MSD into a '69 911S

[Tspringer]

Well, I gave up on getting the stock CD system to ever work again on my car. It has wiring that matches none of the various diagrams I have found and studied.... all supposedly "factory".

My car has a 2.7RS spec engine. The ignition wiring seems to partly use the stock '69 stuff, but is apparently "custom" in other ways.

I installed the MSD unit today with the MSD blaster 2 coil. I did not replace the ignition wires.

I wired the MSD up exactly as was suggested in this thread by Joe911:

MSD wiring advice (connectors)

I began attempting to start the car. After several attempts, the car suddenly fired! For one brief instant I heard that wonderful BLAAAAT from the Dansk SS sport muffler..... and then it died.

No attempt to restart yielded any fruit. I removed one spark plug lead, attached it to a spare plug and grounded it and then tried the starter again to see if it was getting spark. Nope. No spark.

Given the history of this car.... its proven possession by demons and stong propensity for every worst case scenario possible being a foregone conclusion..... I figure the MSD unit is now somehow fried and worthless.

Several Questions:

1. Does anyone actually know how to wire an MSD into an early car successfully?
2. Is it mandatory that the tach be sent out for a rebuild to work with the MSD?
3. How can I test to confirm a fried MSD unit?


Notes on the wiring in my car: The CD unit plug has 2 black leads coming out of it together. I have the white wire from the MDS plugged in here. One of these black wires runs to the dizzy, the other runs directly to what I believe is the switching SCR. There is no ballast resistor.


Thanks for the help....


Terry

[sundaypunch]

I can't help you specifically - I'm assuming you've already done some searches? My guess is that you will need the tach adapter at a minimum.

I do have a few links to MSD installation threads that I've bookmarked-

Ignition - MSD Time
MSD wiring advice needed (connectors)
MSD..Yes or No?.....

[RoninLB]

I started from zero and installed a seperate MSD harness. remove and save the old.

I guess you have points.. easy install.

there should be a MSD check instructions in the manual.

I use the starter main feed for MSD power. I guess you used the inner left fender ground lug. make the old lug and tub contact area super clean.

[Tspringer]

I used the starter for the main power lead. I used one of the attachment points for the old CD box (which I have removed) as the main ground.

I have the white wire from the MSD plugged into the original CD plug mating up with the two black wires that share a spot and the small red wire from the MSD plugged into the red spot on the original CD plug. Then other MSD wires go to the coil. The purple and black tach wire is plugged into the side of the MSD.

Should run..... I expected no tach signal until I either get the adaptor or have the tach rebuilt....

I traced the wires from the CD plug. The red one just runs over to the fuse board and is ignition switched. The split blacks ones have one running to the points on the dizzy and the other running over to what I think is the SCR? Its definitely not a ballast resistor, looks like some sort of relay thing. I am going to next try not plugging into the old CD plug. I will run the red wire straight to the switched fuse panel and the white wire directly to the dizzy. Who knows... I may get lucky!

I just want the stupid thing to run. I hope to have more time to mess with it tonight.


Terry

[jstobo]

You may have fried your MSD unit. The white wire in the MSD is just a signal gound wire. When the points open the ground is broken and sends the signal to the MSD unit to fire. In you normal CdI unit that black wire has 12 volts on it. When the points open the points spark, thats why they wear out. In a proper MSD the points should last forever because of no current. Now the SCR (if I remember correctly has twelve volts going to it so you put 12 volts on the white wire ground. It may be okay since the tach adapter is essientially a transformer to supply power anyway. To check MSD unit, power up then use the white wire to touch a gounded spot on body and when you lift up you should see spark from coil. Instructions are in MSD manuel.

[Early_S_Man]

Terry,

If you are thinking that a ballast unit is a simple, conventional, power resistor, WRONG!!! As I already pointed out in your previous thread ... the #10 'SCR thingie' in the SL33 diagram is actually the ballast unit, a 3-terminal Voltage divider circuit ... your tach would NEVER have worked with out a functional ballast unit in the circuit!

[Lorenfb]

You should have determined the real problem before buying another ignition
unit. Now you have two potential problems to resolve.

The Bosch CDI setup is very very simple to troubleshoot. Also, Bosch units are
very reliable. You just have two inputs; the points (on/off) and +12 volts. The coils
rarely ever fail.

[Tspringer]

Well it wasnt so simple for me to troubleshoot. The wiring diagrams show 2 wires into the SCR.... the unit on my car has 5 wires going in and they dont match all in color. The red/white wire did not exist. There was another solid red wire, clearly a recent development, running from the coil to a rear connector and held in place with tar. When the wires dont match up in number or color or location.... it makes it a bit tough to troubleshoot.

