[alien]

I can see on the throttle body there's an allen head with a lock nut - that's clearly an idle adjustment, but is there a way to set the cold idle only?

My sierra idles low in cooler weather until its up to temp, then its bang on 1000rpm (or just under). With headlights on, on a cold morning it'll sit around 500rpm and feels like it might stall. Its always done this, and i've read of other people experiencing similar so i'm hoping there's an easy fix so i can cross it off my list of little annoyances =)

Thoughts?

[MrRocky]

Headlight idle up not connected.
Connect it to 12v power from memory
I need to do the same on my engine, unsure if you can use the aircon idle up wire also.

[alien]

ah, good call - what are the odds you got pics of the locations of said wiring?

[MrRocky]

Haha zero its all taped up inder my dash except the ac stuff bunched with the oil pressure gauge.
Check your ecu pinouts it should be on there.
Im planning to wire it to 12v switch and have it on for crawling 1st low cruise control haha.

[alien]

how many RPM does yours drop with the headlights on though?

once my engine is warm i'm pretty sure it doesnt lose RPM with headlights (i'll have to check again today).

I like the switch idea =)

[MrRocky]

Mine is too low with the headlights on prob around 500-600rpm
I dont have a tacho on this car i change gears when it hit the limiter haha nah i know what the revs are from previous cars geared the same..
Ideally i suppose it should idle around 800-900

[alien]

i tested this morning while cold and once up to temp and i must have the idle up connected, as i dont see any increase (or decrease) in RPM with headlights on once warmed up... its only while the engine is cold - headlights on i'll drop about 50rpm...

Its like the choke is coming off too early... it starts fine, idles at 900rpm for about 1-2mins then idle drops until its up to temp where it returns to 900rpm.

[MrRocky]

Sounds ok mine does the same upon startup i think the cold start is set by the ecu not sensors as such (except perhaps coolant temp)
I wouldnt worry too much if its only till operating temp. Mine normally hits that in 2-3 mins of driving.

[BlueSuzy]

Adjust the screw on the TB spring cable doova. If it revs too high when your warm..its another issue.

Could be TPS

[alien]

yeah same, its just annoying and i was hoping to find a way to resolve it =)