Very weird running problem

[David Pettengell]

will try that today. Is another option to take a jumper from the regulator to the coil to bypass any bad connection as a check?

[David Jones]

Yes, B+ on the regulator is essentially taking a feed directly from the battery.

[David Pettengell]

Tried new coil, jumper from regulator, nothing helped. It's over to PRS

[Steve Douglas]

I had the same problem the car would start and run, but sometimes it would run very poorly, other times it would run great. It happened on a trip to the Norths/South meet, along CA Highway #1. It seemed to be temperature sensitive, in the 60's it would run better, in the 70's it would almost stop.
Tried everything, carbs, distributor, condenser, plug wires. The 2nd evening we decided to go out, turned the headlights on and the car almost died, and if the lights were on it wouldn't restart. To get home I made up a jumper wire run from the B+ on the regulator to the hot side of the coil. The car ran fine all the way. Replaced the ignition, no improvement. Started checking the voltage at the coil, cool mornings was getting about 5.8 volts, but in the warm afternoon only 2.4 volts. Started tracking back looking for something dropping the voltage. Turned out to be the #2 fuse, that supplies the headlight and ignition switch. The fuse looked Ok but had a small crack in the copper conductor, when it got warm it opened up slightly causing resistance, the draw of the headlights heated up fuse so it pulled apart. Check the voltage to the coil with the lights on and the ignition on, you may find the problem. It could also be in the fuse box connections, loosen the set screws and retighten, use some contact cleaner as well. Check out the wiring diagram, go through the current path from the coil back to the battery, using a voltmeter looking for the "drop".

[C J Murray]

A bad connection at the starter solenoid where the B+ wire from the regulator shares a post with the positive battery cable could be intermittent, loose, poorly crimped. Do remember the starting issues!!! Maybe we have a multitude of bad wires or bad connections???

[David Pettengell]

Could be, going to let PRS take a look, they have to be smarter than me and nearly as smart as you !

[David Pettengell]

So... update.

Had a call from Paul today and I was shocked. Looks like my car is running very rich. They tried leaning it out with the mixture screws but still very rich. They are thinking it is due to the car being tuned to US fuel and now it is back in the UK on 97 super fuel it is way too rich.

So it's off to the dyno for sorting. I emailed Cliff as I couldn't understand why I was getting the intermittent spark issues but CJ reminded me that if a plug is fouled the spark will not go down the HT lead!

[David Jones]

What I said at the beginning of this thread.

David, you mention that the plugs are coking up which suggests to me that you are running very rich and probably excessively so at idle. Are you by chance seeking out ethanol free petrol after your engine was tuned on 10% ethanol in the states? Just a thought as some engines can be particularly sensitive to fuel changes especially well tuned ones. Did Cliff dial it in on a dyno?

[David Pettengell]

David, as we get to know each other you will note I am really dumb

[David Jones]

We all have our areas of expertise and total incompetence. Just ask my wife.

[Jim Liberty]

David, we must be married to the same woman. A FYI for all. I installed an alternator on my B Coupe. Broke two pulleys on the way back from an "Outlaws" event last week. After the fact checking (My normal method) the upper pulley is not aligned with the lower. Speaking of DUMB, I checked it after two failures. Yes, my wife was with me and she sat in 90+ heat while I fixed it. Oh boy, in trouble AGAIN.

[Martin Benade]

Jim, are you sure the pulley halves were clamped tightly (enough washers)? My pulleys were misaligned for many years and just wore the belt a little faster than normal. It has recently been fixed, but never a cracked pulley.

[Gary Cox]

Yea, Jim, three out of four time when I try to improve on original design, I soon regret it and convert it back to the way it was intended. Hope to soon learn not to even attempt such nonsense.

[Jim Liberty]

The bearings on the alternator went south. Had it repaired and back in the car. The belt may have been too tight, I added two shims, and will hope for the best. I don't plan any long trips in the near future. All of your comments are "Right On" thanks.

[C J Murray]

Jim, which alternator conversion do you have? Is it a VW alternator or the Brit unit?