what would cause me engine to die at speed in my 240? the electrical pump works correctly, and the mechanical pump is a few years old. could it be the mech. pump? ususally when the engine dies, i can restart it immediately and it will run , and sometimes it will die again as soon as i hit the gas pedal. i have made no adjustments to the carbs since my mechanic set them up about 2 years ago. i don't think it's an electrical problem because i just replaced the battery and alternator. (when the engine dies, the radio and lights stay on).

Sounds like one of two things.

If the fuel filter hasn't been changed in a while, it may be clogged. You could be picking up a lot of garbage out of the tank and that is clogging the pickup also.

First thing I would try is to remove the fuel filter and blow air through the lines to remove any sludge or whatever form the pickup. Install a new filter(preferrably a see through) that you can keep and eye on. If it shows a lot of dirt, rust or whatever in a short time, you may need to remove the tank and have it cleaned/re-sealed.

I doubt the fuel pump is the problem as it is a mechanical, once they go, they are gone, period.

Since you didn't say if the car runs rough or stumbles after it stalls out and then re-starts, it is hard to tell if it could also be a vapor lock problem. If it does stumble and run rough, check the water control valve in the back of the intake manifold. Block it off and see if the car runs OK after that, if it cures the rpoblem either leave the line blocked off or get another water control valve.

Since you say you have both an electric and a mechanical pump you could be having an electrical short or loose connection to the electric pump and the mechanical is not drawing the fuel through. Try re-routing the fuel line around the mechanical and just go with the electric. If it still quits, you at least know it is either a blockage in the line or the electric pump is the culprit.

the engine runs great while i'm driving, it doesn't stumble or run rough, but it still cuts off when the engine becomes warm. i have a crane electronic ignition with a crane ps-20 coil that was installed about 5 years ago. i wonder if the ignition could be the problem? i drove it yesterday and it cut off and i couldn't get it cranked until the engine cooled (about 10-15 mins). i don't think it's fuel related because i installed a new fuel filter and it stays clean and i cleaned the filter in the fuel pump. the electric pump runs great also.

Have you tried a different coil? Since you say yours is 5 years old, it is possible it is the coil overheating and that is causing the problem.

I'm with Keith about the coil. Another thing, does it still have the ballast resistor at the coil?? My 73 (stock ignition) had a loose wire at the BR, so it would die intermittently, then run only with the key in the "start" position, till it jiggled enough to make contact.

Definately sounds electrical, not fuel starved though. Good luck, Jeremiah

changed coil and resistor and installed a new filter in the electric pump, and everything seems fine... so far!

after i changed the electric pump and the mechanical pump, the coil and resistor, it still dies! a friend said his old 510 did the same thing and the problem was the ignition itself. he said that when the car cut off the ignition key would be hot., so he changed the ignition and the car did great. i guess i will look into this on my car. i'm running out of options.

Try replacing the capacitor in the distributor.

don't know what the capacitor is, what if i replaced the entire distributor?, it is the original one, or go with a 280z distributor? i just want the car fixed so i can drive it with no worries about it cutting off in traffic.

To change the distributor is a bit of an overkill at this point.

Depending on model the capacitor maybe on the outside of the disrtibutor. Look for a half thumb size thing with 1 wire attached or lift off the distributor cap, the capacitor is opposite the points.

Change either one and cross fingers.

i don't have a capacitor. i removed the points several years ago in favor of electronic ignition. i'll have to check the ignition box when weather here clears up.

Ignore all I written!

Cannot help you.