Hi there,

I'm looking to install a new distributor/coil system in my mid-80's 351W. I'm looking at MSD's line, and have some questions. Currently, the truck has an old electronic ignition module separate from the distributor, and the tach is wired to the ignition module. All these new distributors I'm looking at have the ignition modules built in, but have "optional" wiring for using an external module if desired.

My questions are:
- what would be the benefit (if any) of purchasing an new external ignition module and using it, instead of just using the one build into the distributor?

- if I didn't get an external one, how would I wire my tach, now that there is no module to wire it to?

 

I hate to suppress someone buying stuff and helping the economy, but the "old" ignition system you have now is going to be hard to beat. The only drawback to it is messing with the timing curve, since the weights and springs are down inside the dist, but most people don't know what they are doing when trying to re-curve a dist anyway.

If you want to buy the MSD box, you can use the original Ford dist to drive it.

 

I know, those old ones were pretty solid devices. The thing is, it just doesn't do the job anymore. The vacuum advance is gone, the gears are worn, the cap is cracked (the billet might be too...). It's at the point where repairing or rebuilding probably won't be worth it. It's at the replacement stage.

So, my questions still stand.

 

I agree with what Franklin said. Very good advice.

YES, they are pretty solid. So why do you want to try something "aftermarket" that may NOT be pretty solid?

If it is not doing the job anymore, its time to rebuild it, just as you would your engine or transmission. The vacuum advance is part of your distributor. All you have to do is use your old distributor as a core on a new one, and then maybe buy another coil, if yours is bad. Buy another cap/rotor (these are wear items), and then I would strongly suggest replacing your plug wires and spark plugs too while you are at it. This shouldn't cost you near as much as the MSD, and you already know it is solid.

Unless you are drag racing your truck and spending a lot of time above 5000 RPMs, you do not need the MSD ignition or any other "aftermarket" ignition system. Also, consider this: with the stock Duraspark system, if ANY part of it fails, you can walk into ANY auto parts store in ANY town and they will have replacement parts. With MSD, you will probably have to order the item, which means you will have to sit and wait.

 

Ok, fair enough. One of the other reasons I was even looking into it is because the external ignition module is pooched (looks like it had some severe water damage or something; this engine hasn't been run in quite a while, it's not like it was working fine and just had a whim to replace working parts). From what I can find, replacing the ignition module is about the same price as getting a new distributor with the module built in. That's why I was looking into it.

So what's my best option in this case?

 

OK then. If you go with the MSD, what happens when the "built in" coil or the distributor goes bad?

That's right. You will have to replace the ENTIRE assembly and then sit and wait for it to come in. That would rule out any price savings you might get by not going back with a working stock system.

Even if you can buy parts for it, I will say it again: you will NEVER see the benefits of an MSD unless you go over about 5000 RPMs. In fact, the stock system you have now will out-perform the MSD or any other aftermarket ignition system out there.

 

Ok, you've made your point. Several times in fact. But it still doesn't help me. What should I do to fix the CURRENT problem (bad ignition module)? Just replace it with the same thing?

 

YES.

If your current problem is a bad ignition module (how do you know it is bad?) go to a local junkyard in your area and get a MOTORCRAFT ignition module like the one you have on your truck now. There are tons of good ones still out there is wrecking yards for about $10.

 

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