Is it another dead MSD box?

[Paul_G]

I put the 383 in my 69 Roadrunner until the Hemi is rebuilt. The 383 ran great when pulled out of the Charger. The Roadrunner ran great (no ignition issues) when the Hemi was pulled out, other than the Hemi needing a rebuild.

Doing the start up yesterday on the 383, the engine idles okay. When the throttle is opened the engine repeatedly backfires through the exhaust. Sounds like spark scatter. Check the plug wires, all in the right spots, checked under the cap, worn but no visual damage. Moved the base timing around from 0° to 20°, engine idled OK, backfiring on throttle opening continued. Put it back to 15°.

I tried this; connected the vacuum advance to manifold vacuum, as the advance came in and started to raise the RPM the engine started to backfire through the exhaust. Hmm?

It has an older MSD 6AL box, blaster 2 coil. Holley 670. And a tired stock electronic distributor.

First I swapped the Holley for an Edelbrock 600 I have. Still backfiring through the exhaust.

Then I swapped the distributor for a brand new one I bought from Mancini that was going on this engine anyway. Still backfiring through exhaust.

My next idea is to temporarily swap in a stock electronic ignition system to eliminate the MSD box.

Any other ideas welcome.

 

[4speed68rt]

Make sure that you have good fresh, high octane gas.

 

[rumblefish360]

I’ve personally have had the worst luck of anyone in crappy MSD boxes with only 1 that has worked consistently over the years and 4 or 5 other boxes failing sometimes within days. I’ve sent all the boxes back that failed with ether new ones replacing the broken one only to fail or the box was repair only to fail.

Besides the one and only box that worked for 20 years perfectly, I haven’t had a box last a summer. I haven’t had a repaired or replaced box last more than a few weeks at best.

MSD called me up and was wondering and we had a conversation on the matter. I explained to them exactly what I was doing and the order of doing such installations.

I am no dummy. Being in the hobby and in the biz of working on old cars and other mechanic trade work for a career over the last (at the time, 20 years) 33 years in total before retiring, there is t much I can not do. While electrical is not my favorite, reading wiring diagrams or even rewiring and designing my own system is within my grasp.

In the end, I said to there tech “I don’t know how you guys stay in biz with a track record like I’m having.”

I do highly recommend a multi spark ignition mostly for the cruiser cars.

I suggest going through your entire system from lead power wire to ground wire making sure the connections are as good as they can be. Double check any splice. I suggest an epoxy coil as they can be mounted in any direction and never leak oil. Clear every wire and make sure they’re not broken and away from any source that may cause an issue like a sharp corner or bracket and tied together away from other wires.
Open your plug gaps until the engine runs rough. Try a .050 gap.

(On the race track, I have not seen a difference in performance against a Chrysler Chrome box and a high energy coil.)

 

[Cheapsunglasses]

MSD= May Suddenly Die

 

[rumblefish360]

That has been around ever since I can remember.

 

[Cheapsunglasses]

I know

 

[6PKRTSE]

We use literally hundreds of MSD boxes a year and yes occasionally there is a faulty box or distributor once in awhile. We send them back for a rebuild and mysteriously they always run their checks/tests and find nothing wrong and send them back and now they work. (they don't like to admit anything is wrong and repair them at no charge and try not to get a bad name out there for defective products).

 

[toolmanmike]

MSD= May Suddenly Die

There's a reason why every race car trailer has at least 2 spares in it.

 

[rumblefish360]

Excellent to read that. I wish I had that track record with them.

As I said to the OP, just double check everything.

 

[pnora]

I put the 383 in my 69 Roadrunner until the Hemi is rebuilt. The 383 ran great when pulled out of the Charger. The Roadrunner ran great (no ignition issues) when the Hemi was pulled out, other than the Hemi needing a rebuild.

