msd 20 problems

i have a msd 20 that i bought last year. it worked great for a few runs then hurt the motor this year. i just got the new motor in which also is a aluminum block. went to start the motor and set the timing and let it run. in the process of doing it it stopped firing.i checked all the wires and switch and they are all great. took the wires off the switch and turned it over with the starter which is 24 volt and still no fire so we hooked it back up and was looking at it . i stuck a plug in the wire and layed it on the bell housing where i always do and then it fired a few times. what is up with it ? does the msd box need to be grounded? i have the box screwed to the floor in a sealed box to keep it dry.

 

Yes the box needs grounded . www.msdpromag.com , go to downloads and scroll down until you see the 12 amp generator download , the 20 uses the same diagram . Any other probs call Dave Leahy at 740-362-0251 .

 

the 20 box

this box is tempramental, the first time we used one the car ran for a minute and quit. my ground wire was loose. after doing some calling i ran a ground from the box to each cylinder head, and one to the chassis. that was 150 passes ago. also cover the back of your kill switch with silicone or tape to keep any small metal chips or debris from touching or sticking to the screws and recking your day.

 

i bet that is it after looking at the diagram. it probable was ok at first while everything was clean and new as far as the mounting holes to the floor pan. it will only fire about have the time . ill let you know if it fixes it . thank you again