Throttle Response

[monVR6 0]

Hi all - not really a problem - more an observation, but not sure where to post this ! Anyway, when giving my VR6 some welly, it pulls hard (of course), however, if I accelerate hard, take my foot off and then re-apply power immediately (so the whole process takes less than half a second) - it seems to pull even harder. Not sure if this is just an illusion - or whether the cars not breathing as well as it should.

 

Any thoughts ?? Car has an AmD remap and K&N Panel filter

[Bolster 0]

Or a fuel supply prob?

On the odd occasion mine will starve itself of fuel fangin round a roundabout but easing off then on again (usually in the change of direction off the roundabout seems to let it catch up with itself (?) and boom - off we go again.

[andycowuk 0]

This is an effect of throttole transition that the engine management *attempts* to correct, to varying degrees of success. When the throttle is suddenly opened wide, the mixture in the cylinder becomes weak due to the air being lighter that the fuel, air fills the cylinder more quickly.

 

The ECU can detect transients in the throttle position, and compensate for the above by injecting more fuel, thisis known as acceleration fueling.

 

I dont know if the VR management copes with this well or not maybe someone else can shed some light on this, but I am certain the G60 is crap at coping with it.....I assume this is what people call digi-lag?

 

the above is not a simple case of fuel starvation, there could be an ample suply of fuel, and this will still happen.

[Bruno 4]

I dont know if the VR management copes with this well or not

The ECU is meant to handle this and normally does, even on full throttle depression. I suspect that you have butterfly flutter on your throttle body. There are a few threads around on how to clean the throttle body. I suggest you do, and at the same time make sure that all of the airways are absolutely clean. Be careful with the MAF sensor that lies between the air filter and the throttle body - go out of your way to ensure that the thin wire that runs across its is not damaged when you do clean things out.

 

If this fails. Disconnect the battery for 2 hrs and reconnect it. Then take the car through a range of low and high torque driving exercises including a high speed run. If it comes back after 20 mins or more, then you have to look at the O2 sensor and check that it is clean.

[Kevin Bacon 5]

I suspect that you have butterfly flutter on your throttle body

 

I doubt it with the strength of the VR throttle spring.

 

then you have to look at the O2 sensor and check that it is clean.

 

I take it you don't mean the O2 senor's tip as that's designed to get dirty!

 

K