Thread: erratic idle

Most after market ECUs don't use an airflow meter, they use MAP sense (manifold apsolute pressure)and or TPS only so you just chuck it away. In fact v12 jag engines work this way as well.

I'm having the same problem, one thing i am about to try is to change the fuel filter,

tried that... you'll probably find it is either the air flow meter or the steeper motor, in my case it is neither !! Still haven't worked it out, going to go though and replace all the hoses next.

It's doing it again... new airflow meter (secondhand actually), and 4 weels later it is doing it again, what do people think about replacing the hose that goes from the plenum chamber to the AFM ? maybe it has a small pin hole, can't see one though.

Any ideas ?

8) ok do you get the mystery rich running on slowdown after highway cruising?
8) harry

yes, but it will also happen to and from work, and that is in traffic, but only once the car has warmed up... Also it doesn't always happen !!

8) its a small relief to find someone has the same disco virus,
it can be rather embarassing to have it flame out at the traffic lights just as they turn green.
yesterday i had to follow a bus down from o'reillys mountain, and with it stopping often to allow cars past, the disco began to rich up.
its almost like it drops a bank. finally it stopped and i was lucky enough to roll to a clearing.
getting going again is simple - just open the bonnet [why did the pomms put the cable on the left?] let the fuel pressure down by pressing on the valve then start it up
8) harry

It can also be caused by the throttle butterfly position it's supposed to be a certain measurement (19Thou I think) leaning towards the plenum chamber in the direction to which the throttle turns, mine was always a problem so I adjusted it down reset the base idle and have had no problem since, the other reason could be that it (the butterfly) and throttle body needs a good clean out with carby clean. One more thing the throttle shaft potentiometer could be stuffed and sending all the wrong messages to the ECU, this I have found to be a problem as well.
Regards:- Patrick M.