I was going to buy a Tek2.5 from the for sale section, when I met up with the guy and tried it in my car the car had a major overboost in 4th and 5th gear, it would peek at about 1.5bar drop to 1bar back upto 1.5 down to 1bar and just keep bouncing between the 2 without ever settling.

In 1st to 3rd gear the boost would hold just under 1.3bar.

I have now put my standard ECU back in the car and its still doing it only now its through all the gears but at a lower boost pressure.

Anybody got any idea what wrong?

Cheers

Scott

 

spoke about it on the way up the road and it may be your dumpvalve leaking. reason for this being when the pressure is building up the valve could be releasing it therefore not letting car boost properly

 

It shouldn't be doing it with the standard ECU as the boost pressure is lower and it never did it before? I've tried John for any suggestions but hes not got back to me yet.

Scott

 

Has nobody had a similar problem

 

Hi Scott,

I've been having similar problems on my 98 wagon too.

Although i have no boost guage, so it's harder for me to see whats really going on.
I was running a Forge VTA on mine, and the problem started, as you say, only in 3rd-4th-5th.
Took the DV off, and it's still doing it. Only other mods are Magnex bb, and an ITG panel filter.

Have been taking it easy with the car, and lastnight seemed to be the first time i could really give it some stick in third & fourth withough overboosting.

I've heard that high oil levels dont help, so am keeping a close eye on my levels.

I'll try and find the post that i put up when i first got the fault.

Johnny.

 

Ah...here it is.

http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=213338

 

Cheers Johnny,

Its definitely not fuel cut out which I had went setting up a dawes device previously, I'll try cleaning the boost solenoid and see if that help.

Scott

 

You mean 1.5 like this


Thread is here, Big Boost

By the way, Lan-Man's car used to be mine, I was also running a Tek2.5 when I had it (Lan-Man has a different Tek2.5 ECU) and I often got 1.45 peaks, I ended up drilling out my restrictor.

Lost noticeable power after doing it though

 

Mega_stream,

Its not so much the high boost level but the fact that I can't acheive a constant boost pressure, It'll boost to 1.5bar then fall to 1bar straight away then back to 1.5 and continue to jump between the two regardless of how long you stay on the throttle, without ever settling on the set boost level of 1.3bar.

Normally you would expect the boost to peak the gradually tail off as the revs increase.