Saab 9-5 Check Engine Light

[sploosh]

1998 Saab 9-5 2.3 SE LPT with LPG conversion.

The check engine light came on about 6 months ago and I took it in to my local independent Saab place to check it out.

£150 of diagnostics later and there is an intermittent "long term trim" fault which goes away when the EMS is reset (or fuse pulled) and comes back every few hundred miles or so.

The car is a keeper so I'll live with the fault if I have to as it doesn't really affect drivability - but I'd like to know what is wrong and have a go at sorting it myself if possible - any ideas?

Bit of extra info:

Gas has been serviced and put on the diagnostics - no issues

I had to change the breather hose a while back as it had perished (around the time the light first came on so I am a little suspicious)

Every couple of months I have to clean the gunk out of the throttle body as the car can stall - this seems to fix it

The car doesn't always idle consistently

[i want an aero]

they don't like lpg, i would suggest you try bagnall saab in birmingham. the cheapest indie for miles, without the code to help you

[sploosh]

I had an initial code read done:

TRIONIC = p171 long term fuel trim
multiplicative max value air/fuel too lean

I then paid for a full fault trace which came back with no faults found (after they'd reset the original code)


The specialist that fitted the LPG reguarly has Saabs in stock and reckons they take the conversion well as long as high pressure components are used.

He showed me the performance curves for petrol and LPG on my car and they're identical and right for the car.

Is any of this associated with the "gunking" that I keep reading about on here?

[aeropilot]

sploosh said:

Every couple of months I have to clean the gunk out of the throttle body as the car can stall - this seems to fix it

Something's seriously wrong if you have to do that so often....

And as has been said, Saab's Trionic 7 engined cars are very sensitive to LPG setups.

[K321]

i agree with Bagnall Saab. they are by far best garage i been to . Ray is brilliant, cheap, cheery and will be able to sort out the car

[Aero_saab]

Common problem with lpg running T7's it has to be perfect or you get that code, you will also find the lpg will cause vavle seat recession unless you use an upper cylinder lube such as flash lube.

[sploosh]

Car is due a service in a couple of k's anyway so I'll take it in early to Bagnall's.

Fingers crossed

Cheers

[kprm77]

My old 9-5 started coming up with the CEL once it had been converted to LPG. Can't remember what it was but I'm sure it was the LPG conversion. Mine was a Landi Renzo mulit-point system. Got shot of the car as loads of problems started to manifest themselves after the conversion

[rscott]

If it's a 1998 model, won't it be T5, not T7?

[aeropilot]

rscott said:

If it's a 1998 model, won't it be T5, not T7?

No.....all petrol engined 9-5's are T7.