SaabCentral Forums banner
1 - 20 of 37 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Well it is a Saab after all, so I guess it had to happen eventually. It is annoying as I've changed the drive belt, tensioner and both idler pulleys, spark plugs, oil filter, air filter and engine oil as a preventative measure.

Up until now the car has started first time, every time almost immediately.

Yesterday it didn't want to play. The starter cranks over strongly but nothing else happens. So far I've checked all fuses which are OK.

I'm planning to check for a spark at one of the plugs (earth to engine block) at lunch time, in order to rule out the ignition coil or ignition amplifier.

If this does give a spark I assume it will be fuel delivery related. Could this be the crankshaft position sensor?

Any advice would be very appreciated as I cannot afford to put this thing into a garage at the moment!

The car is a GM900 2.0i NA. 1996.

Also, I can report that public transport is as bad as it ever has been this morning :nono;
 

·
Registered
Joined
·
1,996 Posts
Do you hear the "whirring" sound of the fuel pump when you turn the key to the first detent? If you don't, then it's a fuel pump problem...
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #4 ·
Yes, I have reset the alarm :lol: Although I haven't ruled out the alarm itself causing this problem. Could the immobiliser become stuck on?

Update: I've tested for a spark and got nothing. The dizzy was pretty grimy so I've cleaned that up with WD40 and emery cloth. Still, no spark although it did seem to almost try to fire up this time. Now nothing again.

I can hear the buzz of the fuel pump, so I'm pretty sure it's not that.

I'm guessing the ignition coil, but they aren't cheap so I'm calling the AA out. Hopefully they can narrow it down for me!

Can't cope with too many more train journeys :eek:
 

·
Registered
Joined
·
1,568 Posts
Did you check your fuel lines? Maybe check where the lines come in and out of the fuel filter...heck check the filter. If there is no fuel being delivered then the engine will just sit there and crank for eternity.
 

·
Registered
Joined
·
21,583 Posts
Pull the plugs, if they are wet with fuel, then it could well be the coil - but check this out as well.

There are specs for the coil in Haynes, I believe...
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #8 ·
Thanks for everyones help. The AA man has diagnosed the problem as a faulty fuel pump. Cost is just over £300. So I guess add a couple of hours labour, new filter and it's going to be at least £500.

To be honest, there's no way I'm going to pay that and there's no way I can fit it my self as it is on top of the fuel tank. £500 would get me to work for 6 months on the train anyway with a season ticket!

I guess it's goodbye Saab unless someone has any bright ideas? There is voltage to the pump, earth is good and it doesn't make any noise whatsoever.

I guess it was a tad ambitious trying to run a Saab on a small budget in the first place, so my own fault ;oops:
 

·
Registered
Joined
·
21,583 Posts
So I take it that we have dry plugs then..

This for the skilled DIY
Search for the fuel pump replacement site( Munki's ?)
Cut a 3 to 5 inch hole above the fuel pump, along side the useless access plate.
Remove the pump assembly, from that, separate the old pump and install a new one from NAPA, or Vauxhall ??
The cost should be around $100...
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #10 · (Edited)
Yes, the plugs are dry and there is a strong spark.

NAPA or Vauxhall? Which vauxhall fuel pump would I have to fit?

This sounds doable, although I would be concerned about blowing myself up!

Edit: Just found a suitable pump on ebay, so if I get that for a good price I may yet be OK :)
 

·
Registered
Joined
·
1,568 Posts
PompeyPete said:
This sounds doable, although I would be concerned about blowing myself up!
Hey, if anyone should be voted most likely to blow themselves up, it would be me. i'm still here...you should be fine. :cheesy:
 

·
Registered
Joined
·
4,293 Posts
Cars with Trionic and Motronic ignition systems act a little differently, but in both cases, if the CPS (crank position sensor) fails, the ecu will not send any fuel.

Meaning, if there is no signal from the CPS to the ecu, the ecu will not send a signal to open the injectors... so, fuel circulates through the fuel rail and back to the fuel tank, BUT no fuel in the cylinder, sparkplug end dry.

AA may not know that.

IF you can really hear the fuel pump start as Pete said in his second post (I can only tell for certain on my car if I lift the rear seat and put my ear over the fuel tank while someone cranks the engine), AND if there is no fuel to the cylinder, THEN I would suspect the CPS!
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #13 ·
The AA man did say he couldn't hear the pump at all, although I swear I heard it prime when I first turned the igntion to the 'on' position.

I will double check this again today, as a CPS is only £60 and an easy replacement. If not, a spare fuel pump wouldn't hurt anyway as just about anything seems prone to sudden death syndrome on these cars :roll:

If anyone's wondering why I'm posting at 6:20am it is because I now have to get up 1hr earlier to get the train to work. Not as bad I originally feared, they even have air conditioning now (and it doenst rattle like my saab air con, lol).
 