Besides, an MSD setup was on the eventual list anyhow. I had just skipped it for now because I wanted the car running sooner.

Warren..... I know. Trouble is, the "SCR thingie" as installed on my car is nota 3 wire thing. It has 5 wires. There is no 3 wire unit there. On the old '69 911S panel and wiring from a different car I have that was parted out.... I see what its supposed to look like. My car has been modified at some point. The problem with getting the CD to work was figuring out after the fact exactly how it had all been rigged up. I just didnt feel like a big reverse engineering project. Now it looks like I will have one anyhow.

I'll test the MSD later today, but given this car I would lay a wager its fried. I even said to myself before trying to start it: "I would bet $100 this thing wont run and in fact will fry the new MSD box instead". Still.... after triple checking it was wired correctly as far as I could tell and as others here have apparently done it.

jstobo..... YOu are correct the black wire sent power to the coil. However, this power came from the CD box. With the CD box out of the loop, I didnt think this wire would have power? Unless power was flowing from the SCR to the CD box and not the other way around?


Terry

[jgporsche]

Had the same problem. I forgot to cut the 6cylinder/8cylinder wire on side of MSD box. Car ran, but poorly. After correcting that approx. 3 months later it died. Was not in warranty, sent to MSD in TX, they returned it and called to let me know it was fixed. All at no charge. I heard the 6AL may have had an inherent problem. Once fixed there as reliable as the factory unit. (Know of a lot of 6A units out there) The troubleshooting guide from MSD website pin-pointed the unit easily. Good Luck!

[Tspringer]

Well, I have been messing with it some more.....

I re-routed the white MSD wire away from the old CD plug and instead wired it directly to the distributor points. I left the red MSD wire attached to the old CD plug. After testing this red connection multiple times, it is working perfectly, hot with the key at 12 volts. I doubled checked that only the red cylinder wire was cut, so it is set for a 6 cylinder. The 7000rpm rev limit plug is in place. The MSD has good ground.

So, I went to fire it up. BLLLAAAAAAAAAAAAAM Bam. Fired right up, ran for 2 secs and then shut off. Again, no attempt at restarting yielded anything further.

So I tested the MSD for spark: took the coil wire off the distributor and taped it 1/2 inch from ground. Then with the key on I touched the white MSD wire to ground.... BIG spark from the coil wire. So.... the MSD appears to be producting a spark.

I hook it all back up, and try to fire it again. Nada.

So I remove one of the spark plug leads, install and old spare plug into it and ground the plug against hte engine with aligator clips. My wife turns the key and motor..... no spark at the plug.

WTF?

This car ran like a champ when I removed the engine to paint and detail the engine bay. I did nothing to the engine other than clean it while it was out.

Anyone in the Atlanta area reading this: know of any good early 911 experts in town? I know of one guy, but he is booked solid until late August. Everyone else I have spoken with is totally clueless about MFI.

I dont know what this problem could be at this point. Fuel related? MSD? Distributor? All 3 ? Usually when the car fires at first but then dies, it indicates a fuel delivery problem. In this case though I just dont know.

What to try next ?

Terry

[Andy Ring]

Seems to me you have to be more disciplined in your approach. If you have no spark, then why delve into it being a fuel problem? Fix one thing at a time--you may have more than one problem, but you have to fix one before you move on to the next.

I installed an MSD into my 69 911T which was totalled f'd up when I bought it. Eventually I got it to work. I had thought I had fried my MSD too, but I followed the MSD diagnostic instructions and it proved that the MSD was still good. A couple questions: do you have a condensor attached to your distributor? MSD will fry the condensor--causing no spark condition--thats what happend to me until I removed my condensor. The only other advice I have is not to worry about the tach until your car is running. I got my car running with crazy tach. Then I bought the tach adaptor and it fixed the tach--but had no effect on actual performance on car/idle, etc.

[Tspringer]

Andy....

Im not tracking fuel problems as yet. I started too since I had tested the MSD for spark and it had spark from the main coil wire, but after testing for spark at an actual plug wire end and failing Im back to square one..... an MSD or ignition related problem.

No condensor on the distributor. All the wiring appears correct. I dont have the faintest clue what could be wrong at this point, so not much additional testing to be done.

Im not sweating the tach. I have a spare that I am going to send out to be rebuilt into "MSD friendly" specs. It wont work when it comes back.... but at least that plan puts the problem out of mind for several weeks.

