Dropping boost and lumpy running.........

[AdamR]

A problems developed on my Tubby, and tbh its pi$$ing me right off!!

Last couple of days it wont hold 1 bar of boost - it'll build to it fine, but then after 5k rpm, it starts to drop off down to .75 bar.

Also when its cold its runs quite lumpy and hesitant

Any suggestions?

[AdamR]

UPDATE
It seems the problem is intermittent, as yesterday it was fine when I drove out, parked up, when driving home wouldnt boost past .75bar again.

Any ideas? - I'm currently suspecting a boost controller problem (its a greddy profec e01) as a friend had something similar a while ago.

[Driftlimits Performance]

Check the vsv isn't plugged in.

I had my clutch done a while ago, and Mr.Clutch kindly plugged it back in for me. It would boost up to my Greddy (profec B2) settings of about 16psi, then drop to 13psi.

[AdamR]

Cheers!
Wheres the vsv located, and whats it look like?

Thanks in advance

Adam