Hello! I have a '71 Mav, 200 engine. About a year ago, I put in a Pertronix electronic ignition along with the coil that should go with it. I've not driven the car much during the past 12 months. I'm finding the idle is rough-- the timing was checked after I put the Pert in by a professional Ford engine mechanic. I'm wondering if I ought to upgrade the spark plug wires to a thicker diameter, and maybe the spark plugs too. The distributor cap is Motorcraft, so I doubt there's a problem with that. For full disclosure, I've been having a stalling issue, and all evidence indicated that it was the accelerator pump, which I replaced. Prior to doing that, I had the carb professionally rebuilt about two years ago. (The carb is a Carter YF) Bye, Daniel "Renton 5"
Size of plug wires is mostly a bunch of hooey. It's the insulation condition and resistance per foot that's important. It's true older carbon type wires can be "burned up" using high output systems. If engine accelerates normally, there probably isn't anything wrong with ignition system.
The diameter is just the insulation. If your wires are old, replace them, but that's probably not what's causing the problem.
You didn't indicate the age or condition of your wires or plugs. As Krazy Comet explains, wire diameter especially on a stock engine should not be a concern. You also did not write as to whether your stalling issue has been corrected. A bad accelerator pump usually leads to a bog down on initial acceleration rather than a stalling condition. Wires or plugs in bad condition or of poor quality can lead to rough idle, stalling and miss fire.
Hi Everybody! I should've proofread the subject title to read "Spark Plug Wires", fortunately you all knew what I meant! I believe the wires aren't too old, definitely done before putting in the Pert ignition. Also, I don't drive the car very much so I wouldn't think that either the plugs or wires are too worn. I will look at the plugs again. As to the accelerator pump, I'd be at a stop, the engine would be about to die then I'd have to two-foot it to keep it going. Here's the weird part--once the engine was at operating temperature this happens more often than when cold. The car doesn't have AC nor power brakes.
In America bigger is always better. Funny thing is, in the '90s many Jap cars were using spark plug wires of approx five or six mm OR smaller than the original wires of US mfgr in the '50s, 60s & '70s. As already stated, it's type of insulation and conductor that determines quality of wire. In another thread, I mentioned the Clevor I assisted a friend with a month or so ago. The guy he was building it for bought a set of universal 8.2mm wires that we had to cut and install end for dist. That was a miserable job, the boots were too small to fit on wire and we tried two other sets beside what what were shipped with wires. I wound up using a tapered punch to stretch boots so we could force them on. Around a year ago I bought a set of Flame-Thrower 7mm "original look" wires for my Fairlane. Again universal application, those were easy to build.
We tried that stuff and silicone grease to install boots, wasn't happening till after I started stretching them with punch. Worked great on the Flame Throwers.
I install a set of wires a few years ago and had a similiar issue getting boots on. I used silicone, but didn't seem to make much difference. In fact, it made it harder to get a grip on insulation to force boot over wire.
LOL.. no wonder you had problems.. the silicone is supposed to go INSIDE of the plug boot Everett! I always use use a dab of dielectric grease on the end of each spark plug and swab the inside of the boot. MUCH easier to remove later on.
If you don't drive it much I'd suspect the fuel is going stale causing the problems with stalling. Especially if you're putting any grade or percentage of ethanol mixed gas. If that stuff sits a long time in the tank it'll have moisture (water) condensate in the tank. My Comet sits for weeks at a time between startups, I alternate fillups between straight gasoline (less than 5% ethanol) and E10 premium to keep the ratio of ethanol to gasoline down to a minimum. It's worked for years like this without any carb problems.