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keeps threatening to stall
Posted: Wed Feb 01, 2012 6:21 pm
by Cloggy Saint
My 320 has developed an annoying problem. Whenever I slow to a standstill and then take it out of gear the revs drop to about 350-400 before picking up to the normal level and idling nicely. I suppose cleaning the ICV would be a good starting point but then what?
Re: keeps threatening to stall
Posted: Wed Feb 01, 2012 6:28 pm
by mrLEE30
Airleaks in the inlet pipes.
Re: keeps threatening to stall
Posted: Wed Feb 01, 2012 6:29 pm
by hongkongfuey
check for air leaks, air filter dirty? serviced? afm set up properly?
Re: keeps threatening to stall
Posted: Wed Feb 01, 2012 6:32 pm
by Cloggy Saint
Regularly serviced and afm should be good. I'll check for air leaks. Cheers.
Re: keeps threatening to stall
Posted: Wed Feb 01, 2012 6:58 pm
by mrLEE30
Good way is to spray carb cleaner on the inlet side with the engine running, any variation in engine speed while spraying is your airleak. Wipe it off after as the cleaner can eat away plastic.
Re: keeps threatening to stall
Posted: Thu Feb 02, 2012 4:36 pm
by clipper
Mine does this to a very slight extent also. All of my inlet pipes have been off (and inspected) and all gaskets changed when I did the head, and I have since searched repeatedly for air leaks by various methods (including the carb cleaner spray) and never found any.
The AFM has been set by a reputable garagae to 1% CO at idle, but does this mean that my AFM is possibly faulty?
It has been adjusted to swipe on new, clean parts of the contact tracks but I guess that's only really borrowing time....
I hate buying parts just to try them out, but I too would like to get rid of this niggle.
Re: keeps threatening to stall
Posted: Thu Feb 02, 2012 4:50 pm
by Touring_IOM
Mine has also started doing it today; also managed to stall once.
Replaced pipes
Meticulously cleaned intake parts
AFM set at 1%
Replaced intake manifold gaskets
Cant think what else could be the problem, so I am going to check values on components this weekend, make sure they are all in line.
Re: keeps threatening to stall
Posted: Thu Feb 02, 2012 5:25 pm
by clipper
Learning mechanics as I went (rather than from a book or course) it amazed me the huge number of places that an intake leak can occur other than the intake tubes.
Maybe it would be useful to list the tubes / hoses / joins / gaskets that could cause these types of issues.
I'll try to make a decent start working from the AFM towards the motor (thinking of an M20 here):
AFM to throttle body bellow tube and connections at both ends.
Connections to Idle Control Valve including metal elbow into throttle body.
Brake servo pipes and connections at both ends.
Blanking grommet on underside of throttle body.
Throttle body to manifold gasket.
Manifold to head gaskets.
Gasket between manifold and FPR vacuum pipe take off.
FPR vacuum pipe.
Cam cover gasket and half moon rocker shaft plugs.
Oil filler cap seal.
Dip stick seal.
Crank case to manifold breather tube o rings.
Have I missed anything?