I definitely quit for the night though. My passionate hatred of this car continues to know no bounds. I fantasize about parting it out and having the empty shell crushed.... sort a "drawn and quartered" treatment for a car. If I could find a really nice, turn key and track ready R gruppe style early car for sale.... I would buy it and just put this minion of satan in Loooooooong term storage.

Oh well.... nothing to do but look forward to more torture tomorrow



Terry

[Andy Ring]

My advice is to call MSD as the next step. I was sure I had fried my MSD and they told how to test the unit--can't remember the details now--and it tested out fine. Try it tomorrow. When I called, I was connected to a human within the first minute. I bought my MSD used on ebay, so I wasn't expecting much help from MSD. BTW, when I finally got it working, it really helped my car at low RPM's, so don't give up.

[Early_S_Man]

Terry,

I think Andy nailed it, spot on ...

Besides hating the car ... you also, apparently, hate to do logical troubleshooting or follow simple instructions from Bosch on how to Bench test the CDI unit!

You continue to complain about the wiring modifications as if they are cast in stone!!! If the Ballast Unit isn't the correct unit or wired correctly, disconnection would be the logical step in troubleshooting ... not just continuing to whine about it!

If you have spark at the coil, but not at spark plug ... then it is a simple process to narrow down the problem to rotor, cap, or ignition wires!!! So, why are you continuing to expect readers of this board to come up with ESP answers to your self-created demon?

At this point ... I suggest you kill all of the emotional response to the presumed 'demon' in your posts, and give it a rest for a while. I have seen no evidence that your original CDI unit was bad, and you haven't provided ANY test results to prove it, or justify installing an MSD. You said the engine was running fine before being pulled ... so just what makes you think the Bosch CDI suffers from failures just sitting in a garage or driveway??? If you are the person who pulled and reinstalled the engine, then YOU are the cause of the current problem ... not some previous mechanic or owner!

[Tspringer]

Warren,

Sorry my posts have riled you up so much.

As I said before.... there is NO ballast resistor that I can find on the car period. I have the entire rear electrical panel from a different '69 911S that was parted out. On that panel, the SCR has below it a 3 pin ballast unit..... on the panel in the car there is no such unit. Its pretty tough to disconnect wires from a part that does not apparently exist....

I did not want to go to great lengths to test and repair the Bosche CD unit because installing an MSD setup was on my list of pending upgrades anyhow. Why spend lots of time figuring out the Bosche wiring and issues if I was planning on switching to MSD within a few months anyhow? I didnt realise I needed to "justify" the decision to upgrade to an MSD. I have installed MSD units previously on an Alfa GTV and Ferrari 308 and my Daytona runs dual MSDs. I did not "justify" any of these installs to anyone that I can recall.

You say that since I have spark at the coil but not at the plugs its a simple job to narrow it down. Im not so sure. The car ran fine before all this.... and I have not changed or messed with the cap,points, rotor or wires. Also.... in some MSD wiring instructions people have said a diode is required in line to the points. Others say this is not the case. Some say the tach adaptor is required for the MSD to work at all, others apparently dont think so. Some indicate a ballast resistor must be incorporated into the wiring of the MSD.... but the MSD instructions specifically say otherwise. I dont see it as just a simple thing.

I never blamed any previous mechanics for creating this problem. I didnt know blame was involved. There is just a problem that I am trying to fix. Did I cause the problem? Sure, why not. What difference does it make?

I never asked anyone to use ESP to come up with an answer to a self created problem. Specifically... I asked if anyone knew exactly how an MSD unit is supposed to be wired into a 1969 911S.

My emotional irrationality on this car at this point is driven by the absolutely freaky nature of how this restoration has gone. It has me thinking..... seriously. Close calls with a black widow spider, rust in extremely odd places, impossible to disassemble suspension parts, vanishing parts, wrong parts being shipped... 3 times in a row, parts not fitting, basically every conceivable problem that could be encountered has been. I have restored lots of cars, but never experienced anything like this beast. I hope when/if it finally does run and is complete it drives great and gives me no problems, then all will be forgiven and forgotten.

At this point I am really wondering about the diode. The MSD will fire a spark from the coil, but not the plugs. I suspect the signal coming from the points is somehow not enough to trigger the MSD. Perhaps this diode will assist with this?

I will also call the MSD folks tech support.

Thanks for the help,



Terry

[Andy Ring]

From the MSD website (have you followed these steps?):


White Wire Trigger:
If you are using the White wire (points or electronic amplifier) of the MSD to trigger the ignition, follow these steps.

