MillenniumFalcon

Reviving an old thread here to see what gap people are running with an MSD box... from what I can tell, opening up the gap to the wide MSD recommended clearance is not a good idea..

Right now I'm at .032, and I'm wondering whether I should just re-gap to stock spec's.... I'm sorting out CIS issues and getting ready to tune the c/o, and I want my ignition to be squared away prior to working with the CIS.

Help is appreciated.

Steve Weiner-Rennsport Systems

Dave,

There are a lot of opinions out there about this so I'll simply offer mine.

MSD's are terrific ignitions, however you'll not get any of the benefits if you maintain the stock plug gaps. Open them up to .040-.045 and you get better idle quality, as well as little more performance.

The Caveat here is that everything must be in top shape to handle the additional current and this means plugs, wires, connectors, cap & rotor must all be perfect. I usually replace the rotor with one without the suppression resistor.

Hope this helps,

MillenniumFalcon

Thanks, Steve.

Everything in the ignition system is new. As far as the rotor goes, I have a rev limiting rotor in there right now. I'm not sure whether this is what you mean by a "suppression resistor" rotor?

Steve Weiner-Rennsport Systems

Those rotors contain a suppression resistor that should be removed and replaced with a piece of 8g copper wire or a small bar of copper and soldered in place.

MillenniumFalcon

Okay, first I have heard of that- sounds like a nice afternoon project. Thank you.

Reiver

Steve,
Is there a compatible rotor that does not need a fix? I believe I've read about using a VW rotor I think.

theiceman

This guy just can't be for real
Must be a spammer trying to sell video cards or something

Reiver

I think that's the guy from Nigeria holding 25 million from one of my long lost relatives....he just needs my bank acct # for the transfer...at least he writes like him.

whalebird

If you go to lowes big box home store and look in the lawn mower parts isle you'll find Bosch wr7dc boxed individually for some kind of mower they sale. Easy to find in a pinch

MillenniumFalcon

The plugs I found at Lowes are the WR7DC+ which are copper and Ytrium.

From the troubles that I am having with my MSD system ever since I opened up the spark plug gaps to .032 [edit], I'm guessing that if you decide not to remove the suppression resistor from the rotor, that you may/will run into trouble with gaps any larger than the factory spec .028. My car is barely idling now and doesn't want to start cold anymore with a wider gap and the stock rotor... I had installed NGK BP7ES plugs gapped at .032

c/o readings were all over the map with cylinders misfiring and dumping raw fuel into the exhaust.

Changing out the NGK BP7ES plugs tomorrow to warmer plug WR7DC+ with a stock .028 gap until I have the time to modify the rotor.

Amber Gramps

I hate Lowe's with a passion, but I'll take one for the team. It's been 4-1/2 years since I started this thread and 4-1/2 years since I changed my plugs. .....sooooo it's about time I changed my plugs again.

MillenniumFalcon

I thought this might be of some interest:

These plugs pictured below have about 20 minutes of run time on them. I pulled them out after I could not get my CIS mixture adjusted with an LM-2. I had extremely poor cold starting and a horrible idle, due to raw fuel being dumped out my exhaust, making it impossible to tune...

When I pulled my CIS system out for inspection and replacement of injectors and rubber sleeves, I decided to also change the spark plugs as well, and my son had helped me gap and put them in.

After everything was back together, when I finally managed to get the engine started and running long enough to warm it up, it ran so badly that I thought it had to be a problem with the CIS, so I ran every pressure test in the book on my system, and everything performed flawlessly. I had also installed a rebuilt vacuum WUR, and that was right on spec.

So I turned my attention back to the ignition system...

I pulled the plugs back out, grabbed my feeler gauges (not my spark plug gapping tool) and found one gapped at .028, one at .029, and the rest at .032-.033.

In the picture below, the plug gapped at .028 is the 2nd one from the top. The one on the top is the plug gapped at .029. The other two are .032, and they are completely covered in soot.

As mentioned in an earlier post, I had installed all new ignition components and an MSD box a few months ago after I bought the car, because my CDI had fried on the freeway after the coil wire pulled halfway out, frying both the coil and the Permtune box. At that time, I also installed an RPM limiting rotor with the suppressor resistor in it when I changed out the ignition components. But I did not change the spark plugs. Everything ran fine. During the CIS overhaul, I installed new spark plugs they obviously went in with varied gaps (but that's another story).

Anyway, it is interesting to note that with the plugs opened up to only .032- .033, and the resistor rotor in the cap, the MSD would not consistently fire the plugs, making starting and idle almost impossible.

I installed some new Bosch plugs this morning, gapped at .028, and my engine fired up on the first turn and idled smoothly.... and it was cold as a witch's tit.

I assume that it is the resistor rotor that is not allowing the spark energy to jump a .032 gap.... I never would have guessed that this would limit the gap that you could run.

Somewhere down the road I'll solder in a copper strip in my rotor and open the plug gaps up and see what happens. For now, I am just happy to have it running smoothly again.

infoleather

Platinum plug itself there is nothing wrong, it just seems that everyone's experience of the "real world" over the years. Male motorcycle riders or bikers must make sure that they measure their Designer Black Leather Jackets For Men in cwmalls.com carefully so that they order and buy the right size of this Men's Black Leather Motorcycle Jacket to fit them without any problems.

Amber Gramps

Twice in my life I fell for the platinum plug BS. Once on my chevy, and once on my honda. Both times the platinum plugs were back out in just a couple weeks. Total crap on older engines.