Msd problems

have a 6al digital box / coil / distributor all MSD. engine will not fire and put in back up HEI and no problems with same wires. we have spark at the coil wire at cap. spark at plugs at random. new cap/rotor and pick up. pluged new running box from other car into ours and same thing. called MSD but that was a joke. have never came across this in my 30 years of racing. check all power and grounds can't find any broken wires. good whit/blue spark out of coil. rotor to cap contact is fine. any one ever ran into this problems or have any idea what to check next. running on HEI right now but really need my msd back \. thans for any help.

The only thing i can think of is the cap to rotor button connection must not be very good. To conform you could rotate the engine to line up the rotor with any tower and pull that plug wire. Unplug the connecter to dizzy and short the wires with a paper clip or something. If you get a spark everytime you break the connection then repeat for every tower to find the problem. You could also put a timing light on any plug wires and crank. Everytime that plug fired the light should flash. You might also want to check the up/down play in the dizzy. Spec is .005

If the engine was running at one time with the complete MSD setup then I would put a new magnetic pickup in the distributor.

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Originally Posted by mod71m

If the engine was running at one time with the complete MSD setup then I would put a new magnetic pickup in the distributor.

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The OP said he did that already. My test above will eliminate that as a possibility without buying and throwing parts at it which gets expensive real quick. The OP could also pull the dizzy and spin it either by hand or with a drill and watch the plugs as well. It also gives him a chance to inspect the gear and pin.

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Originally Posted by Lizardracing

The OP said he did that already. My test above will eliminate that as a possibility without buying and throwing parts at it which gets expensive real quick. The OP could also pull the dizzy and spin it either by hand or with a drill and watch the plugs as well. It also gives him a chance to inspect the gear and pin.

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check it, it is ok going to change the coil. the only thing we can think of is it just is not strong enough to go though the cap. good spark at the end of the coil wire with a spark plug in the coil wire. will post what we find.

was a bad coil. old onr had a nice white/blue spark but would not run the engine go figure.thanks for the help

had issues like that before, the wiring from the box to the dist plug in was shorting out ,replaced it and problem was solved.

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Originally Posted by bob75

had issues like that before, the wiring from the box to the dist plug in was shorting out ,replaced it and problem was solved.

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You can check the coil by doing a resistance (ohms) across the primary and secondary side of the coil. Coil + to coil wire outlet and Coil - to coil wire outlet should have around 750 ohms resistance.

Hey guys, Find someone that has the MSD Tester for the 6AL boxes. You DO NOT unhook any thing. you unplug the two wire connector (black and purple) wires at the distributor and they plug into the tester. Once you do that you hook up to the coil wire at the distributor cap. The tester will then run the RPM up to what ever you have the chip or dial set at. The only thing you do not test is the distributor and you can line the distributor up with a cylinder and check spark to the plug also.....Call MSD and talk to them they will help you, If not call the Tech Line at Jegs.....those guys are pretty good. Wish I was closer I would bring my tester and try to help.