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Discussion Starter · #1 · (Edited)
Had to winch the bomb on the trailer Saturday. Ran great, shut it off and it would not restart. No spark.

6AL2 MSD box, regular stock style MSD coil.

I suck at trouble shooting. Never learned how to run an olm meter thing. So I just use a test light .

Symptoms: MSD Box flickers when turned on and light pulses with every signal when engine is turned over as it receives a signal from the distributor.

If I check the positive on the coil it too pulses as the engine turns over.

I changed out the box no spark.

Changed out the coil, still no spark. The backup coil looked really bad. It was a stock coil that I kinda suspect not working anyway.


Could it still be the coil? Since the MSD is sending a pulse signal as the engine turns over it must be working ok?


Any help would be great!!

Thanks,

Jeffro
 

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Discussion Starter · #3 ·
Thanks Rich!,

Gremlins, I hate gremlins. Checked at the coil, had spark. Checked at the cap, had spark, checked at the plug had spark. Then it started!

Taking the power washer to it while it's running to see if I can get it to duplicate the sparklessness!


Thanks,

Jeffro
 

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You might want to check out the pickup coil in the dist I have went threw several of them in mine! Good Luck I Hate Gremlins Too!

Derrick
 

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The positive side should have constant power, the negative side is the one that pulses as the engine turns over. The pickup assembly acts as a set of points to break the current and soak the coil.
 

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Discussion Starter · #6 ·
H--MMM,

I better check again Critter. Sounds like something isn't right as the positive I'm almost sure was pulsating!

Thanks,

Jeffro
 

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The following test will determine if your MSD is producing a spark.



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:
1.Inspect all of the wiring.
2.Substitute another coil and test again. If there is now spark, the coil is at fault.
3.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.

4.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:
1.Inspect all of the wiring.
2.Substitute another coil and test again. If there is now spark, the coil is at fault.
3.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.
4.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.



No 12v present at Coil +
1.One common question in regards to MSD Ignition controls is “Why isn’t 12V power on the orange (COIL +) wire?”
The main reason 12V won’t be present at coil + is because your MSD ignition is a Capacitive Discharge Ignition. Like all CD ignitions they use a large capacitor to discharge 420-480 Volts to coil + and coil – will normally be connected to ground. (That’s why you wont see +12V on coil +)

2.Most all stock ignitions are Inductive Ignitions, these will normally be connected to the + 12V ignition switch to coil + and coil – is connected to Points or the Factory Electronic Module. (That’s why you’ll see +12V on coil +)
 

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If your still having issues and you have a msd billit distributor, you may want to check the magnetic pick up. I had two go bad in the past couple years. All of a sudden it wouldn't start but once in a while it would when we kept on trying. MSD's website has a procedure for testing the pickup. I know quite a few people that have had them go bad.
 

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Here's one I ran into this last week. Was running ShaZam on the trailer to get the oil back up into the can after sitting on the trailer for 2 weeks. Was holding the r's at 2000 when the needle all of a sudden just went to 0 the back to 2000 then it started to do this flicker thing about 6 times then it just quit. So went threw to check for spark. pulled the + and - coil wire off and put back on then pulled coil main plug wire and replaced it. hit the switch and ShaZam fired right up. Thought it must have just been a loose wire but then it did it again and shut off. So now I figure it might be the coil pick up in the dizzy. so pulled the cap off and everything looked good in side there. But just as I was going to put the cap back on I notice the rotor was all black in the spring clip dilly boob. flipped the cap over and the little piece of carbon that the rotor rides on was not there it was ate away into the cap. threw a new cap on and cleaned the rotor up and all is good again in the engine compartment.



Dan
 

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hey jeff you dont have the coil wires and the dizzy pick up wires running next to eachother do you?? like dad said thats what we fought all night friday night and it was the magnetic pickup in the dizzy. but i know you get radio interference i think is what they call it if you put those wires next to each other they will jump just like putting # 7 and #8 spark plug wires together

Dexter
 

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Discussion Starter · #12 ·
Thanks everyone for the help. Marshal thanks for all the instructions. I printed them off.

Since it's running, it's a little hard to put your finger on anything!

Dan, I have heard a similar story before and remembered it. I checked that area out earlier when it wouldn't start and it was fine, but I was sure hoping that it was up in the cap area.

Nitemare & David, I'm leaning toward your suggestions. It's just a hit and miss thing. I took it to the car wash, started it and put full force everywhere top of the cap bottom, all wires and didn't miss a lick!!

Dex thank for the suggestion but we have run the same set up all year. Our signal and coil wires do run together and I'm sure could cause problems but if they have been ran in 15 races and had no issues I would think they would continue to be ok. But if I rewire it I will separate them for sure, thanks!!

CRITTER I CHECKED MY POSITIVE ON THE COIL AGAIN AND IT IS THE ONLY ONE THAT PULSES MY LIGHT? It starts and runs so I'm scared to change anything??:confused:


Thanks again everyone!

jEFFRO
 

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Jeff - I had that exact same problem a while back. 1st time, I had to stick a screwdriver in the coil and tap the coil wire on the screw driver till it sparked, pulled out the driver, plugged in the coil wire and it started. I switched to a MSD HVC2 coil, no more problems. The other time was with a MSD offroad ignition box, it just plain ol s**t the bed and quit working, switched to MSD 6 Plus, no more issues. To me it sounds like a bad coil, and it is one of the cheaper parts to replace, I'd start there I guess. How old is the box?
 

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Discussion Starter · #14 ·
Myron,

6al box is only a year. Coil is 5. it starts and runs great now but..... Think I will pick up a coil like you suggest. I run an MSD dist but have the stock ford with a cast gear?? I keep for a backup. I'd hate to put that in but in a pinch I guess I would.

Thanks Myron,


Jeffro
 

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Need to trace your wiring, sounds like you may have the coil wired backwards which will cause it to overheat. Positive side of coil is ignition power from switch, negative comes from pick-up in dizzy.
 

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Discussion Starter · #16 ·
Critter thanks!

Just want to make sure before I tear it apart. I'm running a manual dial msd retard box for stating purposes. A 6al2 box and a stock style msd coil.

I'm only using a check light to test for voltage.

The negative always shows nothing. The positive shows nothing when the key is switched on but when the engine starts turning over and the dist sends the signal to the box it in turn sends the signal to the positive on the coil.

My light may not be sensitive enough to pick up what it needs but I would think I need a constant 12v to that coil unless the 6al2 does something different? It's a totally new digital box that has an external light and built in rev limiters, and a two step. But I would think the coil should work the same no matter what.


So run my ignition switch right to the positive on my coil then take that pulsating wire on the positive side and switch it to the negative side? That should do it right??

If this is so, it there any way this could be limiting me on my rpm's? This thing used to zing to 8+ and all summer it see's only 74 at the most. I had a wiring problem last year and tore everything apart. Must have hooked up something wrong then??


Thanks again for all the help!!


Jeffro
 

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Like I said before Jeff, the positive is switched power from the MSD, (constant voltage), the negative comes from the dizzy, (the pick-up causing the "pulse"), and yes, it does have a tendency to limit RPM. You may have ruined the coil!
 
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