No spark

[dipso]

I am completely stumped. First a short history, I doubt they are related.

I put bigger venturis and jets in my PMOs. Took it for a drive and it drove great. I increased the accelerator pump volume while I was out and was test driving around. I never turned off the car while doing this.
I came home, turned off the car and went inside. Came back out later and tried to start it, but it wouldn't start. I figured I flooded it because I wasn't used to the new volume.

I let it sit for a while, then for a few days. All the while continuing trying to start it. I figured I fouled the plugs. I turned the accelerator pump volume back to where it was originally.
Friday morning I put in all new plugs, 12. Still no start, so I checked for spark. I wasn't getting spark. I thought maybe the coils were bad.
I put in 2 new coils MSD Blaster 2s yesterday. Still no spark. I pulled the MSD boxes and ran them down to a speed shop, They tested them and they both seem to work fine.
I don't know if the test included the purple and green signal wires and forgot to ask. They are closed today. I am not even sure what those do anyways.

Here is what I have checked so far.
No spark at the spark plug end.
No spark at the wire that comes out of the coil.
I took the cap off the distributor, JB Racing 12 plug, it was dirty inside so I cleaned it and checked the gap .015 at the magnetic pickups.
I have 12 volts at the wire that feeds the MSD boxes from the starter. I have 12 volts at the small red wires that go to the MSD too.
I have the white wires hooked up to a kill switch, but I disconnected them during this troubleshooting.
My MSD boxes are pigtailed to one of the pickups out of the distributor. I have tried both pickups, no start.
I checked voltage at the small red wires during cranking. 12V at on position it drops a little at cranking, but stays steady.
The engine is grounded. I know this because I use the fan shroud as a ground when I am using the multimeter.

Could both magnetic pickups go bad or could a bad cap and rotor cause no spark? I have maybe 4 or 5000 miles on the distributor. I would think i should still get spark out of the coil.

I feel like I have checked everything well, except the distributor. I figure it is not the ignition switch, because the voltage doesn't go out during cranking at the fused small red wires.
I am going to check for voltage drop at the large red feed wires from the starter right now.

I am baffled and out of ideas. The wiring inside the distributor looks pretty good. The grounds are good on the MSD boxes.

[dipso]

No significant drop or cutting out at the large red power wires.

[dipso]

I have a resistance of 441 and 439 out of the distributor magnetic pick up leads.
MSD troubleshooting page says it should be between 500 and 700.
Does this mean anything?

[mreid]

Sounds like ignition, but verify you have fuel.

Disconnect the pigtail from the JB distributor pick up lead. Connect a timing light to an ignition 12v source and ground and clip the pick up around one of your coil wires to the distributor (you should pull the fuel pump relay for this test). Turn on the ignition and insert a bent paperclip into the end of the pigtail going to the ignition boxes shorting the contacts to each other. Each time you remove the paperclip the timing light should fire. If one works, test the other. If both work, remove the cap and determine which cylinder the rotor is pointing at. Clip the timing light pick up around first the top then the bottom wire repeating the paperclip test each time. If the timing light fires each time, you have verified that the boxes, the coils, then the rotor/cap, and wires are working. If not, you know where to start looking. Good luck!

[dipso]

I haven't tried your test, but I did try the suggested MSD test.
I pulled a coil wire out of the distributor cap. Stuck a screwdriver in the contact and placed it near a ground. I even tried it with no screwdriver.
Then I pulled the MSD lead from the pigtail. Put a paperclip in the end and shorted out the leads. It is supposed to make a spark at the unplugged coil wire to ground. It didn't do anything, no spark. The key was in the on position.
I checked voltage during this test and am showing 12 or slightly under at big red wires and small red wires.

According to MSD, that means my boxes are bad. But they supposedly ran fine when they were tested yesterday.
I am not getting any spark anywhere.
I have 12V at the white wires that go to ground, for my kill switch. But like i said, they are disconnected from the switch. It sure does sound like something is just grounded out.

[mreid]

Did you disturb the heavy black ground wires that go to the MSD boxes? You need ground also.

Try the MSD test but use the screwdriver in the coil wire (disconnect at the cap).

Did you do any welding on the car? Change your exhaust or anything like that?

[dipso]

When I reinstalled the boxes, after taking them out to be tested, I cleaned the ground terminals.
I did the test with the coil wire pulled out of the cap.

No welding, no anything. It is very strange that both would of gone out. That is why i keep thinking it has to be a single thing somewhere? Bad ground, bad distributor, bad ignition.

[mreid]

Do your MSD boxes have the red LEDs or are they the old style?

It does sound like both MSD boxes died, but strange they both went at the same time. Any voltage surges, alternator or battery issues?

[dipso]

They are the old style, no lights. But when I took them in to be tested, they showed spark.
Now when I have them back in the car, no spark. I'm thinking that when they tested them, they weren't hooked up to a distributor, just a machine. Possibly the problem lies in the signal wires.

Could it be a ground issue? Battery ground, transmission ground? Is there any chance it could be the distributor.
Could a bad distributor cause no spark at the coil? I'm out of ideas.

[fred cook]

Have you checked the coax wire that runs from the boxes to the distributor? Sounds like you have verified everything else! Maybe a connector on the MSD end has pulled loose or there is a broken wire? Good luck!

