[the_orb]

My sierra has been doing this 4 a while now but now I've got the time to have a look...

The idle in the morning (esp in the cold) jumps from fast to slow. at startup and for about 5min it's at 2000rpm, then usually about 800 till about 15min of running then it leaps to about 3000. only in the morning and always in the same order

any suggestions...

[royce]

does it drop back from 3000 to normal?

do you have the lights, heater fan or demister on?

[the_orb]

it goes back after a while gadualy after that

i've tried endless combinations of heaters/loghts on off, no effect

[royce]

when it comes back up to 3000 check that both the water hoses on the back of the carb are hot, might be a blockage

or its an airleak or something

[the_orb]

all, good...

vacuum lines were checked last week by a pro, and i remember the water hoses 2 b hot this morn when i shecked them.

my m8's 4runner said he had the same prob, and it was electrical, but i didnt know if sierra carby's had an electrical component...

[royce]

the only electrical part on a sierra carb is the fuel solenoid on the back, no power the engine sould die and some have an idle up solenoid on the front that you could unplug to see what happens

there is also a vacuum idle up on the front, if you follow the vacuum hose down onto the manifold beside the thermostat there is a olenoid you can try unplugging too

and the hoses can look good but of somebody has put em all on wrong before (very common) they can do funny things like this

[the_orb]

thanks for that ill giv it a try in the morning

[the_orb]

didnt fix it but a new carby is (hopefully) on the way!!!

[ZukChiK]

So its all fixed now orb? Did you end up getting the carby from here?!

[the_orb]

nah the guy said when I rang it wasnt working...

But I found one for the same price in sydney, got it put on today, thanks for your help, at least your wreckers were a bit more helpful than the one's in ACT

[ZukChiK]

Ah ... they must have pulled it off after I saw them last. At that stage they probably didn't know! Good they were honest about it anyway. Hope all is well with your zook now!!