Help needed with starting problem.

[FoeCom]

Hello, I've fenished up the manual conversion on my 91 CD turbo a few days ago. Spent yesterday and today tweaking a few things to get it running right. It's been on a few trips around my neighborhood at this point, run for a total of about an hour. Was going pretty flawlessly until today. I was taking it out for a little drive again after installing a starter button. It drove for about 2-3 minutes and just cut out after coming to a stop. Now it just turns over and doesn't make any attempt to start. It was wierd because it had been driven yesterday and this morning for about 10-15 minutes each time, with absolutely no problems at all. I've checked some of the more obvious things, all fuses OK, Quarter tank of fuel. When I pulled the spark plugs I found that they were covered in carbon, so I put new ones in. No check engine light before starting. Once I try to start it, it comes on and stays on until I stop trying. Only odd thing I remember before this started is that the idle seemed to be pulsing a little. I'm really out of ideas at this point. I've got the negative lead off the battery so that it can reset the ecu, but I wouldn't think that could fix it. Also, can gas go "stale" inside of 3 months? If anyones got any suggestions I could definately use them. Thanks in advance.

[wrighar]

I would look at the last thing you changed first ( starter button). After that, all earths and wiring that will have been interfered with douring the last 3 months.

Andrew

[tomrothwell]

Does it have an immobilizer ?

Mine is std saab and kicks in after 3mins if engine not started and car not locked.

[FoeCom]

A little update... The car is not getting spark OR fuel! I'm pretty sure something has failed, not having to do with the starter switch. The local saab mechanics have said that it is very likely the crank position sensor. Their reasoning is that the ecu wont spark without it, and that the fuel pump will not pressureize either when its in this "mode". It's almost $300, and on top of that I need a new battery. Does their reasoning sound right? I can't think of much else that could stop both the DI and the fuel pump, and it's not likely both went at the same time. (Also there both new, with less than 500 miles on either) Is there a way I can be sure it's the crank position sensor? $300 is a heck of a shot in the dark.

[sgould]

Well, if you are sure that there's nothing wrong with your modifications.....

I don't have a 9000, but I had a CPS go on my 9-5 last summer. It wasn't as terminal as yours as car still ran but cut out and would re-start.

$300 seems a lot. The one in the 9-5 is a Bosch unit. So it may be available elsewhere if the 9000 uses the same supplier. The 9-5 one cost me under £60 ($110) from Elkparts. Is the 9000 one very different?

[mark e]

UK price for a 9k CPS is circa £180...

[sgould]

£180!

[FoeCom]

The mechanic was a little shocked when he looked up the price for it, seems that it's much more expensive than the surrounding years, and I suppose even on the 9-5. I'm going to pull the old one out tomarrow and see what I can see. I suppose I'll take a multimeter to it and check if it's doing anything at all. As to my starter button, I don't see how it could be doing anything like this. It started the car no-problems 2 or 3 times before I set out for the test drive. It still does a fine job of turning the engine over. I probubly started it 10 or more times with the screwdriver method before installing the switch. Also, the 9-5 has a more intelligent computer I would think. So maybe it can improvise it's timing while the 9000 just gets confused.

[FoeCom]

Yet another update... Checked out the fuel pump with a drill battery, and it works fine. So what I'm wondering, what can activate a fuel pump cut off in the car? Only two I know of is over-boost and ignition problems. I'm going to take a wild guess and say it's not over-boost Correct me if I'm wrong but the ignition system consists of only the ECU, DI, and plugs. Is the crank position sensor the only one that could cause an ignition related problem? I'm praying something didn't happen to the ECU. $1000+ to get a new one.

Edit: I did try to test the crank position sensor itself with a multimeter and breaker bar on the crank but It didn't really tell me much. According to Haynes it's resistance is double what it's supposed to be. But from the pictures their sensor looks nothing like mine.

[kpa2004]

try crank angle sensor, the computer wont give you fuel or spark if it doesnt know its turning.

[FoeCom]

Just tested my POSITIVE battery lead (disconnected) to the top of the engine block with a multi. No resistance. So I started looking for a really bad short. The cable itself was fine, no exposed metal. Connections OK. I disconnected it from my alternator and the resistance was fine again, off the meter. The bottom bolt of the alternator is making a perfect ground to the block. My dad did knock it off the workbench when I still had the car in peices, so I'm guessing I've found my problem. I'm going to jump it with another car with the alternator disconnected tomarow and see if she runs.

[FoeCom]

Problem solved! Thanks for the help guys. Alternator is still under warranty too.