GQ TD42 Idle up for no apparent reason

[Kelvinator]

G'Day guys,
Just wondering if anybody has had this issue before. My 92 GQ TD42 started idling up for no apparent reason a while back. I work on the old girl all the time and change things frequently so I am unsure at which point it started doing this.

Basically what it is doing is idling up all the time, and then when it should be idling up, eg; aircon switched on, it idles down instead. Now I haven't investigated how that vacuum operated idle up works (the one with the line off the alternator up to the do-hickey near the brake booster and the line to the diesel pump) but if anybody has any info or a fix for me please let me know. I have tried the hoses around the other way as they appeared to be back to front compared to a mates td42 but that didn't change anything.

I currently have a pretty poor start battery also, is it possible its chasing voltage?

Any help would be golden, cheers in advance.

[nissannewby]

Can you see the actuator actually holding on?

You can just remove it and bump your idle up to around 800 to compensate.

[Kelvinator]

Nah it doesn't appear to be sticking, it appears to be working in reverse. Idling up when its supposed to be down, idling down when its supposed to idle up. It did work the correct way before, unsure what changed. Would much rather get it working than remove it entirely as I use the air-con quite a bit and without it its fairly noticeable.

[Kelvinator]

I had a think about what you said last night newby(it was a slow process on night-shift) and your right, it could very well be stuck open. And just loading up to bring it back down. I nearly broke my brain with that thought at the level of tiredness I had achieved.

Second question, how do you adjust your idle on those diesel pumps?

[nissannewby]

Just adjust the stop on the throttle shaft the part which the cable connects to.

[Kelvinator]

Yeah Rito, cheers Cob