Do I need to replace my CDI box?

[Walter_Middie]

Tom

The tach: I'm not exactly sure how to hook this up. Do I have to go digging through the wiring bundles to find the black and purple wire? Does it run through the 14 pin connector?

The tach wire does not go through the 14 pin connector. Follow one of the white wires from the CD unit (there are only 3 wires going to the CD unit - 1 red and 2 white) to a white plactic connector near the CD unit. The black/purple tach wire should come off of this connector and run forward from there straight to the tach.

I have Beru wires on my car with MSD - no issues.

I have a complete write up on MSD installation for a M.Y. - but it's not near me right now. I can send it to you later today if you having issues.

[Tom '74 911]

Originally posted by Walter_Middie
Tom

The tach wire does not go through the 14 pin connector. Follow one of the white wires from the CD unit (there are only 3 wires going to the CD unit - 1 red and 2 white) to a white plactic connector near the CD unit. The black/purple tach wire should come off of this connector and run forward from there straight to the tach.

I have Beru wires on my car with MSD - no issues.

I have a complete write up on MSD installation for a M.Y. - but it's not near me right now. I can send it to you later today if you having issues.

Thanks for the info on the tach wire and also the Beru wires. I've got a few write-ups on installing an MSD system and some photos etc... all from the archives here. The wiring appears straightforward - the MSD directions are pretty good too. Mounting the beast of a box may be my greatest challange. I've got an external voltage regulator and rear window relay to deal with. That's my goal this afternoon - to get the mounting figured out.

Thanks,
Tom

[Tom '74 911]

Up and running! I installed everything last night and I seem to be good to go. The wiring was not too bad, I found the tach wire and it works. After re-adjusting my valve adjustment from over the winter, a new rotor and cap, new plug wires and the new MSD CDI box, its seems to be running really smoothly. (hopefully I didn't just jinx myself for my 5 hr. drive tomorrow). I've got some tidying up to do w/the wiring and elect panel in the engine compartement, but as it is now, it works and will get me through - even if it's not the prettiest. Also, I checked the battery voltage while running and it seems good at 14.5V. Hopefully that's the last electrical issue that I'll have to deal with for a while.

I'd love to know what caused my issues - whether it was something I inadvertently did or if something just wore out and quit. I plan to do some more investigating next week when I have more time.

Thannks for all the help,
Tom