removing tach in 71, car won't start even with haltech?

[philUK]

Hi all,

I'm in the middle of replacing my 240z tach with a 280z one, I tried starting my car without the tacho plugged in at all, and the car wouldn't idle, although it would turn over..

I'm running a haltech ecu, so I thought the problem with needing the 'loop' through the 240z tach wouldn't be an issue?

Otherwise its just a coincidence that something else has happened, or I did something whilst removing the tach.. Why didn't I try to start the car BEFORE removing the tach to check everything was ok:stupid:

please help its drivin me mad!

[LanceM]

Yes you need the tach in to run acording to the drawing I have. If you want to run without the tach short the two tach wires together otherwise there is no 12V to the coil. I just put a ZX dizzy in my 240 and all I had to do to make the 240 tach work was short across the ballest resistor.

[philUK]

Thank for the reply, but with my engine swap and e6k I don't have a single coil, or dizzy! since all this is bypassed I though I wouldn't need the tach..!

[LanceM]

Acording to my drawing the green/white wire comes from the ignition switch to the tach, black/white goes from the tach to the coil. If you are still using the black/white for power to your ignition you won't be getting it without either a tach in place or with the green/white and black/white wires attached to each other where the tach would be normally hooked up.

[philUK]

thanks for the help!

Hopefully I'll be able to see how it is all hooked up this weekend!

[philUK]

Phew - think I got to the bottom of it. seems was not realted to the tach after all. I think it was the power relays for the haltech. I hadn't started the car for a month or so, and apparently if the relays get damp, you just get no power to the haltech. which obv. just cuts the engine.. I got the car starting, but now only starts at the 2nd or 3rd attempt, where it used to start first time everytime, so something still isn't quite right.. at least its running again though!