The bug is running poorly lately. I assumed it has something to do with the choke. I've fiddled with the carb settings and sometimes it runs okay but most of the time I have to floor the gas pedal to get it moving from a stoplight. Same thing for changing gears. it starts fine every morning but as it warms up the idle will die at stoplights.
In the past in other bugs I had a similar problem that turned out to be a dead cylinder. So while it was idling I pulled the wire from each distributor connection one after the other. Cylinders 3 and 4 did what's normal, that is the idle speed dropped and I had to put the wire back fast or the bug would die. But cylinders 1 and 2 there was no change in idle with the wires pulled off. It continued to idle steadily.
But I could see electrical arcs going from the wire to the distributor connection. Does that mean there's electricity getting to the plugs? Or will fouled plugs still have that arc at the distributor?
I bought the vacuum distributor less than a year ago from Cal imports and replaced the capacitor induction unit six months ago.
TIA,
kevin
Running poorly, electrical problem?
- Marc
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Re: Running poorly, electrical problem?
Yes. A "fouled" plug is simply one which has developed a conductive path around the gap, which diverts the current and yields no spark in the cylinder.crvc wrote:...will fouled plugs still have that arc at the distributor?...
The voltage coming from the coil rises at the initiation of each spark event, and if the current finds a path to travel while it's still relatively low all of the energy will follow as the voltage goes up. When you hold a plug wire away from the cap by ~½", the voltage must rise to the point where it's high enough to jump that giant gap before it gets to the plug, so it stands a better chance of making it across the plug gap - that may get the cylinder firing which hopefully will burn off whatever deposits are fouling the plug.
If you hold the throttle open to keep the engine running at 2,000RPM or so, and one by one pull each wire away at the cap, you may find that one or more of the cylinders fire better when the wire is held out than when it's plugged back in - that's a classic sign of a fouled plug (less common, it can also be due to old plug wires that are "bleeding" energy through their insulation).
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Re: Running poorly, electrical problem?
I checked all the plugs and it's not an electrical problem after all. Like I said, when I pull the wire from the distributor at #1 and #2 the idle is unchanged. Someone suggested manifold vacuum leak but I blew off that idea. But when nothing else worked I sprayed the manifold boots with engine starter and on the right side the idle sped up. So I grabbed a screwdriver. The larger of the two hose clamps just turned freely without tightening. I replaced that hose clamp and double checked the other three. All are tight. Timing is set close to 5btdc but the gun's light is so poor that even in the garage with the engine running and the doors closed it's hard to read. I don't know whether this solves the problem but I'll find out tomorrow when I drive the bug to work. I'd test-drive it now but I've got a miserable headache from inhaling exhaust fumes while working in the closed garage with the motor running.
kevin
kevin
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- Posts: 1564
- Joined: Fri Aug 29, 2003 2:37 pm
Re: Running poorly, electrical problem?
Car seems to be running right since replacing the hose clamps on the manifold boots. So it was never an electrical problem.
kevin
kevin