Idle RPM question

[FCD]

My Escort's owner's manual suggests the idle speed should be set at between 850-950 rpm.

Yesterday i cleaned my throttle body, it was gunked up with carbon, when i started it up for the first time after clesning it, it started idling at 1200rpm! i suppose the throttle body was so coked up with carbon that it was just really choked up, this engine being an Xr3i has the Bosch K-Jetronic CIS mechanical injection system, nothing electronic.

I adjusted the idle screw until i felt the engine ran best and not excessively high, when i went inside the car i was surprised it was idling at 1000rpm still, i thought i had set it at 900 or 950.
Would i do any harm setting it at 1000rpm? it just seems to run really nice and smooth at 1000rpm and it seems to have better throttle response from idle at 1000rpm compared to the 850 or 900 it was at before.
Bosch K-Jetronic by Argentum Enim in Sempiternum, en Flickr

 

[CharBaby]

I would say that you are fine with 1000 rpm idle.
As the engine ages, it may need a bit of a tweak. I have done this numerous times in the past when I could in fact adjust the idle. Keep it where it feel correct to you!

 

[demarpaint]

It should be OK, some might say it's a bit harder on the clutch if it's a stick. That would depend on how you drive it.

 

[FCD]

It is a manual yes.

 

[Cujet]

I'd say adjust the idle to where you like it, and where it runs best and fits your driving conditions.

 

[mk378]

A dash tach should not be trusted to measure idle rpm accurately.

 

[Trav]

No problem I saw quite a few of those Fiesta/Escort CVH engines over the years with the idle about 1100 with no trouble, when you cant get the idle any lower the auxiliary air valve is not closing fully or needs a metering head gasket and seal kit.

 

[FCD]

Originally Posted By: Trav
No problem I saw quite a few of those Fiesta/Escort CVH engines over the years with the idle about 1100 with no trouble, when you cant get the idle any lower the auxiliary air valve is not closing fully or needs a metering head gasket and seal kit.

Yes, probably the auxiliary air valve, it slightly bogs down after you give it a rev and it returns to idle speed, with the idle set at 1000rpm it doesn't bog down.
Otherwise it runs very well, for the 3 months i have had it it has been totally reliable.

 

[artificialist]

Does this idle air control valve have any connection to the cooling system? Failure to lower idle speed could indicate that the coolant temp sensor is not reading accurately.

Also, check for vacuum leaks and for a stuck PCV valve.