Mechanics

RPM GOING 3 X100 IN MORNING

1999 Honda City • 240,000 miles

My car have RPM problem when I start in a morning, its RPM going up till 4 x100 and after half an hour its going down automatically.

I have check many mechanic but problem are still not solve.

your swift response will be highly appreciated.

regards
YS
Avatar
Yasir.shaikh1
March 5, 2012.



Check the idle air control valve and clean the throttle body

Rasmataz
Mar 5, 2012.
Is the MIL indicating?

KHLow2008
Mar 5, 2012.
No. Its not indicate. Just RPM going up for 30mins in a morning.

Tiny
Yasir.shaikh1
Mar 6, 2012.
Follow Rasmataz's recommendation, check the IAC for sticking.

Ensure you have sufficient coolant in system and coolant hoses to IAC are not clogged.

Check for vacuum leakages.

After engine warms up to operating conditions, what is the idling speed?

KHLow2008
Mar 6, 2012.
IAC is jammed, if I trying to open hardly so it will break and here in Karachi, Pakistan new IAC are not available in open market.

After engine warm-up the car running normally with idling only when I start in morning or after 2 or 3 hour time its idling and RPM goes 4x1000 for half an hour or more.

Tiny
Yasir.shaikh1
Mar 15, 2012.
If you have removed the IAC from the housing, don't disassemble it.
Spray some rust penetrant into the [ports and let it soak for a while. Use a feeler and gently pry at the vale to make it open. DO NOT force as it will damage the valve. Try to slowly work the valve loose. It might take some time.

Use carb cleaner to clean what ever dirt inside the chamber and after job is done, make sure the valve moves easily with minimal force and befor installation back to throttle body, spray some rust penetrant into the chamber again to lubricate the bearings. Let it soak for a while as the 2 bearings would seize if it is not lubricated.

KHLow2008
Mar 15, 2012.