MSD no spark issues

[SeeDub_17]

Hello Realm’ers.
Here to pick your brains again.
Having some issues trying to get my project running.
Installed a brand new MSD system. Can’t seem to get spark at the spark plugs
Have 12v power at the box, tested the MSD coil and it seems to check out. Plug wires are Al brand new and have the correct amount of ohms per foot in them. If I pull the coil wire off the distributor and ground it out with a screw driver to something I can get spark at that wire but nothing from distributor out.
I am running a matchbox dizzy. My z guru guy/engine builder Reg Sumaru said to pull the matchbox module off the distributor and connect the MSD directly to it that way. Still nothing.


Anyone have any insight they can share?

[Not Now]

If you've got spark from the coil wire to the chassis when you turn over the engine, then it sounds like your MSD system is working. I'd start looking to see if your cap and rotor are OK.

[510rob]

make sure that silly little nub of carbon is in the cap; there is a little carbon contact to transfer 'spark' from the center contact to the rotor and if that is missing for some strange reason, your engine will act goofy. Jeff told me he acquired a perfectly good motor that someone gave up on because it was missing that tiny carbon pill. What a score, what a shame.

[bertvorgon]

Yes on the carbon "pin" in the cap.

There is a small spring behind that and occasionally I can fire the carbon pin onto the floor when you might not notice.

I just went through that as I was figuring out an issue with my car and made sure it had NOT done that during my bug sorting, as that did get me many years ago.

[datzenmike]

Distributor may be timed with the rotor between plug wires on the cap.

Set engine to TDC compression stroke on #1.
Remove distributor from the timing cover and look.

You should see this from...



Take note of the large and small side the half moons are on. If you have this, above, then you should be able to get spark and adjust for timing. If you don't, you'll have to drop the oil pump turn the drive spindle and insert it back until you do.

The matchbox is far and away more than you will ever need for ignition spark. They were used on the six cylinder 280z and zx and at red line, about 7,600 RPMs that's 11,400 RPM on a 4 cylinder.

[SeeDub_17]

Thanks for the info.

I'll look into the rotor and cap. Both are brand new out of the box, the entire car is basically a ground up rebuild. Its never started, I was almost there. I guess there could be a chance that I have the wrong cap and rotor?

I believe the distributor gear is sitting currently the way you have it in your picture @datzenmike. At TDC number one cylinder is about where you have "Small Side" written. Wouldn't you still get spark from a sparkplug regardless if the distributor was180 Out. It for sure wouldn't run properly as everything is firing at the wrong time. In my case I have zero spark at any of the plugs in its current state.

Side Note, Its impossible to turn this engine over with a socket on the crank. There is no room between the ATI Damper and the front lower rad support. I can get a socket on the crank bolt but no way of getting a wrench on the socket. Need to make a tool or something for this to work.

[Not Now]

If everything is working correctly, but you are 180 out, you should still get spark at you spark plug.

[datzenmike]

Disconnect anything to do with that MSG unit and get the stock matchbox set up working first.

Turn ignition on. Make a jumper and briefly ground the coil negative terminal and release it. It should spark on release if there is power. Does it?

[bertvorgon]

I concur with Mike.

As much as it is cool to say I have an MSD and can weld with it, that matchbox does an amazing job.

I run 12-14 PSI boost on a 10:50 motor and spin that thing to 7,500 - 8,000 and have NEVER missed a beat.

And that is with some full throttle 5th gear pulls to redline.

Hope you get it figured out one way or another, things like this are frustrating as hell.

[SeeDub_17]

Morning,

Update from cold snowy Edmonton. Took out the matchbox distributor and took it to a friends shop to test on his car. He has a vintage 510 race car with basically the same components as I do. We wired up the dizzy in his car and turned it by hand. We get spark on his car, but very weak and inconsistent. Reg's explanation was that the distributor that I have has shaft play in it and that's the reason for the crappy spark. Does not explain why I cant get spark on my car with the same setup. Back to trying to find a donor one to replace mine or try and rebuild it somehow.

As a plan B, I had a points style distributor and a Petronix kit at home in a box. Assembled that and tested it on my car. I got one hell of a shock from the distributor as I spun it by hand while looking for spark. Guess I didn't have it completely grounded on the car for this process and got zapped. That being said it seems like the distributor has power if I'm getting shocked like that.
Being a little gun shy to try it again, I installed it and wired it up, still no spark. Went back to the MSD manual to triple check my wiring. Made some changes now that I'm running the petronix kit from what I had before. Wired it up the way that the manual says for that kit and still no spark.

Completely stumped as to what the heck is going on with this. Coil has power, distributor has power. NO SPARK!

[Not Now]

To clarify, are you saying you don't have spark coming off your coil wire or just off you spark plugs?

[SeeDub_17]

Hey @not now,

I've tested and I have spark at the coil. Popped the coil wire off the top of the distributor stuck a screw driver in it, grounded it against the engine and I get spark jumping from the screw driver shaft to the engine. It seems like the distributor is not transferring the spark to the plugs.
If I hook it all up and stick a plug into the end of a plug wire the spark plug does not fire.

[Not Now]

Copy, it sounds like the system is working, just not sending the spark from the distributor. At this point that only leaves the cap and rotor, plug wires, or the actual spark plugs. I have seen bad spark plugs out of the box, but I doubt all 4 would be bad. Do you have a good ground strap from the engine to the chassis? I typically run a ground strap from the engine to the chassis, one from the battery to the chassis, and one from the battery directly to the engine. May be overkill, but it seems to help with all the electrical systems in the car.

[SeeDub_17]

Brand new plugs and MSD wires. Meter'd out the wires and they are all 40-50ohms per foot as per specifications.
Engine has a ground strap from the block to the chassis. Welding wire. put a multi meter on it and it is grounded properly.
Battery has ground from it to chassis in the trunk. Same welding wire. put a multi meter on it and it is grounded properly.
Battery to starter is all new wiring. Welding wire.
Matchbox dizzy has a brand new cap and rotor on it.

[Not Now]

I do wiring for a living and I can't tell you how many times a mechanic has asked me for help with something, I tell him where to check, he says he did that already, then I go out and check where I just told him to check and that's the problem. We have a saying, "trust but verify". I suspect your ground is good because you were getting spark from your coil to the engine block, but just to be 100% certain, could you disconnect the positive side of your battery and leave the negative side hooked up? Then measure the ohms from the negative post of your battery directly to the engine block? Multi meters very in quality, especially when measuring ohms, but you want to see somewhere around .1 to .5 ohms. If that checks out, then you're going to have to start throwing parts at it. I'd try a different cap and rotor first, then plug wires, and finally a different distributor. I know all your parts are new, but I can't tell you how many times I've seen new parts not work, how many hours wasted trouble shooting brand new parts.