(T) Car accelerating by itself, 700 RPM, First Gear

Hi, I own a Fiat Stilo, a really cool car and cheap to the point I can do the maintenance and learn about the car without worrying too much, the problem is, I bought the car early February 2019 and this was not happening. So to the point, it's a 1.2 16v 80HP 3 door car, manual transmission, the maintenance is up to date, the throttle position I'll try to record it tomorrow, if you want specific values just ask please, I have MultiEcuScan and can provide to you, no stored codes, in any modules what so ever, so I can put it in first gear, accelerate on a steep road and let go the clutch and the throttle and the car goes by itself I only tried some distance, not much, but I'm sure its not some newton law.

Thanks in advance.

Edit: it happens on other gears, tried thid and it would not die.

I don't understand. You are saying that if you don't touch a gas pedal, car will accelerate? Or it would hold some speed?

Does the car idle okay?

And does the throttle work properly if you rev the engine a few revs and then release the pedal?

If the revs rise and fall immediately and then it settles back to idle promptly, then it sounds okay to me.

What you might be noticing is the "anti-stall". It's not very sophisticated but the engine can detect when it is about to stall and the ECU will give it some extra gas to keep the engine running, for example if you're going up hill with no throttle and in gear.

If you have the information panel between the dials that shows Date, Average speed etc. and you set it to "Instant Consumption" then when the anti-stall is working you can just briefly see the IC sinks like the Titanic.

Such low rpm and juddering can cause problems with your transmission and even your big end bearings (it needs smoooooth... not lumpy) so don't try to drive like this normally.


Ralf S.

It idles very well, i dont know if its the anti-stall, the revs keep low and the car can go for km without stall, i will check when i get out of work, i just think its weird

Yes.. it can feel strange, like a surge. My JTD does it too, especially in traffic. But it's easy for it to run away by itself, so you just need to control it.


Ralf S.