My 1986 745T won't start. I've gone through every fuse, sensor, every computer module and even replaced the distributor and the coil. Checked and repaired any questionable wiring.

Symptoms:

1. Erratic timing with timing light. Sometimes I get a light pulse to the number one cylinder, sometimes I don't. The timing light is fine (I double checked it on another Volvo). It's like this: turn it over, get several light pulses, then it stops giving light pulses while still cranking. The light strobe marks the same spot on the pulley when it does pulse. The belt and associated pulleys are in the proper alignment.



2. Seems like I have too much pressure in the engine. One time it blew a lot of oil through the breather tube, which I have since pulled and cleaned all associated parts. The next time it popped the oil stick out and oil surged out.

Could it be a problem with the ignition switch circuit?

Thanks,

Bob