suddenly engine cut out, as if out of fuel (but have 1/2 tank): now wont start

[silver2u]

after having a 900GLi for more then 20yrs (which was very reliable), i purchased 6 months ago a 95 linear 2.3t automatic station wagon (my04) with 90.000 km on the clock (manual versions of the 95 are very hard to find here)

sadly, my nice "new" 95 suddenly cut out yesterday when i was driving at about 50 km in suburbia. no warning lights, no strange noises, no odd smells etc. It felt as if i had run out of fuel, and the engine suddenly cut out (but i have 1/2 a tank). when now trying to start the engine, it turns over well and seems/sounds healthy, but simply wont start (it doesnt splutter or cough either etc), again behaving as of out of fuel (or some electronic/electrical fault ?).

Initially i thought i could not hear the fuel pump engaging, but the RAC callout guy was thorough enough to check this and disconnected the connection at the fuel filter and confirmed it was pumping fuel. He also used a generic Tech2 (obd2 ?) tool to look for fault codes, but none showed (but i dont think he has the full saab software on it, so might not have shown all saab specific codes). I had the car towed home, but am stuck now without access to a mechanic for 2 weeks (due to the Christmas holiday period) and do need the car in the meanwhile. I also havnt found a good trustworthy saab mechanic for a few yrs, and giving the car to a major saab service center would probably be very expensive.

with the old 900 i did most servicing and minor repairs myself, but with all the electronic components on this newer model i am at a bit of a loss of what to look for.

i have checked the more obvious things i can think of.
- no obvious fault codes on dash info or with the RAC tech2 tester
- fuses for fuel system seem ok
- note: even with repeated attempts at starting the engine now, it doesnt smell of fuel or "flooding" which i find a bit odd
- cant see anything obvious that is disconnected in the engine bay (electrical or mechanical)
- i had a look at the DIC (undid torx and removed it) but cant see anything very obviously wrong with it, no bad electronic/electrical smells and no signs of leaks or corrosion.it is a saab original part (0639, so from 2006 week 39 ?)

any ideas or suggestions on what i can check or look for ?

[nordwulf]

I would start with checking all the vacuum hoses. I had one come off once while driving and it showed the same symptoms you're describing.

A faulty DIC usually triggers a check engine code so most likely not the problem. Perhaps a good idea to pull the spark plugs and check the condition?

I think a faulty Crankshaft Positioning Sensor could also cause a problem like this.

[silver2u]

thanks for the quick reply and suggestions.

would a fault in the crankshaft positioning sensor show up on the tech2 tester ?

i have read on the forum there is a way to test the DIC (if you dont have a spare set to replace it with), but i am a bit afraid to use the method and risk doing further damage to the car in the process of testing with this method.

from what i read it is done by:
- removing the DIC from the engine ( keeping it connected to the connector), inverting it,
- placing the spark plugs in each slot, and then connecting a lead from each of the 4 plug ends to an earth point on the car,
- and then turning on the ignition, observing if it sparks on each of the 4 connections

sounds a bit radical to me i'd hate to do further damage with this type of diagnostic process

[DeviousByNature]

thanks for the quick reply and suggestions.

would a fault in the crankshaft positioning sensor show up on the tech2 tester ?

i have read on the forum there is a way to test the DIC (if you dont have a spare set to replace it with), but i am a bit afraid to use the method and risk doing further damage to the car in the process of testing with this method.

from what i read it is done by:
- removing the DIC from the engine ( keeping it connected to the connector), inverting it,
- placing the spark plugs in each slot, and then connecting a lead from each of the 4 plug ends to an earth point on the car,
- and then turning on the ignition, observing if it sparks on each of the 4 connections

sounds a bit radical to me i'd hate to do further damage with this type of diagnostic process

