You could have a problem with the hall sending unit in the distributor or the
ECU itself (it houses the coil driver for the ignition system).  Your dealer
mechanics should be able to troubleshoot your ignition system from the
Bentley Manual (they better have one) in a matter of minutes not hours.  It
just isn't that complicated.  If you do find that you need an ECU I have them
rebuilt for $200.  Hope this helps.

Thanks,
Ken Wilford
Van-Again
John 3:16
http://www.vanagain.com
Office: (856)-765-1583
Fax: (856)-327-2242