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Do modern cars have automatic chokes?

I've just purchased a 72-plate Kia Picanto GT Line S. Do modern cars still have automatic chokes? My immediate area has 30mph camera controlled restrictions and I can poodle along in 5th but on the level and with foot off the accelerator it surges to 40mph so I actually have to either brake or change down to 4th but it does seem like the car is running away. When I first set out from cold, being in 1st and especially 2nd has a similar effect. I'm old enough to relate it to when you pulled out the choke too far

I noticed that idling speed is around 950 rpm, which is higher than many cars I've owned and I wondered if that's why the engine is so eager. I didn't buy it from my local Kia dealership but called in at mine and asked one of the service chaps but he stated that 950 was about right; would you concur with that?

I of course have the turbo but going back to the 'running away', I assume the turbo doesn't kick in unless there are driver inputs on the throttle?

Asked on 11 July 2023 by OGA

Answered by David Ross
Modern cars do not have automatic chokes, as the ECU will adjust the fuelling based on a number of parameters, including engine temperature, load, throttle position and so on.

The phenomenon you are experiencing is the ECU trying to maintain the correct idling speed to prevent stalling, and because you are in fifth gear this causes the vehicle to accelerate. Although the idle speed may be high in comparison to cars you have previously owned it is not exceptional, and given this is also controlled by the ECU we see no reason why it would be incorrect.

In addition the turbocharger requires a certain engine speed to being providing significant boost, and although most small turbocharged engines are designed to deliver boost from low engine revs, we would not expect it to be providing a great deal at idle. We would suggest selecting a lower gear so that the engine is above idle to maintain lower road speeds.
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