[Banman]

First off the victim is a 91 900S (sorta...) It has the original LH2.4.2 ecu and EZK ignition w/hall sensor on the crank. This is mated to a '92 turbo engine--together they have run very well for the last 22,000 miles giving me an average of 29mpg. Being a hybrid ain't the problem...

OK, best as I can describe it: driving along fat, dumb, and happy the engine suddenly and abruptly quits--as if turned off. NO check eng. lite comes on when this stall occurs. It happened once 2 weeks ago on the way to work (50 miles each way) ten minutes later it restarted. Last week it happened again only after restarting it (and it restarts easily WHEN it restarts) it would only go a few miles before stalling again. Naturally now that its towed back to my garage I can't find anything wrong
The check eng. codes are as follows: 12222/ 12112/ 12252 nothing that would indicate a serious problem. Fuel System test went as should--everything checked ok except the AIC didn't cycle on/off
Can someone tell me what 12414 is supposed to test--it's not listed in the Bently test cycle. The other surprise was 12415 turning my fan on and cycling my A/C clutch--this test was also not listed in the Bently...

Aside from telling me to drive the car till it stalls again and then see what's not working correctly is there anything else I can do. I'm not looking forwad to leaving the car idle in the driveway till it dies so I can try and find whats wrong but I guess I may have to--hate to waste the gas...
Anybody with a similar tale and what was replaced that fixed it?

 

[grif900]

Any loss of power before the stall? sounds kind of like a clogged cat.

 

[16saabs]

i would possibly go for the cc sensor, as that is how my first one went, just played up now and a again and then one day dead, start up later run for about 3-4 mins(tickover) then missfirelike nothing else till stall. new cc and gone, next time it went(was 2nd hand unit) it just dide and that was it,replacement just like new.
and once you have done it you know the probs for next time and get it done in half the time.max 2hrs unless you have air con belt etc

 

[Banman]

I'm not familiar with "cc sensor" ? Does it go by any other names you can think of?

I've also discovered that the wires going into the AIC were possibly shorting--that (bad saab idea) hard insulation actually rubbed a groove across all three wires of the AIC at the plug... Since these feed into the LH ecu I'm now guessing my ecu may be damaged... I'll update after testing the ecu.

 

[DanF.]

Torque is about PFT lb/ft.

 

[16saabs]

cc sensor is the " crankcase" sensor which delivers the info/ spark for the electronic box to make a spark, if they go, no spark

 

[SteveTheFolkie]

shot in the dark, perhaps, but check your coil. Over time carbon can accumulate in the oil bath in a coil - especially as a coil heats up these carbon traces can short out the coil internally, causing your engine to conk out. A few minutes later, a bit cooler, the coil works (for a shorter period of time than it did before) - if you've got a "known good" coil - swap it in.

 

[RevPhilip]

Your car sounds just like mine did a few months ago. A brief engine shudder then it just dies and re-started a few minutes later. Two weeks later it did it again, and then a week later, after that it was everytime I did more than 4 miles in the car. But would always re-start a few mins/hours later.
It turned out to be the cam sensor, which is very expensive new (about £180) I got second hand from two stroke turbo for £45, now the car runs perfectly (It just clocked over 200,00 miles in the summer)
Philip

 

[Banman]

RevPhilip and 16saabs referring to the "Hall sensor" which is located behind the crank pully on later 900's ? Is there any way to test the Hall sensor besides driving the car till it stalls and seeing if the Hall sensor is then "dead" ?

I'm thinking the shorted AIC wires damaged my ECU--got lucky today at the bone yard. An ECU from a '91 for $5. Hopefully it's in good shape. I'll replace it and the AIC wiring tomorrow and retest...

Soldered in the new wire and plug for the AIC--ran the self test for the LH ecu and now the AIC works--the "new" ecu also works smoothly. Still don't know if that's the 'cause of my woes though...

 

[MilliondollarSaab]

Same Here

My 1991 Saab 900 Has been in the shop for 3 months. I have spent over $2,000 in repairs.

The Problem is the same. My car stalls while drving. After a hour or so it will start back up drive a little bit more than stall again. Sometimes it will drive for a week w/o any problems, but the problem resurfaces again. Of course when I take it to the garage the car never fails?!?! I can't afford to keep playing the guessing game with this car. Does this stalling sound familair to anyone? Stall start Stall Start? What should I do? Ive changed the entire fuel pump, igntion coil.

Please advise.

 

[16saabs]

as said earlier by me and rev phillip, if it's the cc you cannot check it very easy it can be back to ok by the time you check it so it always reads as ok, it takes approx 2hrs to take it out and replace, as you have to undo the alt and air con pulley tension and remove belts then remove pulley wheel and then with remove two little bolts(torx head) to remove cc, then put it back, when i had mine go it was out of comission for 3 months(got another car to use and one for spares) had new wiring put in, as it did not show fault on tester,(£200) then took it to saab dealership and he said you need an new amm before we can test(retest) what else it might be(£60)found out from mechanic friend that it might be CC and it was, not saying it is, but leans towards it.
if you can get/ borrow a later distributor that has the wires on the side you can connect that to your wiring and if it runs ok it will prove the problem, with the cc type dizzy there are no electric guts in them like the others.

 

[Banman]

So far... after replacing the AIC harness and the LH ECU I now have a working AIC system. After changing the ECU I noticed that now when I start the car the alternator light immediatly goes out--I used to have to rev the engine above 1200rpm for the alternator light to go out...

Eng. check light codes now say nothings wrong except purge valve...

Electrical tests imply that the pulse amplifier (fender mounted) is out of spec. swapped it with another one and get the same incorrect voltage. Swapped the EZK and same, same. Next monday I'll pick up another amplifier at the boneyard--unlikely they're all bad the same way...
Maybe I'm not testing it right or Bentlys is wrong (typo?)
Left the car running on high idle (1200 rpm) for 45min. and no stalling occured. Not the same as running under load but that experiment will have to wait...

I'm going to replace the dizzy (since I already have one in stock) with one from a tubo (hall sensor in the dizzy) grab a turbo dizzy wiring harness and when I try driving the car if and when it stalls I can plug and play the hall sensor to see if that was what was causing the problem. I'll also leave my ohm meter and a spare EZK in the car.

Any other suggestions are most welcome.

 

[Banman]

For what it's worth...

I've driven 200 miles on my now hopefully repaired 900.

The coil was just barely out of spec--so I replaced it with a spare.

My ECU WAS damaged by the shorted AIC wires. Replacing the ECU and faulty AIC wiring is probably what was needed to fix the stalling--no knowing what voltage spikes going into the ECU did...

Happy Saabing