I have a MSD and a re-production tach in my 69. I hooked the tach up 2 years ago by connecting it to the side of the MSD box for the tach and everything seemed fine.

Recently I’ve noticed a few hic-cups! One day while driving the car she backfired and shut off, it was hard to re-start and when it did, the tach was not working, before I got her home it cut off again, was able to start it and the tach worked fine.

The other day I started the car with no problem but every time I tried to go in reverse the car would shut off, if I started it in neutral, and put her in drive I was ok, but anytime I go into reverse she would cut off.

It may have been here or someone told me to unhook the tach so I did this and now I have no problems, also other gauges such as temp are working correctly again.

Is my problem with a bad tach or MSD box? Is there some other problem to look for like maybe a bad ground? How can I test the MSD box and/or tach?

THANKS

When is the last time you checked your cap and rotor btw? I know with my MSD cap/rotor because of the high spark and it was sitting in a body shop some condensation built up inside and really mucked up everything. I'd pull the cap and rotor and check to make sure you don't need a new one.

I will check it, you never know, but if it was the problem wouldn't I still have the problem even after disconnecting the tach from the MSD box. It was replaced in April 2005 so it’s a year and half old.

I can't see how your tach or your MSD would know when the car is in reverse. Is it a stick shift? Do you still have the reverse lockout on the steering column? Maybe your grounding the tach wire when you put it in reverse.

I would check the ground on the dash cluster. That one seems to cause all sorts of wierd things to happen.

Thanks for the replies, I have been out of town the last two weeks.

I Will check on dash ground.

It is an automatic.

Any other thoughts?

I second checking the neutral safety switch in the shifter and tracing it's wiring for unintentional grounding. When I took my shifter apart the wires to the neutral safety switch had rubbed off the the insulation. Not sure why a short there would kill the car, but I'd check it I guess.