 is the left-most pin when looking straight into the plug with the connector latch facing up. This wire (Black/Pink) is the V(Bat+) 12V signal from the ignition switch. This wire should be spliced into and sent to the HEI "B" terminal. Pin #2 (Yellow/Green) is the middle wire and is the coil negative (-) wire which should be spliced into and sent to the "C" terminal of the HEI module. (For info only, this wire is also the tach wire in our "Data Link Connector") Pin #3 (Green) is also a coil negative wire but with a resistor in-line which feeds the vehicle tach. This wire is left alone.

Here is another confirmation that my schematic is correct

http://i1103.photobucket.com/albums/...sc/hei1997.jpg

basically yes you are right


You might then try leaving #5 connected.

Here is the information to test the HEI

If this helps...this is the test for the Flamethrower HEI 4 pin module. It may apply to other 4 pin HEI modules (I don't know).


Here is the test for the Flamethrower HEI 4 pin module:

Here is a test for the HEI module. You will need a 9V battery, clip leads and a voltmeter.



1) Connect the ‘B’ and ‘W’ terminals of the module to battery (+)

2) Connect the metal back of the module to the battery (-)

3) Connect the voltmeter black lead to the ‘C’ terminal

4) Connect the voltmeter red lead to the ‘B’ terminal

5) Set the voltmeter to DC volts. The voltmeter should read between 7.0V to 9.0V

6) Connect the ‘G’ terminal to the battery (-)

7) The voltmeter should read about 0.0V

[KLDE93]

I spoke with Cougar last night via PM and we concluded that my diagram is correct here is some of our conversation


Here is another confirmation that my schematic is correct



Here is the information to test the HEI

replied to wrong post

[KLDE93]

That test is for HEIs with ground path on the metal back...not the holes. I suppose you could ground the neg 9V batt to mounting holes...or could be both.

[KLDE93]

...bare in mind also that BePro and I came to the conclusion that wire codes don't always match up with the correct pin (three pin connector) on a 93. Be advise this could be an issue on the 97 as well....even on the ignitor connector harness.

[lilpavel]

I have both Ford wiring books for the 94 and 97. I went through the books and compared a schematic of the 94 which is known to work and I transferred that schematic to the appropriate wires on the 97 with the different pin outs. I was unable to get it to work, but I really think it was a bad HEI. I haven't tested it yet using the method you listed because I think the problem with my car is not in the disty. I have a couple more things to test on the car to determine the problem. I will attempt to resolve the HEI mod on the 97 when I have some more time.

The biggest thing is making a thread with useful information and links and pictures that actually work for everyone else. During my research I encountered a lot of dead links and missing pictures. Hopefully I will have all of this figured out soon.

KLDE93, thanks for your help though, maybe we can get it all figured out in the end and transfer the appropriate info to a thread available for everyone.

[ugasouthernprid]

Did you figure it out? I assume so...