hello, recently converted my legacy twin turbo to single turbo and it hits boost cut at 10psi

has a ej20r with vf30 hybrid
greddy profec b spec 1 boost controller
japspeed 3" decat with h+s catback

have changed ecu and map sensor but problem still remains

stock bcs is blanked off as running the greddy but still cuts

revs to redline if kept under 10psi

 

The ECU needs reprogrammed to raise the fuel cut, that's what's wrong.

 

It's the map sensor that gives the pressure reading to the ECU so blanking off the solenoid won't affect this.

 

have tried a stock sti ecu and also a prova eifel sti ecu, even still the stock ecu should cut boost at about 17psi and the map sensor can handle 1.15bar

 

Yeah your right there, should be working about those figures. Do you have a restrictor pill fitted to the vacuum pipework?

 

The map sensor should be fit for about 1.7bar btw

 

havnt got the restrictor pill fitted, read you dont need it when running a ebc

only the pressure select solonoid and the map sensor are plumbed up on the bracket as the stock 2 port bcs is blanked off, the ebc is fed straight from compresser to the ebcs back to the actuator

 

I had a blitz boost controller on my impreza and it had a setting that would mimic the effect of a pill. Even at that I still had my pill fitted and didn't have any issues at all. Just hitting the fuel cut at high boost levels.

It seems the MAP sensor is getting a surge of pressure from somewhere? Either that or the boost gauge is possibly reading wrong??

 

I have a couple of spare boost gauges to try

 

Good stuff mate. Any updates?

 

yeah tried a lamco gauge instead of the ebay cheapo gauge but still says 9-10psi before it cuts

After I rushed the conversion I got a oil leak and the turbo/uppipe gaskets are shot so going to pull the engine again and replace all gaskets, new oil and change over any boost related electricals to known working ones

also fancy painting the block while its out

 

Strange one. Must be a mix up on the vacuum lines. Hopefully you get it sorted mate, good luck!