i have a really rough idle, it is fine for the first 30 seconds or so of startup, then idles really bad, and on the odd occasion stalls. Its as if there is a bad air leak, but ive looked and cant find one...

any ideas what it could be?

 

what rpm is it on when you first start it, does it get any better when it gets up full operating temp, have you had the co mix checked

 

Brake servo! Almost guaranteed

When you switch off you'll prob hear a fain hissing as the servo is sucking in air to return to atmospheric pressure.

 

and how do i solve this? where on it is it leaking?

 

I cant tell you that mate you'll have to have a look and see if/where its leaking from.

You could try disconnecting the vacuum pipe from the inlet and plugging the hole to see if it runs better, BUT DONT DRIVE IT like that!

You can also perform a simple servo test from within the car.

Worst case scanerio a new servo is £120+ VAT

 

servo is fine.


it seems to idle fine when cold, and sometimes when warm, but alot of the time it is very lumpy, also abit when driving at constant speed in low gears

 

sorry to hi-jack this thread but when i turn my engine off i get a hissing noise from the servo area, does this mean i have a leak somewhere and if so where should i look???

 

Classic signs of an air leak though........how have you tested the servo out of interest?

Have someone sit in the car to turn it off while you inspect for leaks, typically though they leak where the master cylinder bolts in on the front.

 

by pumping the pedal till hard with engine off then starting her to see if pedal goes down a little bit

 

The pedal will always go down unless your servo is raped beyond belief though.......you need to see if it retains the vacuum without the engine running.