Odd warm starting problem

[echrisconnor]

The weather has started to get warm, and with it...new problems. The first time I figured it was a fluke, but now that it has happended three times in a row, it's a problem.

For starters, the car is a 2000 9-5 2.3t wagon. When I drive the car for a short period of time, say about 5 minutes, and park it for a short period of time, say 5-10 minutes, when I come back it won't start. So, for example I run to the store, grab something quickly and come back out and I get a no-start. All the electrics fire up, all the diagnostics clear. I even think I can hear the fuel pump go on, but the starter doesn't turn.

I've tried wiggling the shifter, moving it inbetween gears, getting in and out, locking and unlocking, arming and disarming the alarm but none of that works. The only cure seems to be time. The first incident, it only needed 2-3 minutes until it would start. The second time it needed about 7 minutes. The third... about 45 minutes (and two beers for me). I don't have this problem after a long run and a longer cool down period.

Any advice would be appreciated.


chris

[Al's Red Wagon]

I've tried wiggling the shifter, moving it inbetween gears, getting in and out, locking and unlocking, arming and disarming the alarm but none of that works.

Sounds like you may have ruled out the Neutral position lockout...

The only cure seems to be time. The first incident, it only needed 2-3 minutes until it would start. The second time it needed about 7 minutes.

Sounds like a classic Crank shaft position sensor problem. It gets blinded if it is too hot and this problem gets increasingly worse with older sensors...

The third... about 45 minutes (and two beers for me).

Good solution!
Here is another solution found in the FAQ's:
Crankshaft Position Sensor - Stalling

Couldn't tell where your car is from your profile...
so part for the UK: http://www.partsforsaabs.com/product...oducts_id=2833

And in the US:http://www.thesaabsite.com/shop/sear...1=Start+Search

[Kermit]

Originally Posted by Al's Red Wagon

Couldn't tell where your car is from your profile...

Profile says its a 2000 "wagon" which means he's US based. It would be an "estate" if he was a fellow "limey".

[Chris 9-5]

Originally Posted by Kermit

Profile says its a 2000 "wagon" which means he's US based. It would be an "estate" if he was a fellow "limey".

So he gets a bargain CPS

Thank fully we get cheap......... erm....... oh.................... ah

[echrisconnor]

Hey, thanks all.

I've done crank position sensors on some of the Motronic Porsches I've played with in the past. Those things can really make for some erratic problems. So let me ask this. Why then on a warm car (not hot) does this happen? After a longer drive, it seems to always fires right up again. I dread changing this

I'll look into this some more, but it does seem like some sort of defeat is in place. The neutral lockout is what I first thought, but I wouldn't expect for time to help this. As for the CPS, I'd expect it to fail after the long drive, but not necessarily after a short one.

Again, thanks for the feedback.

chris

[Al's Red Wagon]

Originally Posted by Kermit

Profile says its a 2000 "wagon" which means he's US based. It would be an "estate" if he was a fellow "limey".

That's why you were a moderator....

I'll look into this some more, but it does seem like some sort of defeat is in place. The neutral lockout is what I first thought, but I wouldn't expect for time to help this. As for the CPS, I'd expect it to fail after the long drive, but not necessarily after a short one.

I'm no expert so the following doesn't make a whole lot of sense to me:

Originally Posted by W.I.S.

The control module receives information on the position and speed of the crankshaft on pins17 and 18 from the crankshaft position sensor. There is a slotted ring with 58 ribs on the crankshaft. The sensor is of the inductive type and is fitted to the wall of the engine crankcase. The distance between the sensor and the slotted ring is between 0.4-1.3 mm and is not adjustable.
The sensor functions like a generator and delivers a sinus-wave alternating voltage. Bymeasuring the frequency, the control module can determine the engine speed. There are 2 ribs missing after the 58th one. When rib 1 then passes the sensor, the control module knows that the crankshaft is 117° before top dead centre (BTDC).
The voltage from the crankshaft position sensor varies with the engine speed. At idling speed, the voltage is 5-10 V (AC) and at 2500 rpm, 15-20 V (AC). However, it is the frequency and not the voltage that is of interest to the control module.
As soon as the control module receives pulses from the crankshaft position sensor, it will ground the fuel pump relay.
Sensor resistance is 860±90 ohms.
Engine speed is used to:
• Indicate the engine operating point in conjunction with the engine load. The operating point indicates the values to be used in matrices and tables.

System reaction to a fault
• Regulate the idling speed.The crankshaft angle is used to calculate when angle-related functions should be activated,such as ignition, injection and knock detection.
Diagnostics
• If the crankshaft position sensor is defective during starter motor cranking,diagnostic trouble code P0337 will be generated.
• If the control module loses track of the crankshaft position while the engine isrunning, diagnostic trouble code P0336 will be generated.
• There is no substitute value for the crankshaft position sensor.

I've bolded what seems important to me... Basically if the sensor is blind the fuel pump relay doesn't get grounded.

Many folks have fixed your issue by swapping the CPS and not even checking for a code....I think noone checks because the CEL isn't on once the car starts and doesn't look like anything different when the car doesn't start... I'm also skeptical about wheter it throws a code each time it malfunctions or not...

