Car cutting out, Now FIXED -thanks!, Looking forward to meeting up at the Ramble Options

[Doug Leggins]

This one has me puzzled. My car runs absolutely great most of the time. Has good drivability around town in stop and go traffic. Is a freakin blast in 3rd gear at 4500 – 5000 RPM though the twistys. It normally runs just like it should in any gear at any RPM. But... it has developed this nasty habit of cutting out at random times. It first occurred back in July when I was driving to the Porsches to Oxford event. I left my house and had been driving along for around 25 minutes, I was cruising along at about 50 miles an hour and it cut out and sounded like it was running on 1 or 2 cylinders. I pulled into a lot and feathered the throttle. It sputtered for 5 seconds or so and then started running fine, just like it should run. I shut the car off and it started right back up like nothing had happened. I got back on the road to Oxford. About one and a half hours later it did it again. This time I was driving around at about 30 mph. It sputtered, kept running poorly for about 5 seconds (again sounding like it was running on 1 or 2 cylinders). I feathered the throttle a few times and it came right out of it and started running fine.

This type of cutting out is still randomly occurring. It will sputter for 5 seconds or so and then come out of it. Or, sometimes the feathering of the throttle will not bring it out of the sputtering and it will die or I will shut it off. It will usually start back up after cranking on the starter for 6-8 seconds (That kind of cranking that seems like winding the car up and eventually it builds up enough desire that it starts.) Usually it starts up and sounds like its running on 1-2 cylinders. After this type of “wind it up” starting 2 or 3 times, it will start up and be running just fine. Then back on the road....

I haven’t been able to determine any pattern other than it will continue to happen until I fix something.

The details of what I am working with: 2056 built by Jake some years back, dual Weber 40’s, Mallory Uni-Lite distributor, Facet Fuel pump, MSD 6AL.

Here’s what I’ve done so far: replaced the fuel filter, installed new facet fuel pump, installed new Aurora plug wires ( I had them and thought maybe it would help), sync’d the carbs. I bought carb rebuild kits but haven’t rebuilt the carbs yet. Thought I’d check with you all for other ideas before I rebuilt the carbs.

Any ideas on what could be causing the cutting out?

Oh yea, one more thing that occurred 2 times tonight while test driving. The car backfired out of the exhaust 3-4 times in rapid succession in about a second or two. Then the car ran just fine after that.

I sure could use some help on this one. I can’t drive it like this to the Rocket City Ramble.

[Doug Leggins]

I swapped out the coil. It did have a Pertronix Flame Thrower coil. The short epoxy filled one that is vibration resistant. It now has a Bosch Blue coil.

I went for a drive and it started acting up after about 14 miles. Loss of power/sputtering for 1- 2 seconds while cruising along at 50 mph.Then started running just fine again. It does seem to be a bit less responsive at around 2700 - 3500 RPM with the Bosch Coil. Seems to sort of sputter a little until reaching about 4000 RPM. Also had the rapid succession of 3-4 backfires out the exhaust while cruising at about 45. Then started running fine again. And one more backfire session after slowing down to turn onto another road and pull up a hill. Backfires, no power for 1-2 seconds (One of those oh-shit moments, in the middle of a hill car dying out of course with a car right behind me.) and then running fine again.

I also pulled the distributor cap and all looked well and dry. No water should be present in the fuel. I ran it out of gas yesterday while running in the garage. So it now has fresh fuel.

I jiggled the wires around a bit and can make the coil jump spark from the center tower wire to the positive terminal. Didn't seem to make the car run any different just jump spark. I can improve the connection here to prevent the spark jump.

One more thing that I did yesterday was change the main jets from 130 to 125. Trying to get the car to run not so rich.

I am now considering bypassing the MSD. And then if necessary the carb rebuild is next on the list.

Any more ideas?