doesn't run great just on leading. is this normal ? or do I have something way out of sync ?

 

Have you tried swapping ignitors? I had an ignitor fail and was running pretty poorly, swapping it proved it was bad.

 

Are you still running the direct fire setup that you had recently installed? I recall the discussion about your particular distributor and whether or not it was the right one for that setup, did you confirm it?

And did you make sure to use heat paste and a good heatsink for the HEI ignitors? Once you introduce the direct fire, you do have two ignitors running the leading, so it is possible for one of those to go bad and then you just run rough on leading. And it could be one of the two leading coils in that scenario also.

I'd start by checking all of the wiring, especially the signaling from the distributor to the HEI.

 

good memory you got there ! ! yes, the leadings are direct fire. It should be the leading that it runs great on, because trailing are for emissions ?

 

Yes, LEADING is for performance, TRAILING is for fuel economy and emissions. Timing set properly ensures that Trailing has time to do its job. The car will run on Trailing alone, or Leading alone, if the timing is set properly. On Trailing only, it will lack power and you can hear and smell incomplete combustion at the tailpipe.

 

then it should run great on either trailing alone or leading alone ?

and I felt the Direct Fire coil and ignitor after a trip. they seemed to be as hot as the alternator and oil filter. So the heat sink is good.

 

It should run great on just leading. I've never tried to run just on trailing and drive anywhere. Back in the 90s, different RX7 same model, I had a bad leading igniter and it bogged badly while driving, i.e. lacking power as LongDuck says.

So I think the real problem is the performance of your leading-only direct fire (still using stock trailing yes?) is not up to expectations? So I think some basic troubleshooting, using a basic timing light you should be able to check spark on the front and the rear leading plug wires.

Or... swap back to stock leading and see if it runs well. At least then you know if the DF setup is the culprit. As in the TLIDFS thread, some distributors are better than others for the setup and your dizzy might not be the optimal year for this application.

Also, post a photo of your DF setup...the signal wiring should be clean, ideally shielded to ground, definitely twisted pair, and away from the high voltage wires.