mleslie951

I posted this thread about a month ago and guess what, I am still having problems. I have the 6AL MSD boxes, msd dist, blaster coil, etc. My problem, is this. Both engines start right up. After warm-up if I shut them down, they will not start again until the boat sits for ahwile. It is electrical, it gets no spark during this time, I have done all of the fuel checks. I have chased down everything I can think of in the MSD boxes, wiring and even just replaced both magnetic pick-ups in each distributor, both were badly rusted. This actually seemed to help, now they both fire right up. One thing I did different this season is replace the battery's. Not standard battery's, but the no label exide type from a friend. Both seem to have excellent charge and no problem turning both motors over so I dont think this is my problem. I noticed, this afternoon while running that both volt meters were running somewhere in the 13-14 range, UNTIL, I clicked the trim switch on the drives, both volt meters dove down to about 6 volts each. Happens when I actuate the trim tabs as well. A large surge of current is dropping the volt meters. Is this somehow draining the system enough to shut dowm my MSD boxes? After warm-up if I idle around the dock at about 600 rpms, it will stop running and will not start back up until it cools down. After that, it will start right up. Anyone else have this same problem? I need help, I have been dealing with this for two months now. Makes for a crappy boating season with the unpredictability (is that a word?) By the way, when one motor would shut down, I would swap the distributor caps, coil wire, even the coils to see if this was the problem, did not help the motor that would die still did nothing until I waited.

Thanks Mike

gsmith9898

I had a similar problem in a street race car. After talking to msd, I did not have enough juice to please the msd system. I changed battery and I never had another problem. It was wierd. The car would start fine but it would fall on its face under load with nitrous.

miamioffshore

If you do end up replacing the batteries, may I suggest the optimum blue tops(i believe blue is the marine version), these things are amazing! Have a pair in my Hummer H1, ran the stereo with engine off for 10 hrs, mind you this is a 10 speaker system with 2 amps and the diesel fired right up like any other day, try that with a normal battery!

mleslie951

I am running two baterry's here, both brand new. It sounds like my problem is in the wiring somewhere, I am thinking a ground wire problem?

Pure Energy

Vapor lock?

mleslie951

Checked that too. It is definately spark related. I can pull the coil wire and nothing? I even switched coils, wires, dist. caps, still nothing. Perfromed all tests MSD recommended. I am thinking ground wire somewhere.....

Vinny P

When it stops running check to make sure you have all power and grounds to the box and distibutor. Use a volt meter, not a test light. You need to have battery voltage at all the power wires. Is the MSD box main power wire hooked up to circuit breaker? It isn't wired to the starter positive stud is it? It should be direct to the battery. Make sure the purple wire, pin #5, in the big plug that goes to the engine, is powered when the key is on ignition.

mleslie951

My MSD box is wired directly into the trim selenoid. Both positive and negeative, had been this way for three years now with no problems. Should I wire both positive and negative directly to the battery on each side, I have twins? Or should I wire the positive MSD wire to the battery and ground the negative somwhere else? Also, I have done the MSD box test. When it is running, I can disconnect the purple/red? wire directly from the msd box going to the distributor. If I pull the coil wire and arc the main MSD box wire (purple/red) I get spark from the coil wire. When the engine dies, I do the same test and nothing? MSD told me that thier could be a low voltage running through the system enough to "trip off" both MSD boxes, that is why the engines will not start up after it has been running. I also received some advise here, run a new negative wire from the helm directly back to the negative side of one of the battery's, then run another wire from the negative post I just attached the helm wire directly to the engine block somewhere to create a ground, anyone try this?

Thanks Mike