Hey guys, Ive got a 1977 f150 4x4, 400, 4 spd and its had a MSD box since I got it. I cant seem to get the thing to run correctly at all. It back fires and coughs when entering high RPMs in high gears. I thought it was carb related, changed to a different carb, no change, replaced spark plugs, improved engine idle but still issues in 3rd and 4th, changed the springs in the Distributer, no change, checked timing, advanced a little no change, retard a little no improvement. I'm wondering if the MSD box is going out on me or maybe the Distributer is bad. I was going to return it to stock ingnition setup and check, cant afford to purchase a new MSD @ 265.00 just to test it out, to see if that improves. got a friend who has a junkyard and he has a couple of dents in the yard with most of the ignition setup intact so long as I return the stuff I use he wont charge me. What do you think could be the problem? if I return to stock what all do I need. This thing is kind of mickey mouse on the wiring so assume nothing from stock ignition is left. lol

 

Hi mate, check your coil by swapping out with a known good one. Sounds like your spark is breaking up under high load, classic sign of a coil going bad.

Another way to ensure a better burn is to give your plugs a bigger gap - I've gapped mine to about .060" to ensure that there is higher energy being produced by the coil and better ignition.

The coil alone is worth it just to check if you haven't already.

Cheers - boingk

 

A pic of your setup under the hood might help too Justice.
Is the MSD box being used without a Duraspark module? Is the distributor still a Duraspark, or could it have been changed too?

Since wiring is the key to having any of this stuff be a success (and may even be the cause of your trouble to begin with!) seeing what you have might help.

Good luck.

Paul

 

well guys just thought id update this thread. After toying with the idea of going back to stofck and getting prices of everything I was gonna need I decided to ditch the msd and coil and go with an HEI distributor. during the break down of the current system also discovered that a couple of the plug wires were damaged. but being that they had a clamp holding them onto the distributor cap I never thought to check them. However I installed the new dizzy and a new set of wires and after some dialing in I can say this truck has never ran this well. It pulls and will fly down the road. still running the edlebrock carb that I borrowed from a friend. going to drive it for a bit to get a baseline and then reinstall the holly to see how we go from there. other than the squaling from the alternator belt on my 3G install I'm pretty happy. Hoping ive sourced out most of the gremlins that have been plagueing me for the majority of the time ive owned this truck.

 

Thanks for the update!

Good to hear she is running well, always helps when the distributor and leads are doing their job.

I'm a fan of the HEI system, too, very easy to manage and works a treat.

- boingk

 

I have a 79 F150 that I just did 460 conversion on I need to do something with the ignition box it has the factory DURASPARK distributor but everything else is gone. I can’t decide what to do I was thinking HEI as well

 

I'm a big fan of the stock Duraspark setups. But you can't argue with the fact that the HEI is simplicity itself.
What you can argue however is, you either get what you pay for or you takes your chances.
I have not heard the number of complaints here that I have over on other forums over the years, but almost since the import companies started cloning the HEI conversions for Fords there have been complaints. The original DUI (Davis Unified Ignition) versions were super reliable, super slick and super expensive. Hence the quick rise of the cheapy imports.
That said, the chance you'll get a good one is actually pretty good still. Just the chances of you getting a $100 paper weight are better than average.

In our trucks they actually make sense since the hood clearance is not an issue. They put out good spark, are easy to find replacement modules for (always use thermal transfer paste when replacing one!) and also inexpensive, and most of all are easy to wire up.

The Duraspark is the opposite of easy to wire if you're not comfortable with that kind of stuff. But it has some great design characteristics that make it a good setup as well.
Since you already have the distributor, you'd theoretically only need a module. Is ALL the rest of the wiring gone too? Or do you think there are some empty ignition wiring components still tucked in some corners somewhere?
If so, all you need is the module itself. Not near as expensive as a new (even a cheap one) HEI setup.

Got pics of any unused connectors?

Good luck either way. I'm not brand-centric, but I do like to keep things within the same family when the same brand parts are good. No problem swapping out Ford crap for GM goodness any more than I have swapping out GM junk for Ford sweetness.
But if it works and gets you down the road with a smile, it's worth it.

Paul

 

I got mine off of summit. So far its worked well. I don't have many miles on it yet. but the cost for a new cap or module sure beat buying a new msd box.