Increase RPM at idle in a traffic jam

[Achille]

Hi,
yesterday i remained blocked in a traffic jam due to a car-crash.
For 20 min the car speed was at human walking (old) speed with frequent stop and go.
The water temperature indicator remained at 3/4 (below the critical level)
This is quite common in Italy but this time
the RPM of the engine at idle increase from 900 to 2000....
This did never happened before even in off-road.
The O2 sensor is new (1 months old), K&N air filter is clean and the EFI code check do not give any issue.
What do you think: normal, other sensors close to the end, fuel filter clogged...
Thanks
Achille

[RockyF75]

Did you try 'tapping' the acclelerator. Just revving it a bit when its doing it. My old ute used to do similar, and i'd just give it a little rev and it went back to normal. Somehting was sticking, i never took much notice of it but i didnt really care about that car

[-Mick-]

my girlfriends feroza did this just recently where it would rev hard at the lights. Turned out the radiator was split badly and shooting coolant out and the engine was trying to compensate somehow for the lack of cooling.

150 to repair the radiator

[MightyMouse]

The temperature controlled idle speed valve under the throttle body has never worked that well on my Feroza - and when used hard off road the temperature and idle speed go up, but not as far as yours.....

The valve is also prone to getting oil from the crankcase breather in it and getting junk stuck in it also. Having looked at a second hand one its a miracle they work at all.

They also don't come apart so unless its an on going problem ........

[murcod]

Mine stuck once so I lubed it with some WD40 and prodded it with a screwdriver. It's been fine since then (at least two years ago!)

[Achille]

All,
Thanks for the suggestions.

Murcod,
where is located the Temperature Controlled Idle speed and how did you reached it in order to lubricate with WD40 ?
Thanks
Achille

[rockzilla]

All,
Thanks for the suggestions.

Murcod,
where is located the Temperature Controlled Idle speed and how did you reached it in order to lubricate with WD40 ?
Thanks
Achille

coolant level low?

[murcod]

You need to remove the air inlet hose off the throttle body and there you'll see an oval hole at the bottom just in front of the butterfly. The air passes through there. I actually removed the throttle body to do it and liberally sprayed WD40 into the hole at both ends and prodded the valve with a screwdriver.

Don't use silicone spray as it will stuff your Oxy sensor!

As Rockzilla mentioned it would pay to make sure that coolant is actually flowing through it (two coolant lines are on the bottom of the throttle body.)