D15B4 engine idle should go higher when dead cold?

[altong0840]

hi everyone~just wonder D15B4 engine idle should go higher when dead cold?

before my old D15B4 engine goes like 1500rpm when it dead cold and it drop down to 900rpm when it warm up~

but now my new D15B4 goes like 600rpm when it dead cold and it raise back to normal 900rpm when it warm up

will i be fix it by myself with some easy friendly guide?
anyone got the same problem??

[bboyzell]

I remeber that my old D15B would do the same
sit at 1500rpm when cold and tends to drop down to 900rpm or so after a 5 min driver.

Not sure whats going on with it starting at a lower RPM tho

[twing]

Dead cold idle should be higher than warm up idle.
Something is not right with your new engine.
Check all sensor cables are not loose.

[altong0840]

Dead cold idle should be higher than warm up idle.
Something is not right with your new engine.
Check all sensor cables are not loose.

actually it is a twin carby engine and which senior is the biggest chance to mess up my idle if there is senior? please advice~

i know normally it should higher when dead cold
and recently i replaced the aftermarket air-con idle control
will it affect? but the problem happen before i replace it~

the detail information i found that it goes 900, and then 600 rpm and stay for 5 mins, and back to 900rpm, will the information helpful?

cheez

[酸菜炖肉]

could be vaccum leak somewhere,or the idle control valve.

[altong0840]

could be vaccum leak somewhere,or the idle control valve.

all vaccum line checked but no luck....locating where is the idle control valve...but dunno where is it....can anyone please show where it locate to??cheez