Boost issues. Driving me insane.
 

Mods on car -
EJ20 fully forged
Manual boost controller
Apexi boost gauge
TD05 turbo
440cc injectors
6K ECU with mappable plug-in daughterboard
Updated new age coil packs
PFR7B plugs (1 week old gapped to 0.7mm)
Turbo back 3 inch system
Apexi cone filter kit

So far I have changed the following -
Fuel filter
Spark plugs
Boost control solenoid
Map sensor
Fuel pressure regulator
Fuel pump with new filter sock
Re-wired the coil packs
New turbo up pipe

Intermittent boost issues and I've tried all sorts. It's more of a fuel cut feel than a misfire. Often it will hit 0.5psi and hit what seems to be fuel cut. Wednesday night we changed fuel pump and all seemed hopeless even after resetting ECU. Parked it up for an hour and hey presto it was fixed! Hitting full boost and pulling hard (Spiking at 1.3 holding at 1.1)

Drove it for an hour or so then next day back to normal again. There's no noticeable cracks or splits in anything. We ran the engine and sprayed over some of the lines with brake cleaner and still nothing obvious.

Does anyone know if you're supposed to run a restrictor pill when you run a manual boost controller? Because there isn't one in sight.

I'm yet to change the vacuum lines just waiting on them to arrive anytime now. Anyone have any thoughts on what it could be? One thing I haven't touched is injectors. Also I don't have a FCD am I right in thinking the plug-in mappable ECU should have that covered?

For a start take that crap mbc off its most likely the ecu seeing too much boost and giving a fuel cut to save the engine, the ecu is what controls boost so why try and trick it. The reason it runs ok when the ecu is reset as it forgets the overboost problem then shuts back down again when its not happy, put the origional boost control system on and map the car properly.

Out of curiousity how come it didn't make a difference when I switched it back to the OEM boost control solenoid and reset my ECU?

It seems to have a load of modded parts on it, has it been mapped?

Yes mate but it was mapped before I imported it over here. My mate also said its probably down to the mapping but it's been gradual problems. Was fine for awhile (week or so) then more and more of the fuel cut issue now it's pretty much constant except for wednesday where all was temporarily fixed

imported from where, japan? if so then its mapped for jap fuel, needs mapping for uk fuel and that mbc removed.
and what is a "mappable plug in ecu" sounds like this car needs properly looked at before its kills its engine

Imported from Japan to England originally then went off to Lithuania to a friend of a friend and I bought it off him and brought it back over. It was mapped in Lithuania.

It's a daughterboard that plugs into the existing ECU.

Just tried running pure waste gate pressure by connecting that vacuum line from the turbo straight to the waste gate. Held 0.5 bar no problem but still hit fuel cut. Any ideas anyone? Am I right in assuming the waste gate is fine and my fault is elsewhere?

Ok I think I've solved the problem as I am now hitting 1.0 bar of pressure.. It looked to be a rusted metal EVAP line. Anyone know if this 1 way valve for the fuel line is necessary with a parallel fuel rail setup? Because we think it's pointless and unnecessary


https://cimg6.ibsrv.net/gimg/www.sco...2524a31673.jpg