How to test a MSD 6AL?
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
How to test a MSD 6AL?
I searched through the posts and didn't find anything really telling me how to test my MSD 6AL (Maybe I'm a bad searcher?).
Anyway, I'm thinking I may have a problem with my 6AL, but don't know a good way to test it, I used the MSD instructions, but all that really did was test my coil, and make sure I wired everything up right (which I knew, as the car has run fine for ~500 miles with it in). Used to start just fine, no troubles, but then one day, it just dosen't start. Cranks fine, gets gas, etc. But, no fire.
What is a good way for a 1 man show to test that I'm getting spark?
Thanks,
David
Anyway, I'm thinking I may have a problem with my 6AL, but don't know a good way to test it, I used the MSD instructions, but all that really did was test my coil, and make sure I wired everything up right (which I knew, as the car has run fine for ~500 miles with it in). Used to start just fine, no troubles, but then one day, it just dosen't start. Cranks fine, gets gas, etc. But, no fire.
What is a good way for a 1 man show to test that I'm getting spark?
Thanks,
David
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: How to test a MSD 6AL? (djlangford)
I went through the same thing you did-- I used the MSD instructions and got the spark as expected from the coil wire, but couldn't get the engine to fire. I went ahead and changed to the Blaster coil (I had planned on putting one on anyway), and repeated the test just to be sure. The difference in the spark jumping to the block was huge!
Next I figured that the problem might have been in my (brand new) MSD billet distributor. I pulled the distributor cap, looked for cracks, checked the pickup to make sure everything looked right, then cleaned the contact at the top of the cap.
Somehow, this sequence worked for me, and I haven't had any problems since.
In terms of checking the spark, I have found that the air cleaner stud fits perfectly into a spark plug boot, and you can hold it near the block and see if it arcs when someone cranks the engine. Now that I've got MSD and a Blaster coil, I don't think I'd try this without some thick insulating gloves, but then again, I've done dumber things. :smash:
Good luck. :cheers:
Next I figured that the problem might have been in my (brand new) MSD billet distributor. I pulled the distributor cap, looked for cracks, checked the pickup to make sure everything looked right, then cleaned the contact at the top of the cap.
Somehow, this sequence worked for me, and I haven't had any problems since.
In terms of checking the spark, I have found that the air cleaner stud fits perfectly into a spark plug boot, and you can hold it near the block and see if it arcs when someone cranks the engine. Now that I've got MSD and a Blaster coil, I don't think I'd try this without some thick insulating gloves, but then again, I've done dumber things. :smash:
Good luck. :cheers:
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Re: How to test a MSD 6AL? (djlangford)
..replace it with a Hi-6? :jester
I think all it needs is a signal, and 12v to make a spark...maybe a speedshop near you could test it, also, have you seen those little MSD displays in stores?? Look on the back of that, may give you an idea.
Good Luck!
I think all it needs is a signal, and 12v to make a spark...maybe a speedshop near you could test it, also, have you seen those little MSD displays in stores?? Look on the back of that, may give you an idea.
Good Luck!
Melting Slicks
Joined: Feb 2004
Posts: 2,435
Likes: 0
From: largo florida
Re: How to test a MSD 6AL? (thebruce)
thebruce, I had the same exact thing happen to me. I bought the 6al, blaster, msd distrib w/ tach drive, and the 8.5 msd wires. Started beautifully all the time. One day a month or 2 after it had to all together i stopped somewhere. Half an hour i get in and it just cranks and cranks. I start messing with wires bumbfoundedly becuase they were all connected well and there was no problem with them. I get in and try cranking it and it started like it used to. Wierd, hasnt done it since though. I wonder what caused it.
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Re: How to test a MSD 6AL? (lostpatrolman)
Ok, I'll fess up... I had this exact same problem with my Crane Hi-6, and it turned out the connection to the coil posts was "less than optimal" I ended up removing the rubber connector and soldering the orange and black wire directly to the coil terminals. The crane box has a light that blinks when it is firing, and when I was diagnosing the problem I saw it wasn't blinking, after fiddling with the coil wires it worked.
