Citroen c4 petrol 2.0, with a LPG, 130kw

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dynamics_sila
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Citroen c4 petrol 2.0, with a LPG, 130kw

Post by dynamics_sila »

Hi everyone,
I have notice something with my car. When I am in park position (no drive), it starts to give gas(acceleration) producing about 200-300 more RPM, sequently. It's happend by itself, by the car. Sometimes start also a fan motor which is placed in front of the car.
Is this normal state of the car ?

Thank for your answer
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MattBLancs
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by MattBLancs »

Bit confused about your car's specification: 130 kW = 180bhp = VTS spec. Manual gearbox only, but you mention it being in Park?

Radiator cooling fan switching on when stationary= completely normal, there's no airflow over the radiator when not moving, so even just idling the engine will generate enough heat to need the cooling fan kicking in to keep temperature ok.

Revs building by itself does not sound normal.

If yours is the 137bhp (102kW?) Then depending on age it will have a small idle control motor - these can get a bit stuck and so give idle speed issues. Bit of a clean helps free it off.

If it is a later 137 or the 180bhp then it's a motorized throttle and no idle control motor
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by MattBLancs »

Early type throttle body and idle control motor
Early type throttle body and idle control motor
Have a spare sat in my garage!


Idle control motor
Idle control motor
dynamics_sila
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by dynamics_sila »

Thanks,
It is a manuel gearbox and by in Park , i mean when i stop the car (stationary state of the car), it start to give an acceleration( for about 10 sec , but when i drive 1000 km for one day, then it can give acceleration a little bot longer, and then it stops to increasse RPM)
The spec of the car VTS C4 130kw Petrol 2005.
So, by changing the motorized throttle body will stop unexpected acceleration in stationary state of the car.
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MattBLancs
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by MattBLancs »

dynamics_sila wrote: 31 Mar 2023, 20:35 Thanks,
It is a manuel gearbox and by in Park , i mean when i stop the car (stationary state of the car), it start to give an acceleration( for about 10 sec , but when i drive 1000 km for one day, then it can give acceleration a little bot longer, and then it stops to increasse RPM)
Ah, ok I understand you, just idling not in gear.
The spec of the car VTS C4 130kw Petrol 2005.
So, by changing the motorized throttle body will stop unexpected acceleration in stationary state of the car.
I would not change any parts as yet, really in needs plugging in to diagnostic and a look at live data - as the throttle is controlled electronically, it allowing more air in to the engine (and hence it increasing in speed) may not be anything wrong with throttle, it's something else confusing ECU and causing it to increase the rpm.

It can't do any harm, but I would suggest giving the throttle body a good clean internally (remove from manifold, 4 bolts = then can clean thoroughly with no worries about anything falling into inlet manifold)

Any cheap WD-40 type product would clean it off well enough.
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Doo
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by Doo »

I think there may be a problem with the LPG vapouriser allowing gas to seep into the engine.

They have a rubber diaphragm which can decay over time & allow the gas to get into the inlet manifold or LPG injectors.

It can be a dangerous situation, so have it checked quickly.
Has anyone seen the plot? :?
dynamics_sila
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by dynamics_sila »

Definitely i wil perform a cleaning of the throttle body. Diagnostic shows everything is fine.

Maybe it is on the LPG (LPG has also his own modul unit). For now it is not possible to see the range of kilometer (picture)
20230401_144857.jpg
, the board shows me that I need to tank the car, even those that it has enough fuel in reservoir. The technician said to me it's normal for citroen/renault/peugeot cars, the ECU take not only a sensor in fuel resevoir in account, takes also how much kilometer is made by driving (something like expresion with 2 parameters). There is possibility to install some kind of emulator, but it is also not a solution. He also said to me , after 10 times of a new starting the engine it perform restarting on a fuel level, which doesn't happend to me.
I use petrol fuel only for starting the engine.

Can I take maybe some hard reset, so it can shows me the level of fuel in reservoir/tank.

Maybe it make confusing on the ECU, showing no fuel.

I will also ask technician to make a diagnostic on a LPG modul. Recently i have drive the car about 1000 km and another 1000 km back home. Everything fine only when i stop the car, RPM increase sequently a little bi longer .
dynamics_sila
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by dynamics_sila »

The final conclusion is the sensor of the throttle body, and it is needed to change the whole throttle body.
But the sequently acceleration in the stationary state accur only when i drive more then 60km in a day.
I need to drive the car on a petroleum fuel for a 60 km in a day, to see what will happend

Something make the ECU to does this action, some sensor (probably temperature) .
On the diagnostics there is no problem.
dynamics_sila
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by dynamics_sila »

There are the pictures of throtle body inside. By default it is a little bit open.
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MattBLancs
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Re: Citroen c4 petrol 2.0, with a LPG, 130kw

Post by MattBLancs »

dynamics_sila wrote: 12 Apr 2023, 20:12 There are the pictures of throtle body inside. By default it is a little bit open.
Image
Image
That makes sense I think, the motorised throttle does away with the need for a separate idle control motor (like on my pictures) and so instead it's held a fraction open and tweaked open and shut by ECU to keep the idle speed correct