My new MSD won't talk to my analog dizzy?

[godfearingman]

Hi Rod here with 1977 911s targa. Been having trouble firing up the car after engine rebuild. At the end of my rope and time took, I it to the local Porsche dealership and spoke to the head technician who said that it appears my broken Permatune replacement, an MSD 6A, cannot talk to my dizzy. He says he thinks its because my dizzy is analog.

Anyone ever hear this? Ive heard many success stories regarding MSD and 911's and a few horror stories about some 911's that just don't like the msd. Am I just one of those unlucky bastards?

I'm taking any suggestions on how to fix this. Thank you for your time and thought.

I read ya'll like pics of subject matter when soliciting help.

Rod

[K Sykes]

Not sure what he means by analog? Do you have points or a magnetic pickup? There are different ways to wire the MSD depending on which you have. The only other issue is a tach signal - sometimes you need a tach adaptor. I can't speak to whether it's the tach or the distributor that drives the need for an adaptor.

[moneymanager]

Call MSD and ask them. Their tech guys are very helpful. Be prepared to tell them what you have.

[mreid]

Are you triggering via the white wire or the magnetic (paired wire) input? Also, which ever you use, the other cannot be grounded or your engine will not run.

[godfearingman]

Thank you all for your input.
Mr K- He meant that I needed a digital dizzy. I have a magnetic p/u. I took a chance and opted not to buy the tach adapter. I should have known better.
Mr Moneymanager-I will call right away.
Mr Mreid- I am triggering the the magnetic p/u wire and not using the white wire. Made sure it would not ground.
I will report back after speaking with the boys at MSD. Thank you.

[James Brown]

the magnetic pickup will work fine with the MSD, you might need a tach adapter or not, just wate till you get it fired up, more troubleshooting is needed.

[Scott S]

I just did this to my 914-6. 2.7 using the stock distributor, a pertronix and an MSD 6A. There were aboslutely no compatibility issues - it fired on the first crank.

In my opinion, you either have a bad pertronix, a bad MSD box or it is a simple wiring issue.

[Bob Kontak]

Originally Posted by Scott Schroeder

.... or it is a simple wiring issue.

I am thinking wiring issue. Take some time on your tach connections - especially your ground.

Not "dissin' you. Just a fact that fifty-million connections are effed with when you install the MSD. You can forget something.

I have the 77 US factory diagrams scanned if you are interested.

[Fastdog911]

try to hunt down bob ashlock as he sells a tach adaptor that works...

[godfearingman]

Gentlemen, thank your time never take anything personal, especially when being helped. Talked with the MSD guy and he made sure we had correct polarity. Then he asked if I performed the spark test with the msd box by itself(said it was in the accompanying paperwork) to which i answered negative. He said to do this tomorrow, it would determine if the box was at fault.
I spent the last month trouble shooting this no firing issue six ways from sunday, but now racing the clock since the car and i have a date with italy coming quick. I finally figured the porsche technician would have known and could carry me the rest of the way but now think his msd experience is lacking.
Does a wire from the msd connect directly to the black and purple tach wire? I don't believe the tach is hooked up. I am definitely interested in your diagrams Mr Kontak, Thank you. I will look for Mr Ashlock to get that tach adapter. I will report to you gentlemen tomorrow.

[Bob Kontak]

Originally Posted by godfearingman

Does a wire from the msd connect directly to the black and purple tach wire? I don't believe the tach is hooked up. I am definitely interested in your diagrams Mr Kontak,

I can confirm the black and purple wire connection in the morning - EST. Well, before noon.

PM me your e-mail re diagrams.

[Pazuzu]

1) The MSD has a tach output on the side, plug the black/purple wire right into it. On my 6420 it's opposite the side where the main wiring loom enters, I don't know about the 6425 if that's what you have.
2) AFAIK, the system will work fine even if that is not plugged in.
3) Does the engine cough and spit and not fire up? Switch the green and purple lines to the dizzy cable, the MSD instructions are switched for our cars.

[T77911S]

the tach worked fine with my MSD with no adapter, but then i had points. if your car/tach originaly had points, you dont need the adapter.

if you are using any exsisting wiring that was original, that could be a problem. those wires get brittle and break/short.
the MSD also requires a dedicated power source along with the one from the ignition switch. i ran a wire to the positive on the starter.

make sure the 2 wires from the MSD to the coil go directly to the coil. again, do not tie into any old wiring.

get it running, then worry about the tach.

[Bob Kontak]

Originally Posted by T77911S

the MSD also requires a dedicated power source along with the one from the ignition switch. i ran a wire to the positive on the starter.

Vincent Hill was pulling his hair out. I think this is essentially what was wrong. Incorrect wiring - think he did not feed the box with power.

Start at the end of the thread.

I am Stuck, Replaced the CDI & Coil & Still No Spark!

[JohnJL]

If you are in a time crunch, which it sounds like you are, ignore the tach issues. Those are a distraction. The engine should fire and run normally regardless of your tach, working, broken, incompatable, or disconnected.

[JohnJL]

You don't list a location in your profile. You may need a friendly local hand. Near vancouver or toronto?

[jpnovak]

The car has TX plates. If you are in Austin let me know.

[godfearingman]

Apologize about the location listing in profile. In military and my bosses are paranoid about that. It's Fayetteville, NC, 28305.

Im working on getting a tach adapter, either from MSD or from Mr Bob Ashlock. Anybody have his contact?
The Porsche tech not yet gotten back to me on whether the box passed the test. He is also taking the advice ive passed on to him from you guys: rechecking connections, grounds, wiring.

Mr Kontak-Ill read that article as soon as i send this update. Thank you.

[7T7911s]

I recently installed the digital 6AL in my 77.
everything worked fine I could get a spark by tapping the white lead that goes to the
dizzy, but could not get the darn thing to start. I found out I had wired the hot lead and the ground both to the starter (I assumed a good location) Not so. Once I moved the ground to a point on the fan shroud, she runs good. still haven't fixed the tach yet, but I'll follow this post and see what happens.
kenny

[Fastdog911]

ratech@pacbell.net for Bob Ashlock... had same issues.. his part got my tach working in 5 minutes