I still haven't figured out the cause of my daughter's 740 wagon (210,000 mi.) intermittent no start problem. It has started the last two mornings. Yesterday it failed to start a few hours later after it had started in the morning. It is currently starting every time I try it.

I have tried to wiggle the RPM sensor wires (whose outer, black insulation is coming off of the two seemingly well insulated wires that were inside the bad outer insulation).

FWIW the last time it failed to start (yesterday) I replaced the ignition coil and the ECU neither of which brought the car to a starting condition. With those parts in the vehicle it started this morning (as it had done yesterday with the original coil and ECU in it). I was suspicious of moisture related problem but yesterday morning when it did start it had rained the night before so I'm not so sure about that anymore.

Should I check anything while it is running that might help me to know what the problem is when it's not running?

Or should I just wait until it fails again and continue to try different things?


It's a Rex Regina system, I have good spark and I've sprayed in starting fluid while cranking to no avail. I'm still suspicious of the fuel side of the problem - I have to wonder if it is a fuel pressure problem. I don't have the plumbing parts necessary to test fuel pressure when it won't start...

I may have a 700 for sale soon as my daughter is looking into a '96 Olds 88. Of course I'd rather her stay with her 740 but I have to let it go as she is now an adult (I hate it when that happens :-)

thanks to everyone who have weighed in to try to help me with this one!