SaabCentral Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
83 Posts
Discussion Starter #1
Hopefully someone else has figured this out. 1998 SAAB 900 SE Turbo. Great shape, well maintained. All of a sudden, the crank to start time went from almost immediate to 4-5 seconds on the first start of the day. Even longer. The next start that day is always quicker - maybe 2-3 seconds, but still not like originally. Otherwise, the car runs like a Singer sewing machine. Perfect, smoothe, never stalls, no smoke, good mileage, good boost, etc. I have a new functional Bosch alternator, new charcoal cannister, new battery. I replaced the vacuum line from the Fuel Pressure Sensor. I use 93 octane. Checked fuses and relays. Changed oil. Original fuel pump replaced with new Saab part January 2012. Any thoughts? Fuel? Electrical? HELP!
 

·
Registered
Joined
·
21,583 Posts
One thing many people forget about is the CPS .. on most all cars ...
CPS = crank position sensor.. known to be "good" when old and then fail when hot . I changed mine at 15K or so as preventative maintenance. Use an oscilloscope to test , its signal should be about 2.5 volt and there is an Ohm number as well, forget what it is.
 

·
Registered
Joined
·
304 Posts
I have heard that this time of the year the gasoline formulation changes and the Saabs are sensitive to it when it happens. Takes them a bit to acclimate to the new formula. This is why it takes some extra seconds to start.
 

·
Registered
Joined
·
83 Posts
Discussion Starter #5
Still Too Cranky In the Morning

Hi. Thanks to everyone for the help. I replaced the CPS now, too, but no help there. Still a long crank first start of the day, then better, but not back to normal. Also, on the first start of the day, if I crank and stop, wait, and then crank again, it seems to start quicker. Hmmm... QUESTION: when turning the key to On (not Start), should I hear the fuel pump go on? I hear nothing.
 

·
Registered
Joined
·
108 Posts
It sounds like the fuel pump isn't priming. Mine doesn't seem to either, but my fuel pump is dead. :p

Try bumping the starter just for a second then starting as usual to see of that reduces the cranking time. You can also try probing the fuel pump fuse with a test light. It should light up for a second when the key is turned to on, then shut off. It should also light up when cranking and when the car is running.

I have been diagnosing my fuel pump issue for a few days and have found that it doesn't seem to prime when the key is turn on either. Not sure what would cause the ecu to not prime the system.

Edit: it primes after the car has been sitting several hours, but not if it has been cranked recently. The computer must have timer logic it uses to decide when to prime.
 
1 - 6 of 6 Posts
Top