Turbo surge in 2nd gear

[PSX]

Been doing a bit of digging on this one and think I'm close to the problem so will keep it brief:

In-gear acceleration in 2nd from the bottom of the torque band (2100rpm) to maximum boost and about 4500rpm - I lift off the throttle sharply but the car continues to accelerate, the turbo surging up to around 5100rpm - accompanied by a few flashes of the TCS light (this may be incidental - greasy road). This is confirmed because if I jump straight to the brake in this situation, I can feel the engine pulling against the brakes.

Sticky diverter valve? Car is a standard LCR225.


Cheers,

Alex

 

[DJ-LIAMC]

Bet that is scaary i think you are right about sticky dv, check it out.

 

[Gubien]

I've tried that too, feels like it just want to accelerate even though I'm not on the throttle. I know for sure that it's not my DV sticking.

 

[traumapat]

Throttle body sticking?
Id look at dv first. try a yellow spring if on the softer green. (if running a forge)

 

[andycupra]

ive had this.

IMO its a bit of a fault with leons, im sure a few had reported this to me at a meet some time ago.
For me at least its not a sticking DV, unless ive been unlucky with both oem and forge items.

No idea what the issue is, however it does appear to happen rarely when you are hard on throttle let lift off very quickly. I was thinking it was a accelerator potentiometer issue. (or whatever is used to measure throttle position)

 

[Deleted member 43482]

I get this slightly also, although I notice it more when changing gear, the revs rise between gearchanges unless I pause between taking my foot off the accelerator and pressing the clutch. I wasnt sure whether this was just a characteristic or whether I have a slight problem somewhere, maybe the N249 bypass would help this?

 

[PSX]

Just to close this one up, managed to replace my DV on the 30th of december, two weeks road testing and it looks like the problem is solved - much quicker response on lift off and improved partial-throttle handling, although there is a very slight sensation of surge still when doing the in-gear acceleration in 2nd to 5k revs or so. I figure this is probably the most boost the engine makes though, so to release all that is a big ask for a stock DV.

Incidentally my car is an 05 and was fitted with the 710P (uprated part also fitted to RS6 twin turbo) - I've now replaced it with a 710N, can't seem to pick up on any adverse effects from having it though.

Alex

 

[Mark300zx]

I found mine disappeared when I cleaned the TB!