bravo idling

[Anonymous]

i have a 1998 1.6 bravo. when the engine warms up the revs jump between 600 and 1000rpm on idle it does this around 4 times then the idle stabilises. i have tryed the following things with no change 1, clened throttle body with carb cleaner 2, reset ecu 3, changed spark plugs as getting desperate for ideas! what i have recently found is that if i disconnect a blue hose that goes from fuel vapour cannister to inlet manifold near map sensor when i rev the engine when it idles then the fault is not present! this hose has no obstructions in it either. is it worth me replacing the fuel vapour cannister? any help apprieciated

 

[Tom]

Thats normal.

 

[Anonymous]

my concern is that the car stalls on occasions when this happens. also when i fist bought the car it didnt do it

 

[Tom]

Did you clean the idle valve?

 

[Anonymous]

to be honest i cant seem to locate an idle valve on my management system . the throttle body only has two round sensors on it and according to my haynes manual the idle is controlled via on of these sensors which cant be removed from throttle body but when i cleaned the throttle body this sensor would have got a blasting of carb cleaner

 

[Tom]

You got a Mk2 engine? (plastic top cover)

Carb cleaner does notalot useful.

 

[Anonymous]

yeah its a plastic inlet manifold is petrol a better clener tom?

 

[Tom]

Your best bet is to take the throttle body off and clean it. You've gotta be careful not to get cleaner in the MAP sensor.

WD40 actually works quite well, use the straw to squirt it right into the idle valve holes.

 

[Anonymous]

thanks tom i will give it a go over weekend