Hello experts

Since a couple of years my GP 1.4 8v experience a rough idle with sometimes some vibrations. Also i experience the following: when i brake on the engine i feel a shock coming from the engine. It feels like the air mix completely shuts off. It supposed to be smooth but the car is rough running.

I suspect the throttlebody as dascommand says that the TPS sensor = 86-88% movement Also in idle there is no change almost.


All other sensors are working like lambdas, map and Intake air,w atre coolant.
They all seems to give the right values.


I made a small video from the ticking noise on the throttle body, the sound is coming from the stepper motor (guess this is the idle control valve right? )


have a look, I am curieus about you're opinions.
(unfortunately since it is my first post i cannot link to the YouTube movie)
try it with the part below


watch?v=SLLNXRvIB44

Hi,

The clicking of the stepper motor (this is how we call the idle control valve in dutch) is def. not a good sign. A technician saw the video and said that i have to check first all earth connections form the engine as perhaps there could be a possible ground problem.

Furthermore he stated that it could be that the stepper motor is broken and the clicking is a result of not getting i the wished position, so it stucks and makes the mixture /fuel /air wrong.

I noticed that the IAC is placed below the throttlebody in the intake manifold. It looks like it is just popped in and sealed with a sort of metal spring.

This the partnr: 46553965 (it is the one with 2 rubber selas)

Somebody can help me with a guide how to clean this thing? Or shall i try to remove the throttlebody and clean it from the inside?
I disconnected the blue lead to make a clear picture of this thing

Hi,
as far as i know your car does not have a separate IAC; the idle is directly controlled by the ECU through the throttle plate.

I think that the blue pipe going to that piece is part of the EVAP system; that should make that solenoid the EVAP valve.
You would need MES to properly test the throttle body and EVAP solenoid.

Never thought of this being the purge valve. It is sometimes giving a ticking noise as you can hear in the video link i posted before.

Next step will be to remove the throttle body completely and clean it with TB cleaner completely.

Perhaps the throttlebody is on its way out! For the people with an elm327 device pls let me know the "absolute throttle position" as mine shows 88% with ignition on 86% on idle and 84% at 2500rpm. (With the 88% the butterfly valve is almost closed)

I thought that it should be 0% with contact on , 10% idle and around 20-30% at 2500rpm.

Much appreciated if you can post youre engine type and ATP in this post.

Why do they call that evap valve an idle control valve?

Even fiat shows it with part nr. 71718105 as idle control valve for my grande punto??
1.4 mpi 8v 77 hp (engine type)

http://www.autopartoo.com/oem/fiat/71718105.html

clean the butterfly valve then carry out a throttle relearn

https://www.fiatforum.com/grande-punto/262685-1-2-wont-idle.html



also whilst you have the air box off give the HT leads a fill of silicone grease in the caps and onto the coil pack,

then spray the HT leads with damp start

[ame]http://www.amazon.co.uk/Holts-AQ9R-300ml-Damp-Start/dp/B003IPNBP0[/ame]

this might help with the irregular tick-over especially in damp conditions

Andy Monty said:

clean the butterfly valve then carry out a throttle relearn



https://www.fiatforum.com/grande-punto/262685-1-2-wont-idle.html







also whilst you have the air box off give the HT leads a fill of silicone grease in the caps and onto the coil pack,



then spray the HT leads with damp start



http://www.amazon.co.uk/Holts-AQ9R-300ml-Damp-Start/dp/B003IPNBP0



this might help with the irregular tick-over especially in damp conditions

Click to expand...

Thanks for the hints. I will post results when the cleaning is done.

I did not experience engine tickover but the evp valve was the one ticking.
Perhaps the evp valve stucks? Could that also cause wrong mixture issues?
Andy what are youre thoughts about the absolute throttle position percentage?

I cleaned the throttlebody mainly the butterfly valve and did the relearn procedure.



About the evap purge valve.... Shouldn't there be a rubber seal at the evap valve? It looks like the rubber small gasket is missing.

I will post results how car is idling and driving....

ok, car runs fine in idle and drivers better. there is no seal gasket on the evap valve on the outside so that matter is cleared.

I did some readings with my elm327 device and noticed a few things:

When i do a diagonstic check i got 3 incomplete notifications,

Sensor heater - incomplete!
Oxygen sensor - incomplete!
cataylic monitoring - incomplete!

There is no check engine light or other warning signs on the dashboard.

Looks like the post cat o2 sensor is sluggish as there is very little voltage signal like 0.005 and the signal only goes up when driving the car.
The pre cat give an oscilating signal rich/lean so that one is probably working.

I also noticed 2 other thing: Spark timing advance is around -60 and Short Term Fuel Trim goes madness switching quickly from +100 to -99. What the heck is going on with this car? Please help, much appreciated!

Just a quick little bump. Even in torque with android i have the same -61 spark timing sometimea going up to -20 and bumping min -99 till +99 short trim fuel issues. Can somebody with a gp 1.4 77hp fire engine confirm if these reading are normal?

I red everywhere that short term fuel trim should be around 0 - +4 percent and not bumping from -99 till + 99 all the time as mine does. Timing is also way too retardet. Perhaps it is my elm327 device?

What readings do you guys have?

If you have any ios device (and an elm wifi device) try this app

https://itunes.apple.com/us/app/eobd-facile-car-diagnostic/id713921569?mt=8

If you have elm cable try this (actually this is the best diagnostic software)
http://www.multiecuscan.net/

You need a laptop and cable elm or wifi / bt (but wifi connection only works on registered version I think)

+99 -99 sounds wrong anyway you should have check engine light and a non-drivable car.

Rough idle and poor mileage was due to faulty clutch sensor. I replaced the clutch sensor and the car is running\driving smooth again.

Hi everyone
I have a similar issue to this one, I have a fiat 500 sport 2009
starts fine open loop, closed loop rough idle sounds from the exhaust as if it is missing, plugged in my elm327 using scanmaster long term fuel trim is -93.8 short term is 86.7, ignition timing advance is -59 absolute throttle position is 88.2, and operating in reverse going from 88 downward toward 40ish when revved,
I have replaced the accelerator and the throttle body I have also tested software on a 500 lounge which was ok and as should be the throttle position starts at 15 going up to 40ish as expected,
can someone please help
kind regards and thanks in advance.
Sid