[mreid]

The paperclip test rules out the triggering side of the distributor. Here's a quick guide (assumes there is only one problem). With ignition ON (assumes triggering with green/violet):

1. Paperclip across green/violet produces spark at coil output?
Yes> dizzy module or wiring from dizzy module bad (or module gap wrong)
No> dizzy module and wiring good, see step 2

2. 12v on small and large red to MSD, ground to heavy black, white insulated from ground, and green/violet connector intact and connected to dizzy.
No> repair wiring and power source
Yes> swap in known good coil and see step 3

3. Retest, spark?
Yes> replace coil
No> inspect black and orange wire to coil, see step 4

4. Wiring to coil correct?
Yes> replace MSD box
No> repair wiring

That should do it. Seems both of your MSD boxes are bad. Stranger things have happened. Sorry about that!

[dipso]

Originally Posted by fred cook

Have you checked the coax wire that runs from the boxes to the distributor? Sounds like you have verified everything else! Maybe a connector on the MSD end has pulled loose or there is a broken wire? Good luck!

No. they are built in. Those are the wires I am suspecting or the distributor. Those are the only 2 things i cant check.
I just cleaned the ground from battery to frame, and from frame to transmission. I couldn't get access to the transmission bolt, due to the crossmember that holds the transmission. But it looks tight.

I don't know how to test the green purple wires or the distributor.

[mreid]

You pretty much ruled out the distributor when the paperclip test didn't work.

Start where the pigtail plugs into one of the JB distributor leads. That pigtail is about 6 inches long with a plug connected to each green/violet wire pair to your two MSD boxes. Follow each wire back towards the MSD box and you should find a second plug about 4 inches from the boxes. Make sure all five of these connections are connected and tight.

[dipso]

Originally Posted by mreid

The paperclip test rules out the triggering side of the distributor. Here's a quick guide (assumes there is only one problem). With ignition ON (assumes triggering with green/violet):

1. Paperclip across green/violet produces spark at coil output?
Yes> dizzy module or wiring from dizzy module bad (or module gap wrong)
No> dizzy module and wiring good, see step 2

2. 12v on small and large red to MSD, ground to heavy black, white insulated from ground, and green/violet connector intact and connected to dizzy.
No> repair wiring and power source
Yes> swap in known good coil and see step 3

3. Retest, spark?
Yes> replace coil
No> inspect black and orange wire to coil, see step 4

4. Wiring to coil correct?
Yes> replace MSD box
No> repair wiring

That should do it. Seems both of your MSD boxes are bad. Stranger things have happened. Sorry about that!

With key off, I get 0 at the small red wires and 12 at the large red wires. 0 at the coils.
With key on, I get 12 at the small red wires, 12 at the large red wires and .18 at the coils positive side, .18 at the coils negative side.


If I need new boxes, I need new boxes. It's not a big deal, I would like the ones with the lights. But I don't want to buy new ones if I don't need them and have it turn out to be the distributor instead.

Can you think of any other tests with the volt meter I could try? And yes I have checked those connections about 100 times.

[mreid]

You already isolated the distributor. When you triggered the box with the paperclip (key on) and the coil output near ground, you didn't get a spark. This method eliminates the distributor (both trigger and high voltage distribution) and it still didn't work.

Try this same test, but use the white wire. Each time you touch it to ground it will spark when you then lift it. This will help confirm your problem.

[dipso]

Genius! That is the first time I saw spark.
I pulled one of the center plug wires and held it to the fan housing. Touched the white wires to ground and SNAP, ouch. Was a little more careful the second time and plenty of spark.
That's great!
So now I can assume there is a problem where? The green and purple pick up wires out of the MSD box? Because if the black and orange wires to the coil were bad, or the MSD wasn't providing spark I wouldn't be getting spark, correct?

Interesting. That's awesome.

[dipso]

I just had an idea. I was wondering if maybe the break in the wires was in that long green and purple connector wire between the distributor pick ups and the MSD connectors.
I removed them and tested them with a multimeter. No break, so the bad area must be inside the MSD.

But while I was at it I put the tester on the coil connections. If I put the ohmmeter on the positive terminal and the fan shroud, it beeps. If I put the ohmmeter on the negative terminal and the fan shroud it beeps. If I put the tester from positive to negative it beeps.
Is this normal? Seems like my MSD boxes are fried.
I'm not very experienced with an ohmmeter, but I am trying to learn.

[mreid]

That's correct, your problem is in the magnetic pickup amplifier in the MSD boxes. You can try one more test. Disconnect the green/violet connector near the MSD and try the paper clip test. In the off chance it is the connector, it might work. Frankly, I think your box input amplifiers are fried. Somehow you got a high voltage surge that blew them out. Time for new boxes. You can then send these back to MSD for repair. The new style use a single multi-pin connector for all inputs.

[dipso]

I know it's not the connector because I tested it and it has continuity. I'll go check at the box one more time.
I thought about having these repaired but there is a 10- 12 day turnaround time from when they are received. At least that is what it says on the MSD sight.
Any idea what it would cost for repair? I wonder if it is worth it. I'll call them tomorrow.
I was looking at the new 6AL boxes here on Pelican. The wiring looks the same and the mounting looks the same, so it should be an easy swap. Plus they are a little thinner.
But there was one thing I was wondering about them.
Do they have the male spade connector in the end for a tach signal, like the older 6ALs do? That was pretty handy and needed no tach converter.
I do like the little red light for diagnostics on the newer model.

I must of just missed the window, mine are only a few years old. What do you think could of fried both boxes like that? I was driving the hell out of the car with the new jetting and venturis, but it drove all the way home and parked in the garage.
Very strange.
Could my battery charger be the culprit. It has a 2, 6 10 and 50 amp charge. The 50 is for jump starting a dead battery. I did use it at 50, but that was only after I killed the battery trying to start it originally.

[mreid]

Yes, it very well could be. If you ever do that again, disconnect the negative cable before hooking it up.