The car is having trouble starting. Turns over fine but will not start. Seems to be intermittant over the last few days. I have confirmed spark at the plugs and fuel after the pressure regulator. What else can I check?

If you have spark and you know you have proper fuel pressure at the injectors, then the prime suspect is the Radio Suppression Relay.

If you aren't familiar with it:

You should see two relays mounted to the front of the coolant overflow bottle. One is the Radio Suppresion relay (which provides the electrical current to open the injectors) and the other is the aux electric fan relay (which powers the electric fan when the sensor in the radiator says the water is getting too hot). They are identical, therefore you can swap them.

If that cures the problem, you can generally repair the relay by openning it up and resoldering the circuit connections.

additionally you can check that the injectors are firing by laying the tip of a screwdriver on the injector and listening at the end of the screwdriver for pulses.
--
Paul NW Indiana '89 740 Turbo 103,000

Are the plugs wet or dry after trying to start? If dry, I would suspect the radio suppression relay, mounted around the coolant expansion tank.

I did not check to see if the plugs were wet after cranking but I will tonight. Would the radio suppression relay show intermittance performance? I will certainly swap this out tonight as well. Thanks for the advice.

"... Would the radio suppression
relay show intermittance performance? ...

Yes. The one I had to go bad acted just like you desribe your's is doing.

Thank you Chris. That will be the first thing I attack when I get home. I'll let you know how it turns out.