Fast idle

[Madrat]

Hi everyone, just replaced sons 1997 1.0 micra vibe with 2000 1.3 micra inspiration. On the drive home (70 miles) everything was OK apart from air con not working. Put some red X in tank and poured some down throttle body to give injectors a clean but now it seams to be idling way to fast, 1200rpm, could this be down to the red X? I think the throttle body is OK, plenty of power, smooth no staling, old micra had to have new throttle body so I know what that felt like. I have turned idle speed down all the way and its now at about 650rpm but when I turn the steering now I dont hear the pressure switch kicking in to raise the revs? Could the fast idle switch be at fault? is there a way to test it?

 

[pollyp]

Check that the idle control valve is clean n ain't sticking before adjusting speed.

 

[Madrat]

OK, are these available to buy? and what about the wax stat?

 

[frank]

the maf inside the throttle body is a fragile hotwire sensor madrat, and any red x poured onto it will burn off and leave a residue
is it a 2000 coilpack model ?

 

[Madrat]

No, the older type

 

[frank]

the idle control valve is on the front then, controlled by the ecu
the idle adjust screw is just an adjustable air leak, so you adjust that in order for the i/c/v to operate from fully closed to fully open
the waxstat is at the back of the t/b, and this holds the throttle slightly open when the coolant is cold

 

[pollyp]

if ur TB is a preface waxstat operated version then this guide may help

https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256

 

[Madrat]

Seams strange that it was OK till I poured in the redX.... Might just get new TB at least then I know its not going to go any time soon.

 

[Madrat]

OK might be sorted, topped up with petrol to dilute red X in the tank and gave TB a good dose of carb cleaner, idle is back to normal and power steering switch is also kicking in. I'm going to get emissions checked are I think fuel consumption is a bit high, but as this is a new car that could be anything. Can I assume that if emissions are OK and the fact that there is no stalling, jumping, erratic idle and it has power through the rev range etc that the TB is fine?

 

[pollyp]

if it's drinking fuel, check ur O2 sensors working fast enough and brakes not binding n tyres inflated & aligned straight

 

[Madrat]

Thats why I'm getting the emissions checked, booked in next week. Just want to confirm that if they are OK then the TB is OK.