Questions about ignition coils etc intermittent issue

[The13bats]

I dont want to give too much details yet to avoid leading and confusing, im curious has anyone had an ignition coil go in and out, in other words the vehicle might run sweet for hours then get all crappy like bad fire in the wire then after you restart it might clear up, the coil bench tests okay.

How about those electronic modules that replace points, ever heard of them running great then crappy, then out of no where runs great again,

thanks
b

[Gene]

If you are having a problem with an ignition system going from good to bad, then back to good again, I think I would be looking at the wiring pretty close. I suspect you have a wire or a wire terminal about to break or really corroded, probably only has a few strands of the wire still connected or still making contact.

That said, there are many issues involving electronic ignitions, and even point ignition systems that are brand specific. GM, Ford, Mopar and nearly every other manufacturers ignition systems have some issues that are only related to the specific manufacturer.

On top of all that, parts break down and wear out. Nothing made by man lasts forever, and every design has faults, there is no such thing as perfection with man made things.

If you would like to be specific as to what your problem may be and what your working on, we may be able to help. Gene

[The13bats]

Thanks Gene, okay, ill get long winded, ive been putzing with vw stuff buggies, kit cars , trikes over 40 years and this issue is baffling, im missing something, the gremlin is a mean one, onbthis glorified lawn mower engine.

The vehicle is a volkswagen trike, 1600 dual port, pict 34 3 carb svda distributor, dual buggy style exhaust, the plugs are good, plug wires test good, no leaks in the dark either, the cap and rotor are good and timing is set to spec.

Keep it mind it did run great for years.

The issue came on slowly and due to my health and life i dont ride it that much and mess with it here and there, but im on it now to figure out this mystery.

so it started as what one might think was fouled plugs, it would run rough raggedy but normally clear itself up as you rode it a while ( 30 min ) the issue was odd even after cleared if you were running say 40 mph in 3rd and down shifted it would act really nasty.
that caused me to question the electric fuel pump pressure so i installed a regulator set to spec it did fix that issue of running rough coming off higher speed.
however,

then it got worse it would stumble want to die and act really nasty, buck etc, it would clear up out of no where, or persist until i would give up and park it, then many times on restart or after being parked it would start and run sweet but only for a spell.

So i rebuilt the carb which was clean, its adjusted correcly, it seemed to fix it then came back, so i tried a different coil, 4 coils in total, all test good, sometimes it would seem like it fixed it then back it came, it does run a hair different on each coil.

The dizzy had a cheap electronic module so i swapped it out for old school points which again for a little while helped then dammit man, the issue comes right back, as bad as ever,

The intermittent coming and going is nerve wracking to try to pin down, tonight it never cleared up and the biggest clue i have is it will be idling crappy, but when you start to move the throttle it will want to die or will die if you get past the off idle it runs crappy but doesnt die. vacuum issue?

I have checked best i good for vacuum leaks with carb spray and just do not detect any, theres not a lot of places for these to leak vacuum, i am gonna go at testing it a bit harder but i dont really believe its leaking on and off intermittently.

and as your legitmate concerns on wiring i have seen and helped sort out some real messes. i just rewired it again, im very OCD i love automotive wiring and knew i could do better, cleaner than i did years back when i got it, the problem was there before and after rewiring,
I have designated circuits going to fuel pump and coil so they get good 12v.

im missing something, but like dad ( rip ) used to say no vehicle problem can outsmart you no matter how hard it tries to.

Many thanks,
b

[Gene]

How old is the gas in your tank? Old gas does some strange stuff.
Your problem sounds like a fuel related issue more then an ignition issue. A fuel problem can change from day to day, or minute to minute.
I had a ride once that drove me crazy. It would run great, then out of the blue it would die. A few minutes later it may, or may not run, or it might run great for a short time, then run really bad. Turned out to be a leaf floating around in the gas tank! At times the leaf would float around and not cause a problem, but other times it would float over to the fuel pickup in the tank and close off the fuel to the pickup. Found it pretty much by accident, one time I was filling the tank and the leaf floated up to where I could see something in the tank. Removed the leaf and the thing ran great. Not saying that is your problem, but it was something I encountered. Gene

[GeneP]

Just for Chits & Giggles look real hard at the plug wires. Few years back I had a 455 Olds in a jet boat real 90 mph screamer (When it ran). It would run great then out of the blue when above 2,500 RPM it would intermittently run on 7, 6,, then 4 cylinders for no apparent reason. Come back to idle and it would clear then shortly after the problem came back. Took me 2 years of frustration tearing stuff apart & replacing stuff to discover Brand New Taylor wires were bad. Don't assume nothin....