Doing the start up yesterday on the 383, the engine idles okay. When the throttle is opened the engine repeatedly backfires through the exhaust. Sounds like spark scatter. Check the plug wires, all in the right spots, checked under the cap, worn but no visual damage. Moved the base timing around from 0° to 20°, engine idled OK, backfiring on throttle opening continued. Put it back to 15°.

I tried this; connected the vacuum advance to manifold vacuum, as the advance came in and started to raise the RPM the engine started to backfire through the exhaust. Hmm?

It has an older MSD 6AL box, blaster 2 coil. Holley 670. And a tired stock electronic distributor.

First I swapped the Holley for an Edelbrock 600 I have. Still backfiring through the exhaust.

Then I swapped the distributor for a brand new one I bought from Mancini that was going on this engine anyway. Still backfiring through exhaust.

My next idea is to temporarily swap in a stock electronic ignition system to eliminate the MSD box.

Any other ideas welcome.

Did you try another coil? Do you have a spark tester to see what the coil can put out?

 

[icetech]

Just curious, does anyone make boxes like MSD(other than msd..) anymore? I saw mallory has something but didn't come up with much else..

 

[Cheapsunglasses]

Mallory is rebranded msd. Holley owns both companies

 

[icetech]

Mallory is rebranded msd. Holley owns both companies

Ahh... well pewp

 

[91r/t]

MSD boxes become junk now adays, Chrysler boxes are discontinued and the ones before that sucked from China, and there's little to substitute them with.......I see a trend here not in our favor haha!

 

[icetech]

MSD boxes become junk now adays, Chrysler boxes are discontinued and the ones before that sucked from China, and there's little to substitute them with.......I see a trend here not in our favor haha!

MSD boxes aren't junk today.. they have always been.. i had to go save friends so much in the middle of then night due to dead MSD parts.. "Might Suddenly Die" isn't a new thing
I saw Mancini selling orange boxes (stock type) are they also bad quality? i'm going to have to switch my car to electronic ignition and figured i would just do a stock type setup.

 

[91r/t]

I have been eye'ing original tested boxes from the early 90's and back and they have the most luck. Not sure on the summit, jegs, mancini, napa replacements. They all lead me to believe they are all junk with crappy vendors probably makin them all in the same building. I am running a MP chrome box from the 80's on my runner and a rev-n-nator on my charger but I have emailed them a bunch wanting to warranty a coil that failed and I have np response from them. Their website shows no stock so I am unsure if they are even in business anymore. Not many options anymore.

 

[icetech]

I have been eye'ing original tested boxes from the early 90's and back and they have the most luck. Not sure on the summit, jegs, mancini, napa replacements. They all lead me to believe they are all junk with crappy vendors probably makin them all in the same building. I am running a MP chrome box from the 80's on my runner and a rev-n-nator on my charger but I have emailed them a bunch wanting to warranty a coil that failed and I have np response from them. Their website shows no stock so I am unsure if they are even in business anymore. Not many options anymore.

I'll be doing as i always have... carry a toolbox with spare ignition parts Nothing worse than a 1 man car show on the side of the road

 

[Cheapsunglasses]

Always keep a trusty points dizzy in the trunk

 

[91r/t]

My neighbor was amazed the one day I called him broke on the side of the road from my house. I said I need a ride home and back to the car with a couple parts and tools. He asked me did I really think I could get it running I said watch this......pulled the spark ecu box and threw another on and waaaalaaahhh we drove home. He was amazed but I told him dude there's like 3 or 4 ignition parts that make this car tick and give it life hahahaha! I was a bit late to the carshow but I made it dammit!

 

[GTX JOHN]

I only have good luck with the old Analog MSD stuff from 25/35 years ago qnd
that is what we strictly run in our race cars. So do most of the guys I run
against in Superstock and Stock. Fortunately, I have an extra dozen still new
in the box from back then we MSD helped up. I just do not every have an issue with them and
some have been in my cars since early 90's. However, my wiring is always
up to snuff and examined regularly.