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Discussion Starter #1
ARRGH!!!! Tonight I was driving along, and while changing lanes, she stalled..

I went to start the engine.. engine cranks powerfully, but she won't start ?!?! Even after 5 tries..!!!

Immediately I thought of the crank sensor... because when I had the crank pulley replaced, the mechanic said there was some metal filings from the old crank pulley which got stuck in the crank sensor and prevented him from starting it. He had to blow it clean with compressed air.

I guess there are other possible causes for not starting : air intake, fuel ( there is about 15-16 liters in there now and the temperature is not that cold... -6 C, so I don't suspect any ice blocking the fuel line) and spark.

Any suggestion on what order to start checking stuff, to find the cause of this problem as fast as possible ??
 

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1) fuel - if it's been cranking over and not firing then the plugs should be wet (or at least you should get a strong fuel smell if you pull a plug)

2) spark - check for spark at a plug lead -

3) power to coil - if no spark then make sure you've got 12V going to the positive terminal on the coil

4) make sure your cam(s) are rotating - if the valves aren't opening and closing then it isn't gonna fire ..

if you've got spark, compression and fuel you should have ignition -
 

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Discussion Starter #3
3) power to coil - if no spark then make sure you've got 12V going to the positive terminal on the coil

4) make sure your cam(s) are rotating - if the valves aren't opening and closing then it isn't gonna fire ..
Should the 12V be at the coil input when the key is turned to "on" but not "start" position ??

How do you make sure the cams are rotating on a 16v non-turbo 2.1L engine ??
 

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ccoleman... How do you make sure the cams are rotating on a 16v non-turbo 2.1L engine ??[/QUOTE said:
Open the dist cap and see if the rotor spins when the engine spins.

Check for spark at the main lead from the coil, to the dist, remover ht wire from center of dist. Watch for spark while engine is spinning.
 

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ccoleman said:
Should the 12V be at the coil input when the key is turned to "on" but not "start" position ??

How do you make sure the cams are rotating on a 16v non-turbo 2.1L engine ??
I believe that when the ignition key is turned on the coil should be energized - but I've been wrong before (although I can't recall being wrong on that point before!) - that used to be the easy way to hot-wire a car (pre-ignition interlocks) - jumper from the battery to the coil, then bridge the starter solenoid to crank 'er over - bingo - car's running and off you go (I figured this out after a friend lost the keys to his 65 Mustang - I wasn't stealing cars!).

Couple ways to tell if the cams are turning - one is to do a compression test - if the cams aren't turning then you won't get compression. The other is to pull the cam cover and turn over the engine. Note that it's not just important that the cams turn BUT that they're timed correctly - if somehow one or both skipped a tooth or two they may be far enough out of phase where the vehicle won't run.

Best of luck

Steve
 

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Discussion Starter #6
Thanks guys... I would like to buy you all a brewski.

I tested the ignition coil with the key on for 12V and ground at the coil input. Yes. Check!

Then I tested the rotor turning when trying to start the car. It turns.. so the camshaft is turning. Check!

Is the coil ouput sparking when held close to the frame ? Yes. Check!

So it should start then, right ?! Reattach the coil output to distributor input. Try to start car.

IT STARTS !!!??!!

Looks like she has an intermittent problem in the ignition system.

Any suggestions on how to diagnose where the flaky ignition part is ??!!?????
 

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Discussion Starter #8
Thanks.. but that page is for the starter motor.. which is fine becaue it is cranking the engine perfectly well !!

Saabsite points us to look more at the fuel system.. or the ignition system.. Any suggestions on how to find the flaky part ??
 

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ccoleman said:
Thanks.. but that page is for the starter motor.. which is fine becaue it is cranking the engine perfectly well !!

Saabsite points us to look more at the fuel system.. or the ignition system.. Any suggestions on how to find the flaky part ??
I'd toss a new fuel filter at it - and perhaps a new distributor cap and rotor as well - sometimes even Saabs need a couple hours off though!

Steve
 

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Discussion Starter #10
There is engine oil coating the outside of the distributor cap, but the inside of the cap seems clean. Maybe there actually is oil inside the cap which is interfering with the ignition... At 160k miles.. is this oil there from normal engine wear ?? Where would that oil be coming from ??
 

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Oil can get in from the seal at the bottom of the disty where it goes into the head... oil outside the cap seems pretty normal, engines tend to get coated in a greasy oily stuff after some milage, unless you mean it is getting covered in liquid oil every 1000 miles or something.
 

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Have you read the fault codes yet?

Oil in the distributor cap will not stop the N/A 2.1L engine. There is no signal to interfere with other than the HT (High Tension) volts.
I would be looking to revisit the crank sensor signal and to check it thoroughly.
I have posted this before but it would seem extremely rare, I was told some years ago at a SAAB meet that some crank sensors died after coolant from a weeping water pump had soaked in and would cause all sorts of grief.

It's hard to prove but when the crank sensor went on my car, I found evidence of coolant weeping from the back plate of the water pump and it had got on to the lead and the oil pump was damp. Not sure if it was oil or coolant on the oil pump as it was so dirty. But since I have rebuilt the back plate and resealed the hoses and replaced the sensor with a second hand one, the car still goes!