·
Registered
Joined
·
4,293 Posts
PompeyPete said:
The AA man did say he couldn't hear the pump at all, although I swear I heard it prime when I first turned the igntion to the 'on' position.
Could be that if there is no signal from the CPS, the ecu does not turn on the pump at all (?). There was a post from Slaab4Life earlier about the pump on cars with the Motronic ignition priming. I can't confirm that, since mine has the Trionic T5 system. Perhaps you can hear it "prime" but not run. See his post in the thread below.

http://www.saabcentral.com/forums/showthread.php?t=54363

Also see post about CPS insulation cracking:

http://www.saabcentral.com/forums/showthread.php?t=58982
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #15 ·
It depends on the sequence of events that occur when starting the car.

If the ECU requires a signal from the CPS to switch the pump on in order to start the car, then it could be the CPS. If however it only uses the CPS once the car has been started, it may not be.

Can anyone comment on this? If I rip the thing out, what am I looking for? Broken wires would be obvious but if not, does anyone know the resistances I should be measuring? If so, I can not only test the CPS but also fool the ECU into thinking it has a working CPS attached, by connecting resistors to the multiplug.

I've decided I'm going to have a good go at DIY'ing this but I dont want to cut holes in my car and risk spontaneous combustion etc unless I'm sure I'm replacing the right part :confused:
 

·
Registered
Joined
·
4,293 Posts
PompeyPete said:
It depends on the sequence of events that occur when starting the car.
There has to be a signal from the CPS indicating that the engine is being cranked before the car will start.

No signal, no start.

The CPS is a Hall-effect sensor which sends out an AC signal, with a frequency proportional to rpm. After start, the signal is used differently on the turbo engines with Trionic ignition and on the engines with Motronic.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #17 ·
I've just spent the last hour trying to get the damn thing out. The Torq screw is rusted solid and won't come off. I had to remove the radiator fan just to get near it.

To be honest, it's a 10 year old car with 180,000 miles on the clock. There can't be much life left in it. There's no way I'm taking it to a garage, just isn't worth the money. Time to move on you think? I'm finding I have less and less time to keep old bangers on the road now, and I really need a reliable motor.
 

·
Registered
Joined
·
21,583 Posts
The crankshaft position sensor
Resistance is 540 ohms (p 4A-2)
and then there is a 1.0 mm clearance at the reluctor disk.
Use some quality penetrating oil and a impact tool at this nut, but the trouble is, the radiator may have to be removed...

There must be an easier way to test these devices - and there may be at the dealers - at $100 per hour...

Maybe this is for the better ??..
But only 10 years,180K miles .. .. .. good twenty years ago, NOT good,IMO, today, considering how expensive new cars are...

I wonder if this is average or not ??
Our Honda was good for 15 years,170K, and more with the third owner
The Volvo - 16 years, 240K, still good
The VW Golf Diesel - 15 years - sold for $350(very rough body), as I recall, but ran fine....
Other than the engine($1100, my labor) at 120K for the Diesel VW, little money was spend on any of these....
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #19 ·
Thanks for the info, I'll check that out tomorrow.

I agree, I do think the radiator will have to be removed as the only thing that's going to budge that torq is an air wrench or something similar. The coolant is due a change in a couple of months anyway, so good excuse to do that. The sump plug needs similar treatment as I couldn't budge that the last time I tried.

So mission for tomorrow (and the weekend) is find someone who can remove the torq for me, source a new fuel pump and potentially cut a big hole under the back seat of my car.

Oh the joys of Saab ownership :roll:
 

·
Registered
Joined
·
154 Posts
Hi mate, theres one on ebay for £20 + £9 postage Item No 4576201581 ends tomorrow at around 9am

you do have to remove the tank to replace it put they are plastic tanks so not that hard to remove if you can borrow a pair of ramps.
Lots of info in the haynes manual

PompeyPete said:
Well it is a Saab after all, so I guess it had to happen eventually. It is annoying as I've changed the drive belt, tensioner and both idler pulleys, spark plugs, oil filter, air filter and engine oil as a preventative measure.

Up until now the car has started first time, every time almost immediately.

Yesterday it didn't want to play. The starter cranks over strongly but nothing else happens. So far I've checked all fuses which are OK.

I'm planning to check for a spark at one of the plugs (earth to engine block) at lunch time, in order to rule out the ignition coil or ignition amplifier.

If this does give a spark I assume it will be fuel delivery related. Could this be the crankshaft position sensor?

Any advice would be very appreciated as I cannot afford to put this thing into a garage at the moment!

The car is a GM900 2.0i NA. 1996.

Also, I can report that public transport is as bad as it ever has been this morning :nono;
 
1 - 20 of 37 Posts
Top