I have a 1970 XKE. It's been sitting for 5 or 6 years. Took out the gas tank, cleaned it all up and the engine is getting plenty of fuel. When I start it up it runs fine and smooth but after 5 or 10 minutes it will start to sputter and backfire and then dies. I put it on the charger wait a couple of minutes and it starts right up. It will run smooth with the charger at 250 amps start position and the 50 amp position but starts to slow down and cough and sputter as I turn the charger off. It seems the higher voltage keeps it going for awhile. evidently dieing anyway. What's going wrong?

 

I'm guessing here, but you could have a short in one of the cells of the battery.... switch batteries and try it,.... a shorted cell can cause a fire

 

I seems I had a bad rotor. I replaced it and it started right up. Now i can run whatever fuel that is bad out and get myself over to a shop and get the weber's tuned. Thanks

 

Right now it starts right up but runs a little rough. After about 10 miles it strats running rougher and bogs down when any load is put on it. I'm having a hard time finding someone to work on Webers Carbs, but I'm working on it. In checking the timing mark it's way off to the right of the pointer and when I move the dizzy the engine stalls. Any help is appreaciated.

 

If you rotate the distributor further to the right does it speed up? If so, that is the advance direction.

It may be that a previous owner was trying to compensate for a seized up centrifugal or vacuum advance mechanism ... so they used lots of static advance. Or, it seized up in the five years of storage. Should be easy to pull apart, clean and lubricate.

It may also be that someone installed the distributor in the wrong position.

Testing the advance mechanisms is easy if you have a timing light.

 

I had a similar problem once. The car would run fine for a short while, then sputter and die.
Turned out to be a bad winding in the electric fuel pump. When the pump heated up to a certain point, the broken wire in the coil winding would separate just enough to short out the pump. I replaced everything electrical, until I figured out the pump had a coil in it too!

 

I took the car to a weber mechanic. One of the floats was bad. I installed new wires coil, cap and plugs. It runs like a champ now. Plenty of power and purr's like a jaguar should. Now it's on to the oil leaks that the new power is causing. Aren't they fun.