Ignition Troubleshooting Advice-MSD Install

[holtjv]

Hey there--I've done quite a bit of searching for this trouble but kind of need some advice to help put all the fragmentary information together, if that makes any sense to you.

Here are the conditions prior to install of msd 6a + blaster coil:

1. cdi getting 12volts, whines with ignition
2. no spark at coil
3. ungo (?) alarm installed but has never given me any trouble

Conditions after install of msd and new coil:

1. the same as before, although I've yet to check power to the msd which I'll do tonight--no spark at the coil
2. negative terminal onto the battery no longer chirps the alarm as before--initially thought this could be a good thing but admittedly have not researched how to uninstall the alarm.

There's a slight chance I've messed up the msd-cdi female plug wiring, but don't think so. I've referenced 3 threads which shows the wiring (I used the spade connectors into the plug) and pulled down the rubber covering to see how the connectors were mapped to the wires--think I'm solid on that but could be wrong. I know I also need to check voltage at the starter but that seemed fairly straightforward.

So it appears to me that the failure is between the msd and the coil--does that make sense? I am an electrical newbie newly armed with a digital multimeter--can you please direct me how to troubleshoot?

Many thanks...need to get the car on the road this week as nascar weekend is coming up and no work during the weekend will set me back another week--jonesing for the car.

Jack

[RoninLB]

i removed factory ignition harness and used new self made harness.

[holtjv]

Ron, given the state of the current harness, which looks like a dirty, offensive, birdsnest, I'd love to make my own but of course would be intimidated a bit by the effort without careful instruction.

I saw with envy your setup--very impressive--do you cover it in some manner or are the elements exposed to the weather?

Let me search for a thread from you on this to see if you notated it....thanks

[RoninLB]

ignition wiring is uncomplicated and is a seperate system from rest of car besides tach, ignition turn on/off, and main power from starter lug.

i used www.waytekwire.com double wall shrink tube to enclose MSD ignition wiring.

[holtjv]

Ok, I have power to the msd unit, power to the starter but again, no spark.

So how do I check the power to the coil (correctly)? I remember reading a thread which stated not to connect anything to the + terminal of the coil.

Thanks..Jack

[RoninLB]

MSD install instructions "checking for spark"

i have no experience with the 1978 and later distributors.

[holtjv]

Hmm. Went through the instructions and no spark from the MSD to the coil. FAI, the process is simple:

1. disconnect wire from distributor, place 1/2 inch from a ground
2. turn ignition on, do not crank
3. tap white wire to ground, spark should occur from the coil-to-distributor ignition wire

I guess the next logical step is to re-wire as per 101 and not using the 6pin from the CDI (unless anyone else has any brighter ideas).

Jack

[holtjv]

Might also yank the ungo alarm crap--I believe it cuts power to the fuel pump, right? I was getting screaming from the injectors though and, of course, no spark. Does the ungo alarm hit the ignition system?

Anyone?

[CT944]

remove the Ungo. it is useless anyway for a thief these days and will narrow down your issue. i had one on my 944, and i took it out when I had a 'no spark' problem. my issue turned out to be the DME.

[vash]

i think in the MSD instructions; the next step is to check the coil. borrow one.

[holtjv]

Originally Posted by vash

i think in the MSD instructions; the next step is to check the coil. borrow one.

You're right, the next step is to try a different coil. And yet, I replaced the coil with a new blaster (because I originally suspected my original coil). So I think it's either the wiring to the coil from the msd or the alarm. I'll yank the alarm first b/c it's an approach I haven't tried yet. If that doesn't work, then I'll rewire the msd using Wayne's 101 instructions. If that doesn't work, then I'll have a beer or 20 because by then it will be a weekend at the racetrack with the guys.

Jack

[RoninLB]

Originally Posted by holtjv

Hmm. Went through the instructions and no spark from the MSD to the coil. FAI, the process is simple:

3. tap white wire to ground, spark should occur from the coil-to-distributor ignition wire

notice #5 of magnetic pickup

[RoninLB]

group pelicanhead reply burried



"The 3.0's green wire from the distributer is coaxial, it has a
sheath and a core wire, these connect to the violet and green wires
of the MSD..also, The white wire of the MSD is not used but can be
connected with a normally open switch to ground as a kill/anti theft
switch..also, The Grren wire from the distibutor gos to the Grren
wire on the MSD and the outer shield part of the green wire goes to
the purple lead."

[RoninLB]

Originally Posted by holtjv

I saw with envy your setup--very impressive--do you cover it in some manner or are the elements exposed to the weather?

dielectric paste on soldered connections and it's waterproof.

[holtjv]

Originally Posted by RoninLB

group pelicanhead reply burried



"The 3.0's green wire from the distributer is coaxial, it has a
sheath and a core wire, these connect to the violet and green wires
of the MSD..also, The white wire of the MSD is not used but can be
connected with a normally open switch to ground as a kill/anti theft
switch..also, The Grren wire from the distibutor gos to the Grren
wire on the MSD and the outer shield part of the green wire goes to
the purple lead."

Thanks, saw this as the alternate method of checking for spark from the msd. Unless I'm missing your point, which is entirely and probably possible.

Will hope to rip out senor Ungo this evening, last rites being read as we speak.

Jack

[holtjv]

Oh and you've also reminded me to go ahead and buy a new distributor 'green' wire, while I'm at it. Stupidly expensive, iirc.

[vash]

actually to test the MSD you jump and un?-jump the green and purple wire, right?

[holtjv]

Originally Posted by vash

actually to test the MSD you jump and un?-jump the green and purple wire, right?

According to their userguide you can either jump the green and violet wires or do the white wire tapping trick. I think the white wire is used for points distributors and thus may not be as accessible as jumping the pickup wires, which is why they offer the two choices. But I'm sort of talking out of the left side of my mouth...

Here is the link to the 6a with the downloadable instructions and here are the relevant parts regarding testing for spark:
http://www.msdignition.com/ignition_4_6200.htm

[vash]

hmm. i read that as; if your car uses the trigger wires, then use the jump the green/purp wires. i did it on my car, and the unit worked.

[holtjv]

that sounds right. maybe I'll try that way just for the helluvit. My prime suspect is the alarm, though, so I wasn't that surprised it didn't work as it didn't work with the original cdi.