AdrianE

I have an LT8 running on my 3rd gen (1995), I bought this 2 years ago and haven't had any problems with it apart from some tuning glitches. I did have a Haltech E11v2 on this car, but it had some ignition timing problems and I think it needs to go back to Haltech to get fixed.

Anyway, I re-installed the LT8 using the wiring diagram in the manual (the same diagram as on the Microtech's website ie. "LT813BTS6fuelign.pdf"). I wired the connectors directly to the appropriate wires in the engine wiring loom, as per this diagram. Before this I used to run the LT8 with the "plug and play" adpater I bought it with, and it worked just fine. (I will eventually re-install the Haltech via its own loom when it's repaired, and I got fed up of wiring and un-wiring it to the standard 3rd gen Loom connectors).

I think some of the wiring in the LT8 wiring diagram is wrong eg. the Home and Speed connections are swapped around! I got an RPM error when I wired them this way. In any case, the main problem that I have is an RPM signal of zero rpm displayed while I'm cranking the engine over at approx. 200rpm. The engine will not start, and not even catch! But I have tested for sparks on each HT lead (via a timing gun), and they are firing. I have checked for fuel; I can smell it in the engine bay and coming out of the exhaust, so I think the injectors are working. The LT8 map I'm using is the same one I have used before and it worked just fine.

Does anybody who has installed an LT8 (on a 3rd gen RX7) via the 'flying loom' have a definitive wiring diagram? I can check and re-check my connections to the LT8 as many times as I like, but if the wiring diagram is wrong then the car will not run!

I have an oscilloscope (via my laptop) and have measured the pulses coming from the Home and Speed (Trigger) sensors. The pulses appear to be correct for a cranking speed of 200rpm. So I cannot figure why I get ZERO rpm on the Microtech laptop software. Any ideas?

Adrian
(UK)