Msd 7?

Rich Biebel · 10-22-2010, 05:57 PM

I had an MSD 7al 2 in my Firebird Stocker. One day at the track I started to get misfiring over about 6000rpm and the tach was jumping around when it misfired. This engine had a crank trigger and most everything but the MSD box was new. I borrowed my friends identical 7al2 and the car ran perfect...no missing. I sent my box to MSD.....they said they could find nothing wrong with my box. I swapped it back into my car one day at the track....same problem returned...missed badly over 6000 and tach was shutting off when it missed....removed it and reinstalled my friends box same day....no missing. I bought a Digital 6 and matching coil and installed that. That box failed for the person who bought that car and it was no more than 2 years old when it failed. Probably got wet sitting out in the rain from waht I was told....I used to think MSD was the best ignition and boxes either worked or they didn't. I bought an MSD ignition box tester that they sell.......it allows you to fire the box without the engine running......pretty handy for testing a lot of things that are rpm triggered and to see the spark energy at any rpm. If I have a box I am not sure about...I'd replace it and MSD is not the only brand out there...Mallory has a good reputation for reliability.....

If you have an MSD distributer with mag pickup in the distributer your problem could be the small module in the distributer........I have a friend who chased a miss for months and that is what his problem truned out to be.....

rod · 10-22-2010, 07:43 PM

1. i was unaware that there were different boxes for different cylinders. will check that.
2. this chevy has a mallory uniliite for trigger.
3. the tach needle does, in fact, moooove towards 0 when it pops.
4 i have raced this car/engine for 37 years and never had it pop at the top of a gear. it does have an 8K top rpm chip, so it shouldn't be that as 7K is as high as i ever push it.
5. i have 2 different coils i can sub in. will try that also.
6.i am so MAD i could scream !!!!!!!!!!!!!!!!!!!!!!!

guys thanks for all the suggestions
rod in AZ

10-22-2010, 05:57 PM	#1
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: Msd 7? I had an MSD 7al 2 in my Firebird Stocker. One day at the track I started to get misfiring over about 6000rpm and the tach was jumping around when it misfired. This engine had a crank trigger and most everything but the MSD box was new. I borrowed my friends identical 7al2 and the car ran perfect...no missing. I sent my box to MSD.....they said they could find nothing wrong with my box. I swapped it back into my car one day at the track....same problem returned...missed badly over 6000 and tach was shutting off when it missed....removed it and reinstalled my friends box same day....no missing. I bought a Digital 6 and matching coil and installed that. That box failed for the person who bought that car and it was no more than 2 years old when it failed. Probably got wet sitting out in the rain from waht I was told....I used to think MSD was the best ignition and boxes either worked or they didn't. I bought an MSD ignition box tester that they sell.......it allows you to fire the box without the engine running......pretty handy for testing a lot of things that are rpm triggered and to see the spark energy at any rpm. If I have a box I am not sure about...I'd replace it and MSD is not the only brand out there...Mallory has a good reputation for reliability..... If you have an MSD distributer with mag pickup in the distributer your problem could be the small module in the distributer........I have a friend who chased a miss for months and that is what his problem truned out to be..... __________________ Rich Biebel S/C 1479 Stock 147R Last edited by Rich Biebel; 10-22-2010 at 06:02 PM.

10-22-2010, 07:43 PM	#2
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 315 Likes: 0 Liked 20 Times in 15 Posts	Re: Msd 7? 1. i was unaware that there were different boxes for different cylinders. will check that. 2. this chevy has a mallory uniliite for trigger. 3. the tach needle does, in fact, moooove towards 0 when it pops. 4 i have raced this car/engine for 37 years and never had it pop at the top of a gear. it does have an 8K top rpm chip, so it shouldn't be that as 7K is as high as i ever push it. 5. i have 2 different coils i can sub in. will try that also. 6.i am so MAD i could scream !!!!!!!!!!!!!!!!!!!!!!! guys thanks for all the suggestions rod in AZ

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