almost ever time mostly in 3rd 4th and 5th it get boost cut fuel cut. Changed plugs with bpr7es .70mm gap tighten piping but i do have small leak on the wastegate, wastegate on order as well, attached video.


http://www.youtube.com/watch?v=RzFy8L-rIxs

 

What mods done to car?

 

as above what mods?

on a standard IV ecu? with or without a tune?

 

Stock evo4 ecu's cannot be tuned.....And are you running a separate boost controller?
What kind of wastegate? internal? external?

That's 1.3 bar!!=19psi!.
Standard boost for 4's = 0.9 bar(13~14 psi)
Anything past that you'll need to enhance the fueling(I went with E6 ecu, 560cc injectors and High Press. 225L fuelpump and reflash).

It's the general consensus on the forums that the stock e4 engine shouldn't be fed over 1.3bar(due to the weak ringlands of the E4 piston design.....rectified in E5 onward).

Honestly i can't make out if that's a missfire....boost/fuel cut feels as if you ran into a wall, as if the engine just dropped out from underneath the car and became an anchor....(at the vids end, though?)
As per the forums the plug gaps are set anywhere between 0.5mm to 0.8mm.

hope this helps a little.....

 

Running evo VI injectors with evo VI ecu 255 fuel pump not yet installed 3" exhaust. camed not sure what kind 255's I believe tho the guy I bought it from didnt know much about what was done to the car. Like I said I did find a leak on the stock wastegate order new OEM wastegate hoping this stops once I put the fuel pump and wastegate in...

 

cutting at that boost level is 100% normal.
You can move the cut with Ecuflash and a 2.0 cable for the evo6 ecu. I did this on my car.
but obviously you'll want to get a full retune.
Leaning out the fuel mixtures with a near stock car will get you 40-50whp.
Increase the boost for more power. Max on stock injectors and 255lph pump is approx 250kwatw (340whp)

Cheers, Mike

 

this happens to me at around 20lbs of boost.. could it be because i have a leak on manifold . im tunned and have 255 walbro. am i hitting fuel cut?

 

it could be I'm pretty sure i got an exhaust leak as well... but like I said before have no clue why.. putting the 255 in this weekend so will see how that goes with it hopefully it fixes it.

 

If ur not boosting. Either the turbo or vacuum leak somewhere. Get it checked out

 

just an update got my new oem evo IX wastegate fixed the problem....

 

Good to hear. The WG Slipped my mind

 

By wastegate do you mean actuator or the turbine housing itself ?

Also correct me if I'm wrong but I think Evo 4's were the first of the reversed twin scroll 4G63T engines and I think they had the smallest 9cm turbine housing size std .

If thats the case I'd be getting hold of any of the 10.5cm turbine housings and preferably the later single flat valve version from the 8MR or any of the 9's .

Turbine inlet pressure and heat will make life hard on your pistons and along with combustion temps is the most likely thing that will kill them .

A .

 

the actuator is was leaking like a ***** and just spooling up to no end but the new wastegate actuator isn't connecting smoothly it has to much tension i think i need to shim it out from the turbo some so it fits smooth with no resistance