2.1 DJ Low Speed Hunting

[wixer]

I've got an annoying problem that seems to have got worse over the last month or so. The van's hunting on very slight throttle at crawling pace. Once it starts doing it, I can take my foot off the accelerator and it will continue and actually get worse to the stage the van's kangarooing like a good 'un. At this stage I have to dip the clutch. So driving in slow moving traffic is a right pain in the backside as I'm having to slip the clutch alot to keep things smooth.

Anyone got any ideas ?

[Aidan]

idle control circuit not functioning correctly, switch, controllers, valve...or poor injector(s) or other fuel delivery issue

[syncrosimon]

I get these symptoms every now and then, and have found the only cure a fresh tank of petrol. My high compression DJ seems very sensitive to fuel quality. Getting the exact best tune up for you engine is really important. I also think that wear in the throttle body can cause this problem, in conjunction with the setting of the throttle position switch.

The ecu needs to know the exact point at which you have taken your foot off the pedal, when it senses a closed throttle it switches to a predetermined tick over setting. The ecu getting bad information about this point is in my opinion why you can sometimes get a kangarooing effect. I have checked all parts of my system, and it is in order, the age of the fuel seems to effect the place where you get the cross over in the ecu from drive to tick over slighly out, and cause this problem.

Hope that makes sense.

Check the throttle position switch, as the throttle body wears out it will now be out of spec.
Give her a tune, and try slight changes in timing and mixture.
I found that my tick over had to be on the rich side to get a smooth interaction between drive and trailing throttle.