[Pedro(gone fishin')]

9000 cse lpt 1993 97500 miles. Cutting out intermittently at low speed (usually coming to a halt) Engine management light comes on as cuts out. Vehicle will restart immediately but with engine light on and attemting to open throttle causes engine to cut out. Leave for approx 10 mins and will then restart and run ok without engine light. Any ideas would be gratefully received

 

[billj]

Welcome to Saabscene, Pedro.
If you switch the ignition on and leave ti on without starting the engine, does the light start flashing after 10 seconds or so? If so, the number of flashes represents a code (or codes) indicating the area(s) that the engine management system is unhappy with.

I listed the flash codes in this thread.

Once we know what it's complaining about, we'll have somewhere to start looking.

 

[Pedro(gone fishin')]

Bill - Thanks for the welcome and the info. I've checked the previous thread re engine light codes and the light comes on when turning on the ignition. Without starting the engine it remains on for 3-4 seconds then goes out. I have left it for in excess of a minute but it has not started to flash. Does this indicate no fault related to the codes? I'm not getting any misfire and the car is running fine otherwise? Any other suggestions would be appreciated! The car is not proud as to where it cuts out and it is becoming potentially dangerous!

 

[johncc]

Bill, isn't it only Trionic that show the codes like that? I think the L-jet have to have a jumper or link set to do this.

Just to verify Pedro, if you re-start the engine after the stall, the check engine light stays on, right?

 

[CarlyKeith]

Pedro welcome,
Happened to me on my '92 CS. It was the lambada sensor on the 'cat sooting up. it was cleaned at the garage and all OK. was recommended to me to give the car a good blast through the gears now and then (if I did a lot of short journeys, which I do ) to burn the soot off.
HTH

 

[adrian]

Bill, isn't it only Trionic that show the codes like that? I think the L-jet have to have a jumper or link set to do this[/b]

Yep the LH2.4 needs a jumper wire to pull codes, I dont think the LH2.2 will give fault codes without the right equipement. Trionic flashes the codes with the ignition left switched on. However, I'm not sure if a 1993 lpt is trionic or not

 

[mark e]

Early 93's are likely to still be LH2.4 as they will have been the last off the line in 92. Later 93's are indeed Trionic. The quick way to tell is that if it's an LH it will have an mass meter. If it's Trinoic it will have a MAP sensor mounted on the RH side of the engine bulkhead.

 

[billj]

Originally posted by Adrian:
[qb]

However, I'm not sure if a 1993 lpt is trionic or not[/qb]

I thought all 9000 Turbos from '93 on were Trionic, but there are both Trionic and LH modules listed for the B202 turbo engines in '93, so I don't know.

Good point, Mark. The AMM/MAP will tell.

Anyway, in the absence of fault codes, we'll just have to investigate the symptoms. Stalling while coming to a halt is often a symptom of a knackered turbo bypass valve (dump valve). However, I would have thought it should restart immediately if this were the problem.

How do the plugs look? If they are very dark, perhaps there's a fault with the AMM (assuming you have one) or lambda sensor, causing rich running. I would think it would need to be very rich to cause it not to start.

Perhaps a DI cassette fault, although I'd expect to see other problems under load before you get idling/starting problems.

 

[mark e]

Hmm... I jus wonder- stalling whilst coming to a halt then not starting again sounds almost like the emmissions control playing up. IIRC on overrun, the ECU quits supplying fuel until the revs drop to about 1500 and then cuts in again. It may perhaps be a problem with the throttle position sensor.

When it doesn't start, have you tried pumping the throttle?

 

[Pedro(gone fishin')]

Many thanks to everyone for their input. To try and clarify some points the car is 1993 but pre air-bag and pre-balancer shaft. Does this help at all to define whether the codes should flash? Not sure what I'm looking for re AMM/MAP After the vehicle cuts out it will immediately re-start and upon restarting the management light stays on. If I then touch the throttle the engine immediately dies. The vehicle had a new DI cassette at approx 60000 miles and another at approx 80000 miles. Also had a new lambda sensor at approx 70000 miles. Also was mot'd 6 weeks ago when the readings were ok. No misfiring (which I got prior to failure of the first DI cassette but not the second which failed completely in the middle lane of the M67). After approx 10 minutes (just time to call the AA) the vehicle starts again and the management light goes out and the car runs fine. Cancel the AA. Now I just wait. I have given the idle control valve a good dousing in wd40. I have an aversion to main dealers. Does any of the above help more closely to define the cause of the problem? Thanks again.

 

[billj]

The MAP sensor looks like this.

Don't worry about the thing to the right of it, that's nothing to do with Trionic (it's for the braking system on late model autos).

If you have a MAP sensor, it's Trionic. If you haven't, it's got separate LH fuel injection.