With it soldered, it hasn't missed a beat yet...now if only I could manage to keep this darn thing in one piece! (read: cam is back at Comp for analysis)
Good Luck! :cheers:
With it soldered, it hasn't missed a beat yet...now if only I could manage to keep this darn thing in one piece! (read: cam is back at Comp for analysis)
Good Luck! :cheers:
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: How to test a MSD 6AL? (lostpatrolman)
Me too. At least yours was in the garage when it wouldn't start. I was cruising in traffic when it died. It was a hot day, and I was worried the underhood temperature had fried the box, since I guess that it a common problem with MSD boxes.
Don't know if mine was a bad connection on the coil wire or what, but it runs like a champ right now. Of course, that means now I need to "fix" something else until it doesn't! I've definitely noticed a difference in how it idles, and I even think it burns a little cleaner at idle (although I still stink up my garage pretty good due to some untraceable oil burning).
Don't know if mine was a bad connection on the coil wire or what, but it runs like a champ right now. Of course, that means now I need to "fix" something else until it doesn't! I've definitely noticed a difference in how it idles, and I even think it burns a little cleaner at idle (although I still stink up my garage pretty good due to some untraceable oil burning).
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
Re: How to test a MSD 6AL? (djlangford)
Well, I just took it all apart, cleaned it all up, replaced the coil wire, put in a different coil, and same result.
I even had a new (rebuilt) starter (Delco), so I put that in, just in case. Still same thing, crank with no fire.
Should I try a new ign box?
I even had a new (rebuilt) starter (Delco), so I put that in, just in case. Still same thing, crank with no fire.
Should I try a new ign box?
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: How to test a MSD 6AL? (djlangford)
If you have a "ready to run" distributor (one that works without the MSD box), just disconnect the box and wire the coil to the distributor as you would without MSD. If it starts, then the problem is definitely the box.
If you've already tried the diagnostic sequence in the MSD manual and can't get spark to the block, then it's definitely the box. If you're getting a spark when you do the test, but no fire, then you should check spark at the plug end of the wires. If there's no spark at the plugs, then the next place you need to look is your distributor.
I feel your pain. :banghead:
Good luck. :flag
If you've already tried the diagnostic sequence in the MSD manual and can't get spark to the block, then it's definitely the box. If you're getting a spark when you do the test, but no fire, then you should check spark at the plug end of the wires. If there's no spark at the plugs, then the next place you need to look is your distributor.
I feel your pain. :banghead:
Good luck. :flag
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Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Re: How to test a MSD 6AL? (djlangford)
I had a 6AL problem a few months ago, here is what MSD instructed me to do....
remove the coil wire from the distributor, and put a plug in, and ground it. Next, pull the wire going from the 6AL to the distrubutor off, (should be violet and green i think). Next, make yourself up a little jumper, and put it across the two wires coming from the box, the green/violet. Turn the key on, then you pull that jumper off, the plug should spark. Do it a few times, you should get a consistent spark ONLY when the jumper is pulled off. Mine was sporatic, and didnt give a nice spark each time i pulled it off, somethimes it sparked when i put the jumper in.... this is bad, I ended up having two shorted diodes within the box, but MSD fixed it up for me no charge.
Hope this helps
Joe
remove the coil wire from the distributor, and put a plug in, and ground it. Next, pull the wire going from the 6AL to the distrubutor off, (should be violet and green i think). Next, make yourself up a little jumper, and put it across the two wires coming from the box, the green/violet. Turn the key on, then you pull that jumper off, the plug should spark. Do it a few times, you should get a consistent spark ONLY when the jumper is pulled off. Mine was sporatic, and didnt give a nice spark each time i pulled it off, somethimes it sparked when i put the jumper in.... this is bad, I ended up having two shorted diodes within the box, but MSD fixed it up for me no charge.
Hope this helps
Joe
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
Re: How to test a MSD 6AL? (djlangford)
Well, with a little help from Cardo0, we discovered that, though there is power on the switched lead (only when key ON), and power at the battery connection, there is no power on the + lead of the coil with the key ON or at crank.
He's got a 6A we'll try putting that in tonight and see how it goes.
I should get +12v at the coil +, right?
David
He's got a 6A we'll try putting that in tonight and see how it goes.
I should get +12v at the coil +, right?
David
Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: How to test a MSD 6AL? (djlangford)
NOPE, msd's fire around 400 volts TO the coil, then thousands of volts out of the coil. With an analog meter you will get no volts before the engine is cranked and running. Once running I got around 4 volts at the coil, but you actually have way more than 4 volts. A digital meter showed nothing at all.
