240 dies instantly - progressive issue getting worse

[pressedsteel]

Not long ago, I was driving my 240 daily. Occasionally, while driving, the tach would drop to zero and instantly revieve - like the car was going to die but didn't. I thought this happened most often over a large bump. After a displaying the above symptom for a couple months, the car would begin to die while idling -- no sputtering just instantly off. At first, it would always restart. Now, I've had to pull it home twice and it basically will not stay running longer than five minutes and is hard to restart. It will start for a split second (sounding really strong) but again die out instantly. It must be an electrical issue but I'm not sure where to start and I'm hoping someone can point me in the right direction. I'd like to repair it myself but I don't like replacing parts on a trial and error basis! Any help would be greatly appreciated. Thanks! Alan

[Arne]

OK, simple tests first. Try hot wiring it to see if it will run consistently when the ignition switch is bypassed. Do this by running a wire from the positive terminal of the battery to the + terminal on the coil. Then try to start the car with the key as normal. See if it runs. If it does, you will need to kill the engine by first turning off the key, then disconnecting your new wire to the coil.

If the problem goes away, it is in the ignition wiring, probably the ignition switch itself. If the problem remains, more testing will be needed.

[EScanlon]

It could also be as simple as the Tach wiring connector being loose. Although that wouldn't account for the 5 minute run time.

Or the Resistor starting to fail. That could account for the 5 minute run time, except that since you've had to tow the car home a couple of times, the resistor would presumably have cooled down enough to re-connect (presumably).

See if Arne's suggestion helps.

E