MSD Install on 911T?

[jtkkz]

Hello,

The car in question is a 1973 and a half. PORSCHE 911T CIS(K-Jetronic).
The car has 65,000 original miles. It is a using a point system, no petronix and no trigger system, just standard contact points.

I am having difficulty getting the tachometer to read correctly after having installed a MSD 6AL, MSD Tach Adapter (part # 8910)
and MSD Blaster SS coil (part # 8207) NOTE: I did not use the MSD 2 Blaster coil with ballast resistor combination.

I followed the wiring diagram according to MSD installation as stated in Project 24, page 74-75 of 101 Projects for Your Porsche 911 ( Wayne R. Demspey). Below are the exact instructions and procedures, highlighting the key points in the wiring of the MSD box.


"The thick red wire that exits the unit should be connected directly to the battery. Since this is hardly
possible with the 911 battry being in the front of the trunk, you should conect it to the large
electrical connection on the starter. This wire is connected to the battery.(checkw/voltmeter)
and should be live all the time. Make sure you disconnect the battery before unscrewing this
connection. The large black wire is a ground wire, and should be connected to one bolts that
mount the aluminum plate to the left side of the car.
There are two wires (black and orange) that exit out of the unit and are covered with a black
sheath. These are to be connected to the new Bosch blue coil that should be installed in place
of the older black one. The orange wire is connected to the positive (+) terminal of the coil,
and the black wire is connected to the negative (-) terminal.
The thinner red wire needs to be connected to a switchd voltage source. The best place to do
this is to tap into electrical connector that used to go to the CD box. Peel back of the rubber
insulation, and underneath you should find a red wire. Tap the thin red wire from the MSD unit into
red wire that comes from the CD box connector, so that you don't destry the wiring or the connector.
The white MSD wire is connected to the points if your car has them (1965-1977). Cars with
magnetic pickups us the magnetic pickup wire in the MSD unit.
The tachometer wire inside the CD box connector is black with a purple stripe down the side.
This wire needs to be connected to the tachometer output on the side of the MSD unit. In addition
the tachometer adapter from MSD needs to be installed inside the engine compartment. Simply
wire the tachometer adapter into the system as described in the MSD installation documentation.
When you are finished installing your MSD system, it's advisable to install a new cap,rotor and spark
plugs. MSD recommends that you set the gap on your spark plugs to much wider distance, in the
range of 1.27 to 1.49 millimeters, which is much larger that the factory specification of .07 + - 0.1mm.
MSD also recommends that you play around and adjust the spark plugs until you obatin the
performance that you are looking for. The recommended values are simply good starting points."


The only difference I used was framed ground vs. battery ground. I have installed numerous MSD boxes on various vehicles including Fords, GM, Datsun, etc. I have tried all possible options including using the diode connector supplied by the MSD box. I have separated the tach adapter and the coil thinking it was too close to one another (See attached pics). Separating all three made no difference in making the tach read.

My problem is, the tach does not register at all as the car revs up or idles, even after what I perceive to be correct wiring. The tach does not move as if there was no source (or signal). Prior to this, the vehicle was using a Perma Tune C911 coiless ignition and the tach worked properly. The only thing I have not used is the trigger system output connector from the MSD 6AL box. I have also used the wiring system from MSD installation point/amplifier style ignition based on page 10 of the installation instruction manual of the MSD 6AL. I have also disabled the Tach adapter but with the same results (no reading on the tach). I tried using a $40.00 Tach / Dwell/ Multi meter tester from Sears. I attached the red lead to the tach output on the MSD box (black to frame ground) and it worked fine. There were readings on the digital meter, but not on the VDO Tachometer on the car.

Any assistance, would be GREATLY appreciated. If you wish, I could call you or the fax to you the wiring diagrams used. I would like to test the tach adapter from MSD but I do not know how to test it. The picture of the VDO tach is with the engine shut off. Just wanted you to see that it's an original VDO tach. All other aspects of the car work fine. There are no grounding or poor/corroded connection issues. The car revs well and cuts off at 6,000 rpm (like it suppose to) due to the MSD rev limiter. But the tach remain at zero. Brand New Cap, rotor, spark plug wires have been installed.

Thank You for your comments/help and replys

[jtkkz]

Sorry I did not mean to post in a 914 tech bulletin. I meant to post on a 911 bulletin.

[red-beard]

Well, It's not a problem....I have your answer!

I installed an MSD into my factory 914/6. And I used the Tach adapter. No end of problems. Anyway, the final result, I sent the tach off to North Hollywood Speedo and they rebuilt the inside and now the tach works perfectly.

Checkout:

MSD Installion and Tach woes

James