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Another 'erratic idle' thread
Posted: Fri Mar 05, 2010 8:42 am
by choppa7
M40 1.8
Car starts fine everytime, but once its warm driving along, when I dip the clutch at lights or roundabouts, the revs drop pretty low and its cut out a couple of times, always jumps back to life
Also, when driving along, theres like an intermittant misfire, where the car will stutter under acceleration, if I let of and accelerate again, its fine
Could this be to do with the AFM/MAF/whatever its called needing a clean, and if so, whats the best way to go about it?
I'm having a spannering day on Sunday so I'll give it a bash then
Thanks

Re: Another 'erratic idle' thread
Posted: Fri Mar 05, 2010 9:09 am
by Brianmoooore
Intermittent misfire of the type you describe is usually down to ignition components on the M40. Check out the distributor cap, rotor arm and plugs. (Note the colour of the plugs while you have them out.)
Idle problem: First things to check are the condition of the big hose between the air meter and the throttle body, and, while it's off, check that the throttle position switch is working electrically.
Re: Another 'erratic idle' thread
Posted: Fri Mar 05, 2010 9:30 am
by choppa7
Smashing, thanks for that Brian
Re: Another 'erratic idle' thread
Posted: Sat Mar 13, 2010 11:22 pm
by bmbartlett
how did u get on mate? i have exactly the same issue
Re: Another 'erratic idle' thread
Posted: Sun Mar 14, 2010 7:59 am
by djscottfree
i had a misfire on cylinder 2 turned out to be the fuel injectors sticking, put some fuel system cleaner in and thats sorted it out
Re: Another 'erratic idle' thread
Posted: Sun Mar 14, 2010 9:54 am
by Brianmoooore
djscottfree wrote:i had a misfire on cylinder 2 turned out to be the fuel injectors sticking, put some fuel system cleaner in and thats sorted it out
Get 'em out, and off to injectortune - it'll be the best £40 you've ever spent on your car.
Re: Another 'erratic idle' thread
Posted: Sun Mar 14, 2010 1:55 pm
by bmbartlett
How did you find out it was an injector sticking mate? Think il be sending my injectors off, I have the exact same issue. Would a sticking injector cause another other symptoms?
Re: Another 'erratic idle' thread
Posted: Sun Mar 14, 2010 3:16 pm
by djscottfree
bmw specialist told me this it wasnt any of the other obvious things like, dizzy cap, plugs etc, but sticking injectors cause misfires as ive experienced this. i had to put 2 lots of cleaner in, premium redex worked for me the 2nd time , fuel cleaner doesnt fix the misfire instantly well it didnt for me.
http://www.halfords.com/webapp/wcs/stor ... p&istBid=t