Good Luck
 

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Here is something interesting that happened to me 2 hours ago.

I was working on the car, I noticed that one of the bolts holding the 2 grounds to the head was rusty. I took it off and sanded it a bit then screwed it back in, but not tight. I turn the key later, hear a buzzing from the LH computer area. Then try again and car won't start! :eek: Oh no I've fried the computer somehow! I think. Then I tighten the bolts a little bit and car fires up and runs better than it has in the past month.

So make sure to check those grounds. :lol:
 

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900t said:
Here is something interesting that happened to me 2 hours ago.

I was working on the car, I noticed that one of the bolts holding the 2 grounds to the head was rusty. I took it off and sanded it a bit then screwed it back in, but not tight. I turn the key later, hear a buzzing from the LH computer area. Then try again and car won't start! :eek: Oh no I've fried the computer somehow! I think. Then I tighten the bolts a little bit and car fires up and runs better than it has in the past month.

So make sure to check those grounds. :lol:
yeah - grounds - those overlooked electrical connections - those neglected brothers of the positive lead .... I recall my Triumph Herald having electrical problems - funny - paint and rust just don't make solid ground surfaces - same applied to a friends alpha coupe .....

Steve
 

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Discussion Starter #15
Guys you are just great..

Oil in the distributor
looks like a possibility, because when I opened the distributor, I went and wiped the metal area of the rotor. Guess what.. there was some oil grim on it ! Next time I tried to start it, it started. Maybe it was that.

Also coolant-sludge leaking from the water pump is another possibility. Remember the car overheated (belts broke after crank pulley detached from its inner rubber section.. no more water pumping.. temperature too high.. overheated)... about 2 liters of coolant overflowed from the reservoir and possibly also leaked out of the water pump "weep hole".. can't see weep hole so I can't be too sure about that part.. but there is a light brown "powdery" dust ALL OVER the engine near the firewall.

My saab specialist says this dust came from the leaking coolant when it overheated. He says pieces of metal from the crank pulley probably got stuck in the crank sensor, causing it to stall. He blew it out of there with compressed air.

Now you're saying that a coolant leak can ALSO damage the crank sensor.

I'm also going to check the grounds as per 900t's recommendation.
 

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The grounds I am referring to, open hood stand at the driver's side, you will see the intake manifold. On the cylinder head near where it meets the valve cover, on the rear of the engine (front of the car), there are 2 bolts with wires screwed in.
 

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Discussion Starter #18
The car died again last night after only 10 minutes running about 4 km..one km of that on the highway !!!

As soon as she died, I tried wiping clean the distributor rotor, but still there was NO SPARK.

Four hours later ( time to cool off ??) she started and I drove her home. Unfortunately I missed reading your post until this morning so I didnt take any crank sensor voltage or resistance measurements while she was "resting".

LAst night I had a dream in which I was seriously considering installing a crank sensor + aperture disc on the distributor...

Making that upgrade would be easy since I have a timing light gun and so I could get it aligned really quickly then epoxy it in place. It would be just like my VW Golf's Bosch distributor, which lasts practically forever, and doesn't die from heat so often like on the SAAB.

Benefits are: much easier access for servicing / testing, totally electrically equivalent to a sensor on the crank shaft, and the sensor remains SAFE from HEAT and OIL and METAL FILINGS.

Have you ever thought of installing an aperture disc / crank sensor on the distributor / cam shaft instead ??
 

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Discussion Starter #19
cdaly thanks for the crank sensor validation procedure. :)
SteveTheFolkie, 900t thanks for the tip on sanding the grounds clean.
Rodentmaster.. can I read fault codes without a special code reader ??

I am sure the flaky part is located in the ignition system, because we tried to start her while holding the center high voltage wire leading from coil to distributor, close the the frame bolt ground, and there was no spark that time.. normally there is a spark jumping to ground there, because we have tested it and we saw spark there on a previous day.

So I suppose we should validate ALL PARTS of her ignition system to find the cause of this intermittent problem.

Question... how would you validate the following:
a) ignition amplifier
b) ignition coil
c) distributor wires.
d) hall sensor on crank.. we have a proceudre from cdaly to measure voltage and resistance while cranking the engine.
 

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Some info..........

http://www.saabcentral.com/forums/showthread.php?t=60905

http://www.saabcentral.com/forums/showthread.php?t=52442

http://www.saabcentral.com/forums/showthread.php?t=55695

http://www.saabcentral.com/forums/showthread.php?t=68478&highlight=pulling+codes

The info is a bit spread out but it could all add to your solving the problem.
I think you are going to have to either get in and clean up the whole area including water pump, any suspicious water hoses, oil pump and crank seal, clean up the connectors for the sensor or even try another sensor. If not, pay someone a lot of $$$$ to get in fix it. It would appear that there is still something contaminating the signal gathering process,....... gee, if metal shavings had to blown out of there, what the heck has been done before?

If, when the car dies, does the tacho drop to zero instantly? If it does, that would be the biggest indicator that the crank pulse is dying or being lost in the loom or EZK module.

Good Luck
 
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