1.8T pulsing power at WOT

[E_T_V]

As suggested by a forum member I'll split my issues into seperate posts (most of the other forums I use hate that though!)

The new 1.8T seems to have an issue at full throttle and high revs.

The power pulses irregularly.

Any ideas of things to check.

I've had suggestions of boost leak

Could it also be the fuel pump issue of the pump unscrewing itself (its an 05 plate).

What about the boost modulator valve? Are these reliable/flakey?

Any other suggestions as I can't thrash it without knowing it is ok.

Do the diagnostics display MAP pressure? If so at least I can check the boost easily. What boost should it run as standard?

[chrissyboy]

if you meanthe car jerks when putting your foot down it is most likely a coil pack ,failing that a ht lead .

[E_T_V]

No it isn't a misfire from a poor spark, its a definate pulse in power (irregular). Only when really under full throttle at high revs (5k+). Feels like a reduction in power not a complete absence of it if that makes sense.

No rough running at any other time either.

[Thomas]

Could be the vaccum hoses

see this thread sounds similar to yours

http://www.the75andztclub.co.uk/forum/showthread.php?t=136053&highlight=turbo+hoses

[E_T_V]

Will check the actuator and boost controller pipework.

What boost do they run and what is the actuator pressure supposed to be set at?

[VVC-Geeza]

Standard boost is 9psi.

You could try bypassing the solenoid to see if it smoothes things out,not uncommon for these to become faulty.

Check the plug gaps,and if necessary reduce to 0.7mm.This solves many running problems.

[E_T_V]

What boost will it run on actuator pressure (just to check it is adjusted right as it has had a new turbo at some point).

T16's used to run 7psi actuator pressure and the BMV modulates it up to 11.5psi at high revs.

Is this similar on the K turbo? And why it is it modulated? On the T16 it was to protect the fragile gearbox. I hope it isn't the same on the K turbo as I've had my fill of rebuilding gearboxes!

[Hogwarzt]

I have to agree with VVC-Gezza.

By-pass the solenoid. Car should run fine but reduced power. This will rule out the solenoid. This will only work if the pipes are conneted and intact.

Rich

[E_T_V]

I'll take a look. Anyone know what boost it should be running so I can verify it is working properly (or otherwise) as the original fault seems to have gone away.