MSD problems

[bad86]

OK......Very long story short. I have an MSD distributor, coil, tach adapter and 6AL box. All bought new. Each piece was replaced by MSD to eliminate the possibility of a faulty component. Car will run great sometimes for 50 miles, sometimes for 200 miles. It will without warning start to break up, miss and lose power. However it will idle fine. Sometimes if I shut the key off and restart, the car will run fine again for some period. Sometimes not. View attachment 6050

View attachment 6051 If I pull the plug on the 6AL and remove it from the other components, the car will run fine forever. I have had three new boxes from MSD and still the problem persists. I hate to lose the box because the car runs noticeably better with it. I have rerun ground wires.....isolated and insulated all installation wires and still the problem persists. Any ideas???????

Al
bad86

 

[MaximumRisk]

where is the Box located? is it that red box next to the coil? (I can't really tell by looking at the pic)If so the radiant heat from the driver side header might be overheating the box. I would try installing it somewhere else away from direct heat.

 

[bad86]

Thanks, but that's not the box....the box is mounted on the inside of the front bumper support, nice and cool and away from all oter components.

Al

 

[MaximumRisk]

have you tried replacing the ignition module? Most of your symptoms (assuming it is not a fueling problem) are those of a bad distributor (pick-up coil) or ignition module. The weird thing is that if you remove the ignition box the car would run right, so It is a little puzzling I would try the module next and see what happens....

 

[bad86]

Thanks for your input but remember, the car runs perfect with the 6AL disconnected. So it can't be the module or the distributor. And, the car will run great with the 6AL connected.........for a time! It could be 50 miles or it may take 250 mile before it starts screwing up. Don't feel bad......the engineers at MSD are confused also.!

 

[stanginthe11s]

first, where are your power wires connected? what gauge wire was used for all connections? next what coil are you using? where is it located?

 

[bad86]

Power wires are run directly to the battery....coil is MSD as is the distributor. Wire guage is the existing wire on the MSD box. I did not change it

Al

 

[stanginthe11s]

which msd coil are you using and where is it mounted? could your wires be arcing with the msd hooked up? some wires dont handle the extra juice well. all connections are solid to the dist and the coil? any chance of them moving around? the thin red power wire shouldnt be on the batt. it should be on a switch. its odd that it breaks up out of the blue then goes away, that usually points to either a bad or vibrating connection or possible radio interference if its def. the msd box. electronic issues are the hardest online cause we never locate or wire things wrong lol, remember things always happen for a reason so there must be something you or msd are over looking.

 

[bad86]

I had the power to a switched position initially......MSD said that was an absolute no, no and I went directly to the battery. So I do know it screwed up whether it was to a switch or direcrly to the battery.

The coil is an MSD 8227 Blaster. Distributor, coil and box were all bought new at the same time. The coil is mounted on the left shock tower where the factory coil was located.

I have wired and rewired the entire system three times. My mechanic rewired it once.

I have run the car at night in the dark and there is no arching. I have even run the car in the dark when it was screwing up and there was no arching.

The only thing I haven't tampered with, ( this just came to me) is the tach adapter. When I first installed the components, my factory tach did not work. I installed the tach adapter, and it worked. I am going to remove the tach adapter and run the car with the 6AL hooked up and see if it screws up again.

It's a real pain of a problem.......

Thanks for your help......
Al
bad86