Actually this works very well, this is how we faulted ours and replaced it with a 100% fix to the problem. Buy a roll of speaker wire, leave the DIC or ( Ignition Cassette ) Plugged into the harness but inverted on your head, pull your plugs, put them in the cassette and strip some speaker wire bare every 5-6 inches with about 3-4 inches of bare wire between each gap in the wire, wire each plug together at the thread ( metal base of the plug ) in unison on a single wire then straight to the ground of the battery, Have some one turn the car over a few times while you watch. The Cassette runs on a burst fire sequence where all the plugs should fire at the same time, any fluctuations between them or none not sparking, ur cassette is shot. every plug in sabb engines fires twice per piston cycle, one at the top for combustion and once at the bottom to clear vapor during the exhaust stroke. From what you are describing I would say it could be your DIC or possibly your ECU. I would also recommend checking the ground wires to your intake manifold, transmission and chassis as these also can cause abrupt engine failure with little to no notice if lose or corroded.
On a side note a Faulty CPS ( Crank Position Sensor ) Will not always throw a code. However the symptoms are very set and obvious & non are complete failure. Best tale tale to a bad CPS is the car will crank slowly but run great and soon as its warm it will spit sputter then die, You can keep trying to crank it but it wont stay running, however if you give the engine a few hours to cool it will crank slowly and run fine again for a bit with the same final result of sputtering death.

[silver2u]

Actually this works very well, this is how we faulted ours and replaced it with a 100% fix to the problem. Buy a roll of speaker wire, leave the DIC or ( Ignition Cassette ) Plugged into the harness but inverted on your head, pull your plugs, put them in the cassette and strip some speaker wire bare every 5-6 inches with about 3-4 inches of bare wire between each gap in the wire, wire each plug together at the thread ( metal base of the plug ) in unison on a single wire then straight to the ground of the battery, Have some one turn the car over a few times while you watch. The Cassette runs on a burst fire sequence where all the plugs should fire at the same time, any fluctuations between them or none not sparking, ur cassette is shot.thanks for your detailed answer

i have just tried this, and i think i wired it up correctly. only had enough copper wire stripped on my thick line of speaker wire to "wrap around" each spark plug thread once (but had firm contact on all). the wire i used was fairly thick speaker wire made up of many mini strands of copper wiring, and it covered about half the threaded area of each plug )

when i then briefly crank the car over (as if briefly trying to start it for a couple of sec, not just on/off), all the engine does is make a strong "wheezing" sound, but i cant see any sparks at all on any of the 4 plugs. i had to do it on my own while sitting in the cabin to turn the key, but it was dark outside and i had a clear view of the inverted DIC with the lead running from plug to plug and then to the battery -ve.

so no sparking at all at the DIC on any of the plugs

could there be another electrical component (or connection) before the DIC that could be the cause ? eg causing no electrical supply to the DIC .


note: before trying this method, i noticed that when i initially turn the key to try and start the engine many of the dash lights come on (as is normal, oil light, brakes battery , engine etc..), but as i am cranking the engine most of those lights go off again but the "check engine" light on the dash still stays on (which i hadnt noticed at first, but was probably there all along since this breakdown started). there was however no error code seen on the generic tech2 diagnostic device that the RAC breakdown guy used on the 1e day (which i thought should have shown a DIC error if it was faulty ?). the tech2 however was a generic one that works on many car makes and models, not just saab (but does GM etc)

i went down the car wreckers to hunt for a test DIC unit (black), but only found several red DIC's, all the black units on late models 95's had already been removed.

also checked whatever vacuum or air hoses i could locate on the engine to see if anything had come loose, or if any electrical components, connections or wires were loose, but couldnt find any problems. i'll try and figure out where the ECU is located, and see if i can locate those specific earth wires.

[bobthebuilder]

I keep a spare DIC and torx screwdriver in the trunk for my '04 Arc. Never had to use it, but I've read a lot about this very thing happening and the DIC as the likely culprit. I picked up a DIC at the local pull your own junkyard for $30. Tested it in my car to confirm it is good, then tossed it in the trunk. Takes 3 minutes to swap it out. Did the same for my daughter's 9-3 and taught her how to swap it out.

[silver2u]

it is now confirmed my fault is indeed from the DIC

a friend came around today with a spare DIC unit, and my car started immediately and now runs well again ! As a surprise bonus I can use this DIC for a few days till the new replacement unit arrives that mike is sending me

thanks to everybody for their constructive input, and especially to mike for sending me the replacement OEM DIC (should be here in a week or so hopefully)

[pisani01]

That is what I have found to keep a spare in the trunk ..it happened to me at Wal-mart ...but the strange thins is after I changed the dic a few days later I changed out the dic again and was going to throw it away but it started the car and so i left it in and it has been three months no problem weird huh?