[SaabMystique]

Hey, my 2003 9-5 starts fine in the morning. It developed a hot start problem a couple of months ago. Before you send me to the CPS store, listen to this. Applying the scientific method, I've found that there is a twist. If I drive less than 30 minutes, no problem. At 30 minutes or more, she restarts zippy-quick for an hour. At about 60 minutes after turning off she cranks like crazy but does not start. Wait 3 hours from the initial turn off and she starts right up! I tried restarting a few times during that initial period before the 1 hour deadline and it does not help. I can stop for gas - fine. Quick visit to the store - fine. Spend an hour in the store and wham, no start for two more hours. Still think it's the CPS? Anyone else experience this? Could it be the computer? Temp sensor seems unlikely. I've studied the forums - didn't find one like this...

Mostly it works out, I drive to work, park all day, drive home. I can even drive to lunch and back to work. I just worry that she's trying to tell me something - Something terrible.

 

[riccster]

I don't think it's your CPS. Sounds more like your neutral safety switch, where the car won't start when the engine is hot. Some folks pour a bottle of water on it to cool it off as a quick fix. Search the forum for neutral safety switch (sometimes called a gear selector switch). The part is about $250. Some have rebuilt their unit with success.

 

[SaabMystique]

Thanks, Riccster. That looks easy enough to test. I see a cool method from Coliphage on post number 100345. If it is the source of the issue I can replace.
I get confused as to which problems allow the car to crank and which shut down the starter completely. Answer is apparently different for manual vs. auto transmissions. (Mine is auto) I'll try the NSS bypass and report back in a couple of days. (fingers crossed)

 

[Jssaab]

Intermittent hot no start, no matter how much time , is usually CPS.

 

[africansky]

Another vote for CPS.

 

[mecgmecg]

And another vote for CPS.

 

[Gidner]

My understanding of the CPS problems is that it either works or it does not. Is that not true?

 

[SaabMystique]

I found this:

NSS problems result in a No Crank situation that "sometimes" can be defeated by rowing the gear selector through all the gears.

CPS problems result in Crank but No Start, typically on hot restarts only, but no CEL.

Failed fuel pump also results in Crank but No Start, regardless of engine temperature.

If you can hear the fuel pump running when you initially turn the key, the problem is the CPS. If the fuel pump does not run when you initially turn the key the fuel pump has failed.​

 

[8pack]

Crank no start when hot CPS
No crank when hot NSS

If it is cranking over it is not your NSS. The point of the switch is to prevent the car from bumping forward when in gear, so it prevents the car from cranking. When it fails from heat it cuts out and prevents cranking...

 

[Jssaab]

My understanding of the CPS problems is that it either works or it does not. Is that not true?

No, it's intermittent no start. Will not always start when hot bit sometime
Imes does but will usually always start cold. You're issue CPS.

 

[riccster]

I changed my CPS when I had problems where the engine intermittently felt like it was missing or like it was going to stall. A new CPS definitely solved that. I didn't experience any hot start problems. That's why I suggested the NSS. But if a bad CPS also causes hot start problems, it certainly will be a cheaper replacement than a new NSS.

 

[mecgmecg]

And the CPS in my wife's car failed suddenly, as in started and drove fine until it didn't. Sometimes you get a warning, other times you don't, which makes things interesting.....

 

[SaabMystique]

The result

Thanks everyone, the majority has nailed it. The start failed cold for the first time. The CEL appeared also. I ordered a CPS through CarQuest (came from Italy). (First I ordered a cheap eBay version that didn't fit.) A mechanic friend installed it. He checked the code first and it reported weak signal from CPS. Seems to be completely cured!

The 2003 6cyl is purring like a kitten, once again. We both feel better.

One note, she never missed - engine ran quite proper when it started, which was almost every time. The decline was extreme and sudden. I really appreciate the advice. Because of you, I was prepared. ;ol;

 

[jlthunder]

The CPS on the V6 should be replaced every 75K. Mine failed at 75K and at 155K.

This was my experience, your results may vary:cheesy: