Saab 93 sport idling

[norman93]

I have a problem with idling from cold and when warm on my 2006 [56 plated] 1.9tid sport. I'm told its a 2007 model?!/!
This problem is not always present, but in this cold weather lately it has been a pig to get the car moving from cold. It is definately misfiring, struggles along for a while and then all of a sudden full power is available. However, when I stop again, it goes all lumpy on me. When its warmed up, the loss of power is not so noticeable, but the lumpiness is still there.
My local garage have been unable to find a solution and last year, upon advice from other SAAB owners I know, changed the EGR valve. This made a difference and was fine for a few months and then back comes the lumpy idling. At the last service, the fuel filter was changed and this made a difference as well, but after a long run [see next paragrah] it became all lumpy again.
I use a mixture of fuel varying from supermarkets to reputable branded names, without any noticeable difference but it was Shell fuel that performed the worst with the idling issue. I regularly use diesel cleaner and I do not predomonantly use the car for short journeys.However, I have noticed that when I have been on a long run [over 50 miles continual driving on motorway for example] and then have stop, again it idles poorly. Next time I stop, its fine or its not - totally unpredictable!!!
I recently had to have a new ignition module fitted and while it was there the SAAB mechanic reckoned that the poor idling might be the injectors need changing. The service manager reckoned it was the idling relays[?] - never heard of this one. But neither was certain, other than it was a relatively common problem on these engines.
Fuel consumption is good and I haven't noticed any increase.
Any suggestions [apart from get rid of the car!] would be most welcome.
Thanks

[Gouldy]

it may not be your problem but it will eliminate it, have you cleaned the boost sensor? I cleaned mine the other night and it only takes 2 mins, there is a how to here

http://www.astraownersnetwork.co.uk/showthread.php?88535-Astra-H-1-9-CDTi-HOW-TO-Clean-the-Boost-Pressure-Sensor&

also have you tried unplugged the AFM when on idle? see if it stalls or alters at all.

how many miles have you done in the car in the last year? the EGR could be clogged up again , check all the breather pipes etc are ok too as a collapsed/split one can really mess with how engines run

[norman93]

Really useful response - thanks very much and I'll certainly try the 'easy' jobs first - boost sensor cleaning and check the breather tubes.
I think I'll do one thing at a time to see what makes the most difference. Hopefully, the solution will be as above.
I have covered about 12000 miles since the EGR was replaced - mainly on longish journeys
I'll keep you posted....

[norman93]

Well well well - what a mess it was. It was actually more clogged than the one on the web link. so its now clean, well spotless actually, and engine ran fine after this, although nit was warm at the time. The test will be in the morning on a cold start.
After clening this sensor, I then took off the AFM wiring connection when it was idling.... it made no difference. Is this significant?

[Gouldy]

my boost sensor was olso worse than the one pictured, with regards to the AFM i know that on N/A engines it should normally stall etc, I will unplug mine at lunch and see if it stalls etc,

it may pay to clean out the throttle body as well as these can get gunked up with the rubbish EGR valves, shame they cant just be removed on all cars bloody things!

[norman93]

Cold starts this week and rubbish idling again. Haven't had time to look at the throttle just yet - may give that a go this weekend.

Any joy with the AFM unplugging - I would like to know what is meant to happen

Cheers

[Gouldy]

will have a look tonight just before i drive home and tell you what happens

[Gouldy]

all that happened on mine when i unplugged it , is that the engine light came on . no difference on idle,

does the idle hunts or is it stuttering

[norman93]

Solved it!

Went to a realtively local Bosch specialist injector garage and they plugged in a portable computer. They found that it was no4 cylinder not fuelling correctly on idling, but OK at other times.

So they will be 'fixing' it next week .......watch this space!

[jay140285]

Excellent news, at least you have got a result to fix.