Spark Problem
 

My 84 GSL normally idles at 1000 rpm (I set it high for those times when it's just a hair hot for the choke, but not quite totally warm where it doesn't run quite so well). I'm experiencing an issue where the idle will suddenly change (random with no movement, extra throttle, etc.) down to 600 rpm and the car will almost stall.

Even driving at 3000 RPM, it will suddenly go from normal to "messed up" and lunge, lurch, etc. and generally be under powered.

I have since determined that one entire coil is dead so 2 plugs are not firing when it "cuts out." I have a few parts cars (long story) and so I robbed the coils from one of them, and I know they work. The coil is still dead, but remember that it can cut back in. I also changed the wire, to no avail. Oh, before the coil I also put in a new cap and rotor because mine looked pretty beat.

I figure the only thing left is something in the actual distributor. Does everyone agree? It still cuts in and out for no apparent reason, even after 3 days now. I did take a look at the 2 sets of wires in the distributor that go to the contact points and they look fine. I'm thinking it must be the little box on the side of the distributor. I think they're called ignitors? Anyone else have any ideas? I do have a spare 12A, so I guess I could swap the entire distributor too; maybe thats a better option than the ignitor box... I dunno.

Yes, it sounds like one of your ignitors has gone bad. They're called J-109's and you can find them on eBay from time to time. You also might want to check the Parts For Sale / Wanted > 1st Generation (79-85) forum. Good luck!

Like inittab said, it sounds like an ignitor, probably your leading ignitor. If your trailing ignitor went, your car would be a little down on power, but nothing really earth shattering. Take one of the ignitors off your spare 12A, it doesn't matter wich one, and swap it onto the dizzy in your running car. The leading ignitor is on the front of the distributor, the trailing on the drivers side.

Good luck and let us know how it goes.

PS: how cold is it in Calgary? We've already got down to -20C here. :P

Hmm, I think my 2 ignitors are toward the very front of the car, and then on the passenger side of the distributor, sort of tucked under the alternator. Is that what you meant? The coil that's inactive is the one toward the rear of the car...

Oh, also does each ignitor serve a top/bottom pair of spark plugs? Right now the top plug on the front bank, and the bottom on the rear bank are not firing. Maybe I screwed up the wires when I swapped that rotor. *blush*

It's -22 Celcius in Calgary right now. Supposed to warm up in a bit; I am really glad that Calgary gets the Chinooks.

Ok, so the ignition coils mounted on the fender are arranged so that the trailing coil is closest to the front, so if the rear coil is not firing, that's the leading wich will land you in trouble. The leading coil fires both LOWER plugs on the motor. Leading = Lower, Trailing = Top. The ignitor on the front of the dizzy fires the leading coil, the one under the alternator fires the trailing coil. Sorry for the confusion earlier. ;) The ignitor cap should be labeled, so L1 will go the front lower plug, L2 goes to the rear lower plug, etc. Since you've tried swapping coils with no luck, we have a fair amount of certainty that your ignitor is to blame. Take the ignitor that's on the front of the distributor off and swap it for one from the parts car. That sould solve your problems.

Wow, thanks so much for the info; much obliged. I can't believe I messed up the wires too... My head just wasn't in the game cuz I was so ticked that my car died.

What happenned is I bought a moded gsl-se that puts out pretty decent power. But for the former owner it was just a really fun beater car to drive. From gravel the rear quarter panels were chipped bare where a rock can fly from the tire. So before taking it into the salt I resigned myself to doing the usual paint/rust treatment, cuz if I don't I may as well kiss the body goodbye in 2 years.

I have a plain GSL that still looks pretty decent, but I've been putting off some repair items because in another month I'll be in the SE. It didn't quite make it though; bummer.

Thanks again for the info, I hope to return the favour sometime. I'll report back when I swap those out.

Since you are doing work on your ignition check into converting to direct fire ignition. Do a search on that and you should come up with the info you need or check Paul Yaws web site and he has a good tutorial on the conversion, step by step. I had the same problem and converted while fixing the problem and it makes your engine run smoother.

I'm gonna sell the car in a month anyways, or else park it for a parts car. Either way I just need another month out of it. But my SE might be a candidate for the conversion. I'll do some reading on it... As long as it helps power it's a good thing. :)

Well it's finally fixed. My parts car is a 40 min drive away into the country, so before I left I thought I'd swap the leading and trailing ignitors so that at least I could drive up with the leading plugs firing. Anyways, I swapped the two and the first thing I noticed was that the Tach didn't work... Must work off the trailing ignitor I suppose.

It ran ok for a while (as good as can be expected for 2 plugs :)) but then suddenly cut out. Sure enough, there must have been something wrong in addition to the ignitor, which probably then caused the ignitor to fail.

So I borrowed a car to get up to the parts, and swapped the whole darn distributor. It's working quite nicely now. In the past few days I've changed out my whole ignition system. lol