Revs Increase After Foot Is Off The Pedal!?

[simba7]

Hello,

I cleaned my throttle body with carb cleaner and this fixed a startup idle issue i was having.

My car does speed very nicely now.

However now when i drive and let go off the accelerator, my car continues to speed for 2 seconds before slowing down.

Im not sure what could be the cause. Something probably needs changing.

Can anyone help?

Thank You

[darkmast3r]

Interesting.. My 1.5 dci does the same thing if I dont let it idle for a minute after starting, but seems ok in warm weather. I thought it might be something do do with auto choke or along those line. Hopefully someone can shed a little light??

Edit.... Upon a little searching if it's a diesel like mine it could be the EGR valve needs a clean or if its a petrol it could be the throttle body needs cleaning.

[simba7]

Mine is a 1.6VVT and it only happened after i sprayed carb cleaner into the throttlebody.


I cleaned it all but its started doing this. It is more responsive but it seems dangerous to ignore the problem.

[AlexB]

simba7,

The throttle calibrates itself the first time you start the engine after disconnecting the battery. If it was not disconnected, then cleaning may have upset the calibration. In any case, the correct cleaning procedure is a technical note in the sticky thread.

[AlexB]

darkmast3r,

There is no auto-choke there... This may have something to do with the throttle pedal. Have the OBD codes read!

[simba7]

Thanks for the reply Alex.

I took it out and cleaned it and then took the battery out to charge at home.

Reconnected it and its been doing this since.

I did spray carb cleaner directly into the engine while it was running and it did cut out so presumely it got rid of some carbon but perhaps it took a sensor with it.

If the engine light isnt on, does that mean there is no obd code? Mine never lights up to indicate a problem so i never check it.

Thanks

[AlexB]

No, there can be OBD codes logged while the light is not illuminated.

Have you read the technical note 3799a (the sticky thread...)? It mentions that a certain O-ring has to be replaced.

It also says that sometimes the throttle body may need calibration:

With the fault-finding tool reinitialise the
programming of the thrust bearings:
● (for injection systems S2000 or Sirius34) use the
erase command RZ008 "Reinitialise
programming".
● (for injection systems S3000) use the erase
command RZ005 "Programming".
When the ignition is switched on, the throttle valve
should go through a cycle of programming the MINI
and MAXI throttle stop positions.
Using the fault-finding tool, check that the
programming has been carried out correctly:
● (for injection systems S2000 or Sirius34) message
title "Programming Throttle Stops" ET111.
● (for injection systems S3000) message title
"Programming Throttle Stops" ET051.

[darkmast3r]

Cheers AlexB, I'll get my reader out to see if any codes are there. It only does for a minute at the start. If I leave it to tick over for a minute as soon as I drive off it is fine.
Edit.... Just checked for fault codes and none are stored. This only happens when left overnight, it doesn't happen when I drive to work and leave it in the car park for 9 hours then drive home. Maybe its just characteristics of the car itself and it doesn't happen when the weather is warm.

[AlexB]

You may want to plot the live parameters in order to see what is actually going there. The first minute the O2 sensors are cold, and the engine is in the open loop control mode. You need the live sensor readings!

[simba7]

Got it. Ill plug my elm in and see what the readings are in the morning.

Are there any free applications you can recommend?

Thanks

[darkmast3r]

Easy ODB is quite good but basic but does give you some readings and can reset the fault codes. Digimoto 5 is quite good but its not freeware.

....I've just took my EGR valve out and it was absolutely caked in black soot so i got the carb cleaner out. Gonna see if that makes a difference.

[simba7]

Today i attempted to take off my map sensor by pulling it and it snapped!?

Now i have had to tape it on for the car to run properly.

Will have to buy another one as soon as before the tape peels off.

Does anyone know how to remove a map sensor properly and how to fit another one?

i thought it was a simple pull to remove and push to fit?

Thanks

[simba7]

Managed to sort it now the map sensor bit.

Will check readings from car.