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Discussion Starter · #1 ·
This is a mystery to me but I hope not to one of you has been through it or knows the systems better than I. The problem: Intermittent No-Start while Cranking Normally.

Without warning and without pattern (that I've noticed) the 2002 9-5 will crank but not start. Normally it starts within 1-3 seconds but ocassionally fails to start after 10 seconds of cranking. When it fails there is no attempt to "catch" (as if it had too much fuel). It is as if it has no spark or no fuel. Never at home, the cure has been is to wait 3 minutes and try again. It starts on the 2nd, 3rd, 4th or 5th attempt, waiting 3 minutes between each attempt. Never has if failed at a place or for a period where I could test for fuel or spark at the cyclinder.

The 9-5 has 125,000 miles and received new plugs and fuel filter at 120,000 inspection/maintenance. At about 110,000 I removed the alarm and did not replace it. This did not have any effect on starting.

I have reviewed the other posts but did not find any exactly on point. I am leaning toward fuel pump or check valve.

Any ideas?
 

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Do you see the tach jump when it turns over?

If not,

Crank Position Sensor.
 

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Chances are a crank sensor will not cool off that quick to restart. I realized you said you didn't have a chance to really diagnose it. I might look at the fuel pressure regulater. It could be leaking causing no fuel pressure when you start it and a flooded condition at the same time.
 

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Discussion Starter · #5 ·
Reply to BurnsSide42

What is the fuel pressure while it cranks?

Does it act up when it's hot/been driven prior?

SOUNDS like it could be the crank sensor - but could also be a failing fuel pump too.
Thanks for your help.
I has not failed to start after cooling to the ambient temperture. We are in Texas and it is July so "cooled off" is 100F. For example it has not failed at home when embarking on a trip. However, it has not failed immediately after arriving home from a 20 minute trip where it had failed just 30 minutes prior. It has not failed after 30 minutes rest at home from a 30 minute trip.

What does a crank sensor do? Where is it?
 

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Discussion Starter · #6 ·
Chances are a crank sensor will not cool off that quick to restart. I realized you said you didn't have a chance to really diagnose it. I might look at the fuel pressure regulater. It could be leaking causing no fuel pressure when you start it and a flooded condition at the same time.
Thanks for your help.

I am not familar with the crank sensor. How can I test it?
 

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Crank position sensor (CPS) is mounted in the front side of the block, right behind the exhaust. Easily identified by the silver heat shield. Only 1 screw holds it in, but it's a SOB to remove because it's a t30 (torx) with limited space. Best test (especially with an intermittent problem) is to throw yours away and put in a new one. Common problem on these cars, so it's nice to know you have a new one in place. I'm leaning more towards fuel pump in your case, your mileage is right in the range where they start failing. Moonracer's right, usually it takes longer for the CPS to cool off.
 

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Discussion Starter · #9 ·
Update on Intermittent No-Start; Strong Crank 2002 12K

This is a mystery to me but I hope not to one of you has been through it or knows the systems better than I. The problem: Intermittent No-Start while Cranking Normally.

Without warning and without pattern (that I've noticed) the 2002 9-5 will crank but not start. Normally it starts within 1-3 seconds but ocassionally fails to start after 10 seconds of cranking. When it fails there is no attempt to "catch" (as if it had too much fuel). It is as if it has no spark or no fuel. Never at home, the cure has been is to wait 3 minutes and try again. It starts on the 2nd, 3rd, 4th or 5th attempt, waiting 3 minutes between each attempt. Never has if failed at a place or for a period where I could test for fuel or spark at the cyclinder.

The 9-5 has 125,000 miles and received new plugs and fuel filter at 120,000 inspection/maintenance. At about 110,000 I removed the alarm and did not replace it. This did not have any effect on starting.

I have reviewed the other posts but did not find any exactly on point. I am leaning toward fuel pump or check valve.

Any ideas?
After analyzing your advice/opinions/experience I took what I hope was a precautionary action. I replaced the crankshaft position sensor. I ordered one, paid for overnight delivery and installed it this afternoon.

Now, I will use the car normally and see what happens.

I'll post another update when I have some results.

Thanks
 

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Discussion Starter · #10 ·
Success (Probably)

As reported, I installed a new crankshaft position sensor. There has been no incidents: no intermittent no-starts since it was installed.

Only four days have passed but my confidence grows daily.

I appreciate this forum and the accumulated knowledge and experience that resides here ready to help. My own experience and most of my knowledge is from decades ago (carburetors and distributors were on every engine) so my contribution must be in other ways.

I will donate $25 today.

Thanks
 

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Wow, this is exactly what happened to me today. I was about to make my own thread.

My question to the people who commented about the problem is this: I was driving along and the car (2001 9-5 Aero) just stopped and would not restart. The tach does not jump when cranking, but when it stopped the tcs off light came on, however I could not accelerate at all.

Right before the tow truck came I was able to restart the car, annoying...

Does this sound like a CPS too?

 

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ya if your tach doesn't bounce you need a CPS and generally when the car cools down they'll start up, if it does bounce you'll need a fuel pump (which are back ordered), and in-between there trying a spare DI haha
 

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I had this same issue but the tach bounced a little but the car would not start turned out it was a broken fuel pump i installed a walbro 255 lph and she ran perfect. ironically now the problem still is there once in a while there is a long crank no start but now the needle dose not bounce so far this is always after i have driven, sometimes it starts right away even after a drive but after it sits for an hour it has a hard time starting. going to order a cps soon
 

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CPS, cheap DIY fix.

Is it an auto (Neutral Safety Switch) and we just fought similar in a 99 9-3, turned out to be starter and/or wiring from battery/rusted connections. (This was after newer fuel pump, NSS bypass, CPS and then a new starter.

I had t his same issue but the tach bounced a little but the car would not start turned out it was a broken fuel pump i installed a walbro 255 lph and she ran perfect. ironically now the problem still is there once in a while there is a long crank no start but now the needle dose not bounce so far this is always after i have driven, sometimes it starts right away even after a drive but after it sits for an hour it has a hard time starting. going to order a cps soon
 

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As weird as it was my fuel pump and CPS died days apart from eachother the pump did not even prime after i took it out it also had a broken part in it when i shook it around, i changed the CPS a few days later and solved the other problems. do not try from the top its a PITA bottom is way easier with a very small wrench and a Trox 30
 
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