Vauxhall Astra 1.8 sport 1998 - ianden
Can anyone help? 3 problems: 1.Very uneven running at steady low speed e.g. 30mph. 2. Keeps stalling when coming to stop, idle drops too far,
3. Airbag warning light, how is this reset (without going to dealer!). With respect to 2. the car has the idle control valve integrated with the throttle body.
Vauxhall Astra 1.8 sport 1998 - Ruperts Trooper
Mk3 (Astra-F) or mk4 (Astra-G)?

On Astra-G there's no separate idle control valve, it's just a stepper motor operating on the throttle body. The symptoms are classic for a gungy throttle body (note the use of technical term!). Remove the air intake ducting and give the throttle body a good clean, removing all oil, carbon, etc and finish with carb cleaner.

Airbag warning light reset can only be done on Tech2, or equivalent, diagnostic equipment so a trip to the dealer is needed.
Vauxhall Astra 1.8 sport 1998 - ianden
Thanks for the reply, it's a Mk 4.
I did try cleaning it but there is no direct access to the mechanism. It worked for a while but soon deteriorated. Any thoughts on the uneven running; EGR perhaps?
Vauxhall Astra 1.8 sport 1998 - Ruperts Trooper
The EGR can also carbon up and give similar symptoms.

It's possible to disable the EGR by adding a false gasket, made out of a beer can, with only one hole in it. This will improve the throttle response.
Vauxhall Astra 1.8 sport 1998 - ianden
Thanks Ruperts Trooper, I'll try the false gasket. I did try unplugging and I think it helped, (my son, whose car it is, wasn't quite so sure) but that leaves the engine management light lit on the dahboard so leaving it plugged still would br better.
Vauxhall Astra 1.8 sport 1998 - Ruperts Trooper
I guess a '98 has quite a lot of miles on it so normal engine wear may be allowing a lot of oil fumes to be sucked into the throttle body in which case regular cleaning, every couple of thousand miles or so, would probably help.
Vauxhall Astra 1.8 sport 1998 - elekie&a/c doctor
It is possible to buy the blanking gasket for the egr valve from Vauxhall dealer.About £3.
Vauxhall Astra 1.8 sport 1998 - Ruperts Trooper
It's cheaper to buy a can of lager/beer/pop, drink the contents and then cut the can up to make a gasket. Ordinary scissors will do.
Vauxhall Astra 1.8 sport 1998 - MerlinTec
I would also look at the breathers especially the small pipe from the engine to the inlet manifold. This pipe blocks up as it goes into the inlet manifold, I bet it's blocked there and this stops the engine from breathing correctly and will make it stall.