Tachometer not working with MSD
 

OK, I had a few spare moments, and I installed an MSD 6200 finally this weekend. It was lying in the garage next to the BMW brakes I've been meaning to install for the longest. I tried four different ways to get the tach working.
1. MSD in, no tach adapter, tach wire left on (-) coil position.
Car runs great, no tach.
2. MSD in, no tach adapter, tach wire plugged into MSD tach pin
Car runs great, no tach.
3. MSD in, Tach adapter in, tach wire plugged into MSD tach pin.
Car runs great, no tach.
4. MSD in, Tach adapter in, tach wire back at (-) coil position.
Car runs great, no tach.
I'm running the Pertronix ignitor points eleminator too. Maybe that is the problem. The Monster tach is looking better and better.
I'm gonna call MSD when they open up.
Some interesting notes though. Even though the tach isn't working yet, I took it around the block a couple of times, to see if the MSD made any difference. Well the popping and sputtering I first blamed on leaking heat exchangers, and then blamed on the carbs, went away. No popping and spitting. The AF meter leaned out a lot, and I get LOUD backfiring on long over runs in gear. What'sup with that? Do I have to rejet with MSD. I didn't have to on the Vette.

Bee Jay
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No idea on the re-jetting.

On the tach, try hooking the input of the tach adaptor to the tach pin on the MSD. Then hook up the tach to the output of the adaptor. Hopefully they're labeled--or perhaps it doesn't matter which is which?

--DD

when I installed the MSD box on my race car no rejetting was required. The only wires that should be attached to the coil are two from the MSD box. The tach and/or tach adapter do not hook to the coil, at least on my setup. MSD should be able to help you if there is not a diagram available. If not, I'll look at my install diagrams tonightto see what goes where. Good luck.

I have been dealing with a similar issue. There is a specific tach adapter for VDO guages. It got my tach to work, but as the car gets warm it is hyper sensitive to voltage changes, ie the turn signals, brake lights, oil cooler fan, headlights, etc all cause it to read to low or to bounce. MSD has not been able to help other than sending me the correct adapter. Another poster to this BBS has his tach hooked up as stock and says it works fine. I tried this but did not get the same results - it didn't work at all. My ignition is the 6A model. If you find out anything, please let me know!
Thanks!
Scott S

Bee Jay,
I am running a 6-A, pertronix, and no tach adapter.
When I first installed this set up no joy and I was afraid I cooked the tach and or my pertronix. Rolled back to pertronix/no MSD to confirm tach operation. Added MSD and tach adapter, No tach. Used my dwell/tach and confirmed that - term on coil wouldn't supply tach output. Clipped dwell/tach to MSD tach adapter out, no reading. Clipped to tach out of 6-A and confirmed that my meter would read, tied down tach lead, tach worked. Tach adapter back in box on shelf. I also used the dwell/tach to confirm that the - term on the coil could no longer supply a tach signal.
Since your car is running, it seems to me that if you cant get a tach reading with a dwell/tach from the tach out of the MSD, it is possible that it could be defective.
MSD provided good tech support, but I recall having to wait for snail mail with drawing. Where did you hook up the red and black leads from the ignitor?

Carlos

Tach is Working!
 

OK, it's working. First go here: http://pertronix.com/ignition/tech/tech_assets/msd6series.JPG
Second:Splice the white wire from the tach adapter into the white wire from the MSD6 box and the black wire from the ignitor in the distributor.
Third: Splice the red wire from the tach adapter to the small red wire from the MSD6 box and the red wire from the ignitor in the disributor.
fourth: splice the 914 tach wire (black with purple stripe)into the white wire from the MSD6 box and black ignitor wire. DO NOT connect this tach wire to either the MSD tach pin or the coil (-) negative post.
You're finished. The install instructions for the tach adapter are not that clear, but there is a note pointing to the white wire that says:"if separate, splice in tach wire" That was meant for us. I did try the tach wire connected to the white MSD wire, with no tach adapter. The tach did not work.
The weekend is gone, and I have to travel to Seattle for the rest of the week, so I'll make all of this splicing neat, and take a picture next week. I won't be able to drive the 914 for at least a week. It's gotta be road worthy by the Don and Glenn Swap meet. When is it now?
Bee Jay

Bee Jay, I strongly recommend you hook things up with a set of spade terminals, Molex connectors, Weatherpak connectors, or some other kind of "quick-disconnect". A permanent splice could make it a real PITA if you ever have to remove some part of this system for diagnostic purposes, or to get access to something else, or whatever.

The "splice into here" phrase kinda makes me nervous. It implies permanence to me...

--DD

Nope, you are right. I've learned on this car, you have to be able to easily unplug stuff to trouble shoot, or limp home. I will use terminals so that I can unplug the tach adapter, or MSD, or both, at any time, and drive home. I was splicing last night just to figure out how to make it work. When I get back to Lompoc, I will find a spot to mount the tach adapter, route the wires, and make it nice and neat. Thanks for looking out.
Bee Jay