Saab: Electronics shut down then engine wont start, Saab Fuel delivery problem

Question
QUESTION: I have a 19998 Saab 900s which recently has started to simply shut down it's electronics and stop the engine. This has happened on the highway as well as refusing to start after driving a short distance. During this period neither the indicators, power windows or roof will operate. Strangely after waiting anywhere between 30 mins to a couple of hours the problem goes away and the motor starts without any issues. This seems to happens on a regular basis of between 7 - 10 day period. I have purchase a new 650cca battery.



ANSWER: Andrew:

 It sounds like a heat related electrical connection problem somewhere in the primary (close to the battery/alternator) circuits.Since, as noted in my profile, I have not had hands-on experience with your model, I can only offer general advice.If you are so inclined, I recommend subscribing to the site <www.alldatadiy.com> for the most complete source of information on your vehicle. It costs $25US/year/vehicle, but is well worth it.Unfortunately, because of the intermittent nature of the problem, you'll need to wait until it occurs, and then quickly do the voltage/continuity checking with a voltmeter or equivalent. Because so much is affected, the fault can only be in a few places...from the battery to the main power relay. Also, the ignition switch could be at fault.If you can read and understand a schematic diagram, you'll be able to localize the problem ahead of time, given the symptoms.

         Hope this helps a bit,
         Jerry

---------- FOLLOW-UP ----------

QUESTION: Thank you.

Unfortunately I have not been able to start the car this time since emailing my question. I do however seem to have full electrics in that everything seems to be operational. I have replaced the rotar, leads and spark plugs and am enjoying a very healthy spark, but unfortunately it wont kick over. No problems with my battery or starter motor. I now am thinking perhaps fuel pump or filter based on the logic that if I have battery, power and good spark then it should start. It would appear maybe the only ingredient not present maybe fuel. I'm considering putting a little fuel down into each spark plug socket to see if i get ignition and it starts that then may point it to a fuel delievery fault. Your thopught would be greatly appreciated Jerry. Thanks from down under. Andrew

Answer
Andrew:
  This set of symptoms suggests a weak fuel pump. They often show signs of failure by requiring a higher than usual start voltage...when you crank the engine, the voltage reaching the fuel pump typically drops........could be as low as 9 volts, insufficient to get it running.
 A good test of this possibility is to run a long wire directly from the battery to the "plus" terminal of the fuel pump (on the older SAABS it is beneath the floor). If it starts, then voila! a new fuel pump is needed.
  Jerry