1990 740GL moter shuts down

margie · Post by **margie** » 01 Feb 2004, 13:29

My 740 will shut down on occasion while I am driving.It does not skip it just stops.In a minute or to it will start up and run sometimes for days before it will happen again.The electrics all work.

LaRy · Post by **LaRy** » 13 Feb 2004, 14:06

Check the rpm-meter when the engine shuts down and the car is still moving (dead engine rotating). If the rpm-meter is showing some rpm, ignition is still alive. If rpm = zero, ignition is dead and you know a little more about where to look for the problem. Even when cranking, the rpm-meter should show something like 600 rpm.
If the rpm = zero, it could be the ignition control unit.

Volvord · Post by **Volvord** » 13 Feb 2004, 16:28

Intermitent problems like this can be very difficult to locate.
Some common areas I have seen troubles in order of simple to fix and low costsare:

1) Distributor wiring where it passes under the distributor cap. The gromet will come loose and expose the wires which will short against the distributor housing.

2) Ignition switch, when it dies just try wigging the key in the switch, if this has any effect replace the ignition switch.

3) Hall effects pick-up in the distributor, ignition amplifier.