1. Make sure the ignition switch is in the Off position.

2. Remove the coil wire from the distributor cap and position the terminal so it is approximately 1/2" from a good ground.

3. Disconnect the MSD White wire from the distributor points or the ignition amplifier.

4. Turn the ignition to the On position. DO NOT CRANK THE ENGINE.

5. Tap the White wire to ground several times. Each time the wire is pulled away from ground a spark should jump from the coil wire to ground. If spark is present, the ignition is working properly.

If there is no spark:

A. Inspect all of the wiring.

B. Substitute another coil and test again. If there is now spark, the coil is at fault.

C. If there is still no spark, check to make sure there is 12 volts on the small Red wire from the MSD when the key is in the On position. If 12 volts are not present, find another 12 volt source and repeat the test.

D. After inspecting the test procedures and inspecting all of the wiring, there is still no spark, the Ignition is at fault. See the Warranty and Service Page for Information.

Magnetic Pickup Trigger:
If you are using the 2-Pin Magnetic Pickup of the MSD to trigger the ignition, follow these steps.

1. Make sure the ignition switch is in the Off position.

2. Remove the coil wire from the distributor cap and position the terminal so it is approximately 1/2" from a good ground.

3. Disconnect the MSD Magnetic Pickup connector from the distributor.

4. Turn the ignition to the On position. DO NOT CRANK THE ENGINE.

5. With a small jumper wire, short the Green and Violet magnetic pickup wires together then pull the jumper off. Each time the short is removed a spark should jump If spark is present, the ignition is working properly.
If there is no spark:

A. Inspect all of the wiring.

B. Substitute another coil and test again. If there is now spark, the coil is at fault.

C. If there is still no spark, check to make sure there is 12 volts on the small Red wire from the MSD when the key is in the On position. If 12 volts are not present, find another 12 volt source and repeat the test.

D. After inspecting the test procedures and inspecting all of the wiring, there is still no spark, the Ignition is at fault. See the Warranty and Service Page for Information.

[RoninLB]

The diode is to prevent engine run on caused by voltage running backwards for the warning lamp.. this may be a problem w/ external vol reg.

You have spark from the coil but not the plugs then it's the cap, rotor, or possibly those beru spark plug connectors.
This assumes the plug wires are in order and the dizzy points connector Outside the dizzy case isn't grounding to the engine.

Unless your kaboom machine jumped a cam chain link.

and not for nothing but your post Was a little scrambled.. granted you warned us, but I sometimes have trouble multi-tasking.
Good luck.

[dhoward]

If you've installed MSD in all of those other cars, just do it the same way! It's only 4 wires for cryin' out loud! Other people have said that their MSDs have buned their rotors, something about a resistor in the rotor itself? My 69 tach didn't work with the msd. Not even with the adapter. I used one out of a 74.
There's no real signal from the points, just make/break. Make sure they are opening and closing, and the gap is set pretty close. Again, make sure the dizzy wire is not shorting to ground where it comes through the side...

[Tspringer]

Andy....

I did the tests exactly as you posted. I AM getting a very large and powerful spark from the coil to distributor wire when the white MSD trigger wire is grounded. Quite the impressive spark actually!

So, somehow this spark is not making it to the plugs. I dont see any carbon tracks or anything inside the cap or dizzy. I made sure the points are clean and gap is right.

I dont see any way the white msd wire is grounding where it attaches to the distributor, but who knows. I'll try testing for that.

I guess it could be the plug wires. I'll see if I can buy some magnecore or such locally or if they are a mail order only thing. I also have a spare cap and rotor, so I can try that as well.

Ronin.... I have no problem pleading guilty of a confusing or scrambled post, heck my brain feels scrambled at this point!

dhoward.... Ill take a closer look at the dizzy wire and test it. It does seem strange that getting this thing sorted is such a pain. When I installed the MSD onto my old 308 it was along with a single distributor conversion and was a snap. It fired and ran first try. The tach read double..... but thats always an issue going from a dual distributor setup to single.


Terry

[RoninLB]

Originally posted by Tspringer
I dont see any way the white msd wire is grounding where it attaches to the distributor, but who knows. I'll try testing for that.

what I was refering to .. is that the faston connector on the outside of the dizzy is nornally in somewhat close prox. to the engine.. It doesn't take much to accidentally push it away from the dizzy. or maybe it's loose.. it's a long shot.

PS: even if no contact with engine off the vibes from operating may cause the dirty deed.