Hello,

I bought a 1.4 natural aspiration petrol engined Bravo, made in 2008, so an early version. Altough it is not a muscle car is very convinient to drive. I have no issues with it only the idling drives me crazy. I monitored some values with Fiat ECU Scan, so values are based on that:

First start every morning the idle speed starts at 750, throttle is about 6%, of course engine shakes quite well. And after 2..4 seconds the idle rises to ~1300 and stays there for a while than lowers to 750 as the engine is getting warmer. On cold start the expected idle speed is ~1300 but stays 750 for some seconds, I do not know why. When I step on the gas it rises immediately, so if I start the engine with gently stepping to the gas the symptom can be hided.

Is it normal? No fault code is present, no poor gas reaction, just tricky start after longer whiles.

The other is the idle speed "flatness". Throttle position varies continuously a couple tenth percent which makes idle speed variation like 20..30 RPM. I read somewhere that 30RPM variation is just normal, but I never seen such a symptom on my cars, neither on my MKII Panda (ok, it has a separate idle motor) nor on the 1.6 Astra. I can hear the variation which sounds worse (faster variation) when load is engaged, like high beam, air conditioning.

Is it normal? Mechanic says he cleaned the throttle valve with cleaner. Shall I disassemble and clean it thoroughly?

The car just had a new battery and new filters, spark plugs, engine oil, coolant...

Thank you,
Zoltan

My 2010 1.4 120hp TJet does exactly the same, I wouldn't worry about it. Seems to do no harm, I imagine the ECU picks up the engine isn't running at its best and does its rise to 1300rpm 2-4 seconds later as you say.

Cadabena, thank you for the prompt response! Good news!

Then only the idle speed bugs me, why it is not constant...?

Thanks,
Zoltan

Can anybody add some items to check? I read already many things. MAP sensor cleaning. Throttle body cleaning. Any other?

Thank you,
Zoltan

Happy New Year to all!

Today afternoon I removed the throttle body to check for buildup. It was badly clogged: Video

Also I noticed that the mechanism has a small play, I do not know if it is normal... but due to the spring tension it should not be an issue.

Also the intake pressure sensor had some leftover material on it... maybe oil vapor, humidity, petrol mixture?

All cleaned, built back together and tried to run throtthle relearn procedure as written in https://www.fiatforum.com/newbie-central/292687-throttle-body-relearn.html

But after 25 minutest the engine was still around 85degC, ~2degC outside temperature, so it was unsuccessful - fan did not start. Fortunately it may not be required. Engine runs smooth, throttle position is not varying much - stays around 1.5%, was around 6% before the cleaning. Idle is between 729..752 variation not noticable in the sound. Prevously the fluctiation was even worse when some load is engaged. Now it slightly drops and reaches the above values.

Also on todays first start the engine speed picked up the ~1300RPM immediately, with no delay.

I'll post a follow up in some days.

zoltanpapp82 said:

Mechanic says he cleaned the throttle valve with cleaner. Shall I disassemble and clean it thoroughly?
Zoltan

Click to expand...

It is time to change the mechanic !

Having 6 cold starts since the cleaning. So far it is working fine: raised idle kicks in immediately, good hot idling and "load management".