Fitting a HEI Module in Transistor Ignition Unit 1977 280Z

[EuroDat]

That is a strange problem you are having. I have had nothing like it, except the reverse red and green wires stopping it revving past 2500 - 3000rpm.

If I had to guess I would think it would be something with the HEI, but never heard of one going like that.

What brand HEI is it? 

[kyle146]

2 minutes ago, EuroDat said:

That is a strange problem you are having. I have had nothing like it, except the reverse red and green wires stopping it revving past 2500 - 3000rpm.

If I had to guess I would think it would be something with the HEI, but never heard of one going like that.

What brand HEI is it? 

Just a cheap Duralast version I had picked up from Autozone for some testing. Plus it had a warranty compared to Amazon. Going to try to return it today and see if thats the problem.

[EuroDat]

When I first started testing I used a elcheapo HEI from Alliexpress for 10 euro. It worked, but gave up after a week testing. It could be the HEI.

[kyle146]

1 hour ago, EuroDat said:

When I first started testing I used a elcheapo HEI from Alliexpress for 10 euro. It worked, but gave up after a week testing. It could be the HEI.

Well I just bought a new HEI and it definetley was the issue. car starts now but it seems my timing is way far forward to the point that when I adjust it, it sits at 15 degrees and wont go any lower at its full adjustment. Looks like I have a little more work cut out for me

Edited August 29, 2019 by kyle146

[EuroDat]

Good to hear you found the problem.

Your timing issue is probably a incorrsct positioned distributor mounting plate. The distributor has two adjustments. The one you use on the front side of the distributor and the other is at the back. The back one is hard to get to and under the distributor. It's an M5 with a 8mm hex head.

See photo. Please note the plate in the photo is for a 280ZX and looks a little different to the 280Z version

[EuroDat]

Better to remove the distributor to adjust the rear screw and then do the timing again.

[kyle146]

1 minute ago, EuroDat said:

Good to hear you found the problem.

Your timing issue is probably a incorrsct positioned distributor mounting plate. The distributor has two adjustments. The one you use on the front side of the distributor and the other is at the back. The back one is hard to get to and under the distributor. It's an M5 with a 8mm hex head.

See photo. Please note the plate in the photo is for a 280ZX and looks a little different to the 280Z version

Ok so the bottom one is more of a rough adjustment and the top is the fine adjustment? 

 

[EuroDat]

Yes. Make a note on witch direction you need to turn the distributor, remove it and correct it with the course adjustment.

Have you checked the vacuum and mechanical advances are returning to their start postitions?

[kyle146]

37 minutes ago, EuroDat said:

Better to remove the distributor to adjust the rear screw and then do the timing again.

Ok so just out of curiosity, i unplugged the HEI and put the old module back in. The car fires right up and the timing is exactly where it needs to be. 

[kyle146]

21 minutes ago, kyle146 said:

Ok so just out of curiosity, i unplugged the HEI and put the old module back in. The car fires right up and the timing is exactly where it needs to be. 

And as soon as i put the hei back on, timing is off and it runs like crap. Again out of curiosity I reversed the red and green to see if it would rn and it starts up with no problem. Going to try to see if it will rev past the 3000 mark

[EuroDat]

Strange to see such variance in the two HEI units. Are they the same brand / manufacturer?

[EuroDat]

32 minutes ago, kyle146 said:

i unplugged the HEI and put the old module back in. The car fires right up and the timing is exactly where it needs to be. 

Do you mean the old original TIU? That can happen. The HEI can activate at a different point in the reluctor wave form which will effect the advance.

My timing was different when I went from TIU to HEI, but not as much as what you are experiencing.

Edited August 29, 2019 by EuroDat