Distributor

[Maintenanceman]

Ok I wasnt sure where to post this so Ill post it here. I have a Sunpro Tachometer hooked up in my truck. As far as I know the distributor is not aftermarket. The tachometer quit working SO I assumed that it was the tach. I figured if the hook up on the distributor wasnt working then the truck wouldnt be getting fire so I bought a new Tachometer and put it on there. Same problem. The lights come on but no RPM reading. So, now my question is If its the distributor? would I not notice a difference int he truck running or cranking for that matter? The truck backfires back up through the carburetor alot but I think it needs a rebuild (or a replacement, which it should be getting in the VERY near future = Holley Street Avenger 670 along with some other goodies) or the timing is off a bit. Also would a new cap fix my tach problem?

Thanks,
Ben

[Russ130]

Check your tach wire for continuity. If you have the in cap HEI ignition I doubt you have a problem with the distributor. You probably have a short in the tach wire. The tach wire reads the ground pulses on that system so to not have a ground would mean no run. The only other thing it could be is the wire inside the coil cover is broken between the tach lug and the pickup lug. Pull the tach lead off and use a mirror to make sure there is a blade for the tach connector to actually slide onto. As far as back firing goes that would definitely mean a tune up is in order and possibly a new timing chain. The Street Avenger 670 is a nice set up you will be happy with too.

[Maintenanceman]

Well I checked the wire with my multimeter for continuity and no problem. It rang out fine but Ill check the lugs. thanks!

[Maintenanceman]

Completely replaced the wire leading from the tach and double checked the lugs. Broken wires can be tricky, I checked it with my meter and it never showed that there was a broken wire but I replaced it anyway and now it works! thanks!

[choptop]

One thing I learned years ago the hard way, is sometimes you can get continuity, but  it wont carry a load.The break acts like a circuit breaker. The load makes it show, which is why I use a megger to test generator windings.Glad you found it.