Newbie in trouble

[Efini]

Well, I just got myself an RS2 with some problems the previous owner couldn't sort out. Now it's my turn to have a go.

Background: It has an MTM-chip, open K&N filter, aftermarket dump valve and the cats are removed. It also has an aftermarket (harder) spring in the wastegate.

Problem: When I get to 3000rpm boost starts to build up. I goes up to 1.6-1.7 bar for about a second. Then it starts to fluctuate between 1.1 and 2.0 bar and the car is just jumping and jerking..

I tried to put the original WG-spring back in. It didn't solve the problem, but at least it got the boost away from the 2bar area ..

I was looking at the system today and was wondering about a few things here:

[Greg_S]

I can see most of the problem straight away. the valve you have fitted is not a re circ type which can cause maf problems. You should fit a re circulating dump valve. the 710N P/N one from audi is about £25 and does the job just fine.

that valve is teh WGFV Waste Gate Frequency Valve which controls the max boost via the ECU.

And unless the car has been tuned with a harder spring it probably shouldnt be fitted and wants the standard spring putting back in

Greg

p.s. welcome to the forum

[Paulm]

Waste gate frequency valve. this controls boost, it gets signals from the ecu

the pipe is block off because u have a vent to atmosphere dump valve. The blocked off bit is where the original dump valve vents the bumped boost back into the system.

HTH

Paul

[Paulm]

too slow as usual

[Efini]

Thanks for quick response guys!

I have the original dump valve laying around here somewhere. I'll try fitting it back on and try it like that.

Damn... I'll be loosing some of the cool sounds then...

[Doug_RS2]

You can still get a very cool sound from Forge Diverter (yours looks like a Forge dump valve) - Mine chatters on gears changes (becasue of the metal piston inside it) and you can hear the woosh.

[Efini]

I now have the stock DV back in the car. But..

On accelration it boosts up to about 1,2bar and then begins to jump and jerk with some severe backfire.
Think I'm gonna try and find myself a new O2-sensor/lambda today, and a new set of plugs.

[Sir Buff]

I have also this Forge dump valve in my S2 without problems.
Changing the WGFV could help.
If not try the original Wastegate Spring.
What says the ECU, are any errors in the log?

Sorry for my bad english.

[porkkis]

Could also be dodgy ECU software. Perhaps it was ment to be used with the dump?

[Efini]

I checked out my WGFV today, and the brown housing is cracked in several places. Could this be a possible cause?

[Efini]

I checked out my WGFV today, and the brown housing is cracked in several places. Could this be a possible cause?

Oh yes it was! I taped it together and went out for a spin.
It runs like a dream!

But... It boost at a steady 2bar!

[Greg_S]

2 bar is conrod bending levels. get a new WGFV. it sounds like the valve is stuck open so boost will go as high as the turbo can do and you are probably over spinning the turbo too.

Greg

[Efini]

A new WGFV is now on its way, thanks for all the help guys!