well, it started a few weeks ago, and has only appeared seemingly random when i accelerate hard.

The car kind of breaks really hard, it happen so quickly i couldn't notice if the rpm was affected or not, neither anything else since i am trying to prevent my teeth hitting the steering wheel :p

but when this happens it only is for like a fraction of a second and everything is normal it seems like.

i think the engine is causing this, either by misfiring or something else.

its really hard to explain since it happens so quickly and everything is normal afterwards, so anyone have any idea what to check?


This is a Rover 620 turbo 1997, driven 220K kms now actually :)

sounds like ur hitting boost cut what psi boost are u running?

you might be right, since a little time before this starting to happen the car was alot quicker and the turbo made much more sound when i let go of the pedal when accelerating.

My car is running stock setup on everything, so something must have been broken for it to probably running a higher boost?

any idea what i should be looking for, or how to check this?

check the hose from the boost controller to the actuator. It commonly goes hard cracks and leaks giving uncontrolled boost which usually destroys the engine.

well, did check all the hoses, but they all seems fine,no cracks that i could see.
anything else i should be looking at? the boost-controller itself or?

Replace the hose anyway. The cracks will be hard to see (or pressure test it if you don't want to swap it)

I did replace the hoses, i am kind of afraid to test if the engine stalls, but it still has the same kick when i accelerate as before, so i assume it still over-boost...

how damaging is it when it over-boost?

It melts the pistons meaning a total engine rebuild. So you don't want to do it for long periods.

Fit a boost gauge and put in say 3rd gear and accelerate with you foot to the floor. If the boost gauge goes over 12psi then lift the throttle as something is still wrong.

well, there is something wrong still :/
i accelerated in 2nd up to about 4K rpm when it stalled like before...

any idea what i should check next? and how?

What was the boost level?

i've finally bought a boost gauge, and it reads 1.2 bar when it cuts.
this is with standard boost controller and everything, does this mean its not working?

up to about 4K rpm it doesn't read above 1 bar, but it spikes up to 1,2-1,3 bar after that.

what should i do next, the hoses and everything has been replaced.

what should it read anyway, max boost? i got a manual boost controller laying around i could use.

It is overboosting, normal maximum boost is about 11.5 psi which is 0.79 bar. 1.2 bar(17.4 psi) is extremely high and the ECU will cut ignition to protect the engine from damage. Try to blow into the wastegate actuator to check if the diaphragm is ok. You should not be able to blow through it, if you can then the rubber diaphragm inside the wastegate actuator can is split and the waste gate will not be able to open to limit boost.

i was told on the other forum to bypass the standard bost controller to check what teh boost is.
he said it should be 7psi all the time.
as i said to him, doesn't that mean it can boost to "infitify" since there are no boost controller to limit it?

well, i did what he said, and bypassed the boost controller and connected the actuator directly to the throttle body, and it only
boost up to 0,5 bar, 7 psi and is staying there nomatter what rpm.

so i guess it is the boost controller that is broken?

well, i fitted my Power-tek boost controller, and wound it all the way out.
and i took the car for a test ride, and it boost to 1 bar easily without any stop.

i tried adjusting it, but it boosts to 1+ bar or till the boost cut nomatter what i did, tried even wouding it all the way in, still no change..

i tried also blowing in the hose to the actuator, its airtight allright.

what do i do now, seems like i've tried everything...

well, i connected the mbc to the air-compressor and tried alot of different settings and sat it according to the gauge on teh air-compressor, and i noticed there are like one turn from 1 bar to 0,8 it seems like.

but i put in back in the car and took it for a drive, and a quarter turn from what i got from the air-compressor, and it never went past 0,8 bar.

so i guess everything is okey now :)

thnx :)