sick of googling - what is the right idle speed

[wca]

3.5 V8 converted from EFI to Holleys with Edelbrok filter and manifold.

RPM at warm idle has gone from around 1,200 to around 1,800 since changing the oil, adding a fuel filter and having a blast along the icy/damp roads.

I am guessing the clean fuel, fresh oil and filter, and the fact is has been driven a couple of hundred miles in the last few days will have moved stuff around inside the engine and fuel system so I should adjust the idle speed. What is the right(ish) range. I am guessing between 1,000 and 1,200 but that is based on a 900cc Fiat Panda and the state the car was received.

[Alexdaredevilz]

800-900 rpm is a good idle speed on a stock/small cam

[GV]

I would set my idle to whatever sounds comfortable to the engine and to the rest of the car. Remember to let the car get its normal running temp first. Are you running a Holley carb? If so we're also talking about setting the mixture too which is a must for a good idle speed.

[keatsie]

On carbs anywhere between 900 and 1100 rpm is fine

[wca]

Yes, running a Holley and yes I know that the mix needs setting properly.

I plan to get the carbs set this week it is just that without touching the carb at all the idel has gone up from about 1,100 to about 1,800 after an oil change and fitting a fuel filter. i want to drop it to something reasonable until I can find a good tuner.

EDIT - Now sitting steady at around 900rpm

Edited by wca on Tuesday 20th December 12:59

[JMF894]

There are lots of variables as mentioned.

Mine ticks over around 1200 when warm but is quite cammy.

Jimbo

[wca]

Got it running okay at 900rpm and then went to Paul's Place near Southampton today.

He pointed out that various tubes were connected to the wrong bits and a vacuum diaphragm wasn't working. He did some quick tweaks and it is running a lot better already. Going back tomorrow or Thursday to get the broken bit fixed and a tune up sorted. Very friendly bloke, even gave my friends kid a free can of coke while we looked at the engine.

[Wedg1e]

Mine will idle smoothly down to about 650 but the oil pressure starts to get a bit low...

[adam quantrill]

The answer is - it depends.

You need enough power at the lowest tickover so the engie doesn't stall when driving the ancillaries. So if you have power steering and the lights on probably 900-950. SDi's and Rover P6's on SU carbs were commonly set up at 850 as I recall.

A good test is to stick full lights on then pull the steering from side to side while idling.

[rev-erend]

As others have said .. 800~900 is good or what ever sounds best .. but if the cold weather has suddenly made
it start reving to 1800 rpm on tickover with a Holley then you have got to suspect a cold weather idle system might be responsible.

[wca]

It was the carb set up all wrong. Whoever had it before me had connected various hoses to the wrong places and the mix and tune were all to cock. Took it to "Pauls Place" who specialise in V8s and American engines and he had it running nicely in a matter of minutes. Need to take it in for a proper tune up when the replacement vacuum diaphragm arrives.