[Chris 9-5]

Originally Posted by Al's Red Wagon

Many folks have fixed your issue by swapping the CPS and not even checking for a code....I think noone checks because the CEL isn't on once the car starts and doesn't look like anything different when the car doesn't start... I'm also skeptical about wheter it throws a code each time it malfunctions or not...

The CPS does not throw a code when it fails.

[Al's Red Wagon]

Originally Posted by Chris 9-5

The CPS does not throw a code when it fails.

I guess that was my point.... I think it's supposed to though:

Diagnostics
• If the crankshaft position sensor is defective during starter motor cranking,diagnostic trouble code P0337 will be generated.
• If the control module loses track of the crankshaft position while the engine isrunning, diagnostic trouble code P0336 will be generated.

[echrisconnor]

I need to check again, but I swear I heard the fuel pump running when I turned the ignition on. I don't know if that's possible and it may have been some other motor going, but it sounded like the fuel pump. If the CPS needs to be functioning in order to run the fuel pump, does this affect the diagnosis?

Also, is CPS failure attributed to stalling? Mine doesn't stall, just the no-start situation. Also to be clear, the starter does not crank. The car does not turn over at all when the key is turned. When I've had Motronic CPS issues, the car will crank but not start.

chris

[Skipshot]

You are not alone with your starting problem, as I have the exact same symptoms. Irritatingly, the problem is sporadic but always after the engine is plenty warm, and twice I got stuck in a car wash. I'll try replacing the CPS.

[echrisconnor]

Skipshot,

With your problem, does the car crank but not start, or do you just turn the key and get nothing at all?

chris

[Skipshot]

chris, I get nothing at all. All the lights go on and the SID shows the engine is OK, but the starter won't turn over. I usually have to wait about 10-15 minutes before the starter will turn over.

Is this a CPS problem?

[rjcipperly]

Hi: What has happened so far after your problem solving..............did you ever get this resolved
thanks
Rjcipperly@adelphia.net

Originally Posted by Skipshot

chris, I get nothing at all. All the lights go on and the SID shows the engine is OK, but the starter won't turn over. I usually have to wait about 10-15 minutes before the starter will turn over.

Is this a CPS problem?

[Skipshot]

Haven't worked on it yet because I've been on vacation. The car needs regular service anyway, so I'll ask my mechanic to replace it while he's in there.

[nbndtrain]

Originally Posted by Skipshot

chris, I get nothing at all. All the lights go on and the SID shows the engine is OK, but the starter won't turn over. I usually have to wait about 10-15 minutes before the starter will turn over.

Is this a CPS problem?

This does not sound like a CPS problem. With a bad CPS the engine will crank but not turn over.

[Skipshot]

Originally Posted by nbndtrain

This does not sound like a CPS problem. With a bad CPS the engine will crank but not turn over.

Thanks. What do you suppose it could be?

[echrisconnor]

The problem hasn't occurred again. My hunch (although unfounded) is that it was an alarm anomaly. I would have thought it was a shifter lockout thing, but think I ruled that out. Still waiting for the next occurrance... tick tock \

ps. I have not changed the CPS

[rjcipperly]

The last note to me was to check the positive cable going to the starter.......who knows, but it is an easy thing to verify that it is tight...tick,tick


thanks again

Originally Posted by echrisconnor

The problem hasn't occurred again. My hunch (although unfounded) is that it was an alarm anomaly. I would have thought it was a shifter lockout thing, but think I ruled that out. Still waiting for the next occurrance... tick tock \

ps. I have not changed the CPS

[duramax2002]

I had this same problem with intermitent no starts (starter not turning) after short trips. Long rides and car would restart fine. The problem was my park/nuetral switch in transmission. May or may not be your problem but here is how to find out. In the fuse panel on the drivers side (you will see it when you open the door) the 4th row down 2nd fuse from the right is a 7.5 amp fuse, this is from the ignition switch, when the car fails to start check to make sure that when you turn the key there is 12 volts on this fuse (with ignition switch all the way clockwise), if not ignition switch problem. This 12vdc is what closes the start relay under the dash on the drivers side (saab calls it relay 517) if you take the screw out of the relay card and drop it down it will be the big relay bottom row). Before it can close this relay it goes through the transmission P/N switch(this is where I lost the 12vdc), also there is one other thing that can keep this relay from pulling in and that is if the relay coil does not have a ground, the ground comes from the anti theft key recognition. So if there is 12 vdc to the blue wire (back side of relay card)then check the blue and white wire and make sure there is not 12vdc(if you see 12vdc then there is no ground and a key detect problem) if both are okay check the red wire same relay for 12vdc and then the yellow wire (the red is the supply and the yellow goes to the solenoid on the starter. If no 12vdc on yellow wire look to solenoid and starter. What I did was momentary push button to jump out the switch on the transmission until i have time to replace but be very careful as this can be dangerous. This is probably clear as mud if any question email. Hope it helps. All test must be done with key in crank position.

[duramax2002]

In my pervious post i said if no 12vdc on yellow wire and it should have said if there is 12vdc on the yellow wire then look to the starter and solenoid. Sorry