The weird tach problem

I have been driving my D with the new engine in it now for about a month. I had it in the beetle last time (no tach installed In da bug).

I have a tach that's over revving weirdly.

We checked it with a OLD John Deer Combine Mechanical tachometer.and confirmed it was in (NO WAY) working correct. IT's smoothly working just going way too far..

I recall someone here has a fix for this with goodies pilfered. at Radioshack . I check the knowledge section and found no postings for it.

Before! I forget it again for another week (((HELP!!!)))))

http://www.thesamba.com/vw/forum/viewtopic.php?t=352217&highlight=tach

Thanks Mike !

I'm off to Raddaddio Shack. That fix is for a Jummpy tach . I don't have that prob..I may also have to add a resister.

In a acceleration with the fully automatic it goes way over every time you floor it but the engine rpms don't change nearly that drastically.

I also noted a light tingle touching the dizzy when I was tinkering on the throttle linkage in the middle while I was upgrading that with needle bearings on the pivot lever.

It didn't kick much, but it puzzled me ..

This is the first Flame Thrower dizzy I have ever used , Its the big HEI type with the remote 3 ohm matching coil.

Everything is nearly new and looks fine. If I were to start testing it's components with a meter what should I be looking for.

My first guess is the center coil wire

Barry, run a ground wire from the distributor to the engine case, and be CERTAIN that you have a good ground strap or three to the chassis. On my Spyder, I have the battery ground cable direct to the trans, hot to the starter. I have three grounds, a 10 gauge to the frame from the battery, and two separate braided straps, one from the bellhouse and one near the tailshaft.

I have gotten zapped from a distributor that wasn't well grounded before.

Was this tach ok before, and changed with the new ignition? Pertronix has a website, it probably has troubleshooting info just like MSD and Mallory do. Start there or call their tech support people, I am sure they can help you.

On some aftermarket electronic tachs, you'll need to add in a three wire filter. ~Alan

I put a 1N4005 diode on it and Wala!.. A very simple fix for under $2 bucks. and I have a spare Diode.

So the prize goes to Mike.. Thanks Guy's!!

The diode fix (or any other fix) did not work for any of the 3 tachs I have had in my Vintage speedster. I'm on Kirks list to get a new tach from his new manufacturer as soon as they arrive.
Troy

The Chinese repro tachs are a piece of you know what....Kirk sent me another one and after it died again I sent it to North Hollywood Speedometer who did a VDO conversion to it and it's worked perfect ever since. I'd suggest that and be done with it.

Kirk also sent a replacement tach to me as well about a year ago and it has been working perfectly ever since. I guess you can get a good one and you can get a bad one---just like many things.---Jack

You're lucky; I got the shaft twice with those. But even with all that the joy I get out of my car is immeasurable.

I have you beat Richard. I've had 3 fail and I'm waiting on my 4th.
Troy

I'm knocking on wood right now. Two years almost and still ticking.


Marty

Time to check out one of these people (listed in the "Makers" section):
No. Hollywood Speedo or Palo Alto Speedo
Anyone who would accept a 4th failure has to realize that the supplied part (source) is junk! Period.

Do the VDO conversion and be done with it; that's what I say.