Vauxhall Owners Forum banner

C20XE erratic idle

1K views 3 replies 2 participants last post by  grebo 
#1 ·
First time using any forum, anywhere, ever, hope it works...

I have a 1990 astra gte 16v (red top) and when I dip the clutch when changing down for instance the revs drop right out and occasionally it stalls, if it doesnt stall the revs come right back up again (1500+). and sometimes when its idling it is constantly going up and down (500 - 1500), I have done all the usual stuff (plugs, dist' cap, air filter etc) and i would rather stick my head in a blender than take it to vauxhall. Please help me somebody.....
 
#2 ·
grebo said:
First time using any forum, anywhere, ever, hope it works...
It worked ;) Welcome to Mig :)

Check the rubber hose that goes from the airflow metre to the SFi box. Make sure there aren't any cracks in it that could be letting air in. If that's intact, have a go at cleaning the idle control valve out. It sits underneath the inlet manifold - two hoses jubilee clipped to it and one electrical connection. Take it off and spray carb cleaner into it, connect a battery to it to make sure it's opening/closing properly. Relube it with some 3 in 1 or something similar after cleaning and refit. The see what happens :)
 
#3 ·
have done that (twice) now, it seems better now but its so bl**dy intermittent that I wont be able to tell for a few days. I will keep you posted, thanks for the reply. someone else mentioned to me they had the same problem and were going to change their crank sensor on the left hand side of the block, if that didnt work they said they were going to try the coolant temp sensor and knock sensor. thanks again.

Andy
 
#4 ·
follow up -

ended up doing the following:

new icv
new crank angle (rpm) sensor
changed tps
changed coil (leads plugs etc)
removed and cleaned throttle body
removed and cleaned acc cable mech
removed and cleaned vacuum pipes
new fuel filter
cleaned distributor

and did a few other things that I cant remember now.

It turns out that the gasket between the throttle body and the inlet manifold was too thin (not damaged, just thin) so no matter how tight you did up the bolts a proper seal wasnt bein made and air was getting in and messing up the mixture which resulted in the idle going up and down all the damn time. now its sweet as a nut.
alls well that ends well. (almost gave me a nervous breakdown in the process mind you)

Andy
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top