We've got a 1990 Volvo 740 that has an intermittant no start problem which began about a month ago. Am pretty frustrated with this problem. Engine is B230 with 128k miles. Symptoms began with occasional no start. Engine would crank; no ignition though. When engine would turn over, car ran fine. No start condition occurs most frequently after short drives, literally around the block. Turn the engine off and it fails to restart. Let it sit overnight and it tends to restart in the morning. Latest symptom was that engine seemed to cut out while accelerating up local high-rise bridge. Sounded like engine quit, sputtered then came back to life. Engine also recently quit while waiting at red light, but restarted after several tries.

I've replaced a number of parts but problem persists:
spark plugs, plug and coil wires, crankshaft sensor, and RSR relay. Fuel pump fuse is ok.

A mechanic friend swapped out fuel pump relay with a new one off the shelf but problem continued. Mechanic says fuel system pressures are right on specs. Last week he determined that there was no pulse to the injectors when no start situation occurs. He thinks next thing to do is replace the computers both of which are Bendix not Bosche.

Has anyone out there experienced similar no start problems?? Any ideas for my next course of action? Should i go ahead and replace computers? The fuel injection computer before the ignition computer? Are used Bendix computers rare and difficult to find? Any suggestions on sources?

Am very frustrated at this point. Any help will be greatly appreciated.