Hello,

Im quite new to evo so i apologise if this is a noob mistake..I have a fuel cut issue that i cannot solve.

Car is an evo 7.

The Boost Cut Limits are all set to 319. (Attached .JPG)

car tends to fuel cut at around 300 loadcalc. It will cut in any gear and is not rpm specific but always happens at a point of heavy load usually at wot between 3600 and 4200 rpm.

In the attached evoscan log row 22 TPS hit 100, i get some knock from 1 to 5 but the cut happens in row 64 and 65, I have many logs some with knock some without but the cut happens either way. Car is running abotu 22PSi WOT in 4th. If i turn the boost back to approx 17PSI it does not cut.

I appreciate any clues to solve this.

 

It's due to the IDC getting too high.

Need bigger injectors.

 

Should i log and see what its at?

If i buy bigger injectors what size would i need to run E85 in the future?

 

Yes, then you'll know and won't need to ask.




Measure everything.

 

I have logged duty cycle before and it didn't seem to go higher than 83% but I will do another test. Also the cut out is instant, there is no missing sputtering our anything. Is that what I would expect? I have not heard of evos needing bigger injectors for standard turbo and 22psi?

 

you have an boost leak...
its simply not possible to hit load 300 at 22 psi......

 

The issues so far..

I made up a bike valve attachment with pluming supplies form Bunnings to conduct a boost leak test, I couldn't get more than 5psi on the first test . I realised that my MBC is a boost leak so i closed it off and tried again but still only 5psi.

I went and bought a new set of clamps and removed the front bar and intercooler, I tested the intercooler on its own out of the car and its fine, i removed all the silicon piping, cleaned everything and re-sealed with new clamps. tested again and got to about 10psi - better but not ideal, i then checked my recirc bov and it leaks at about 5 - 8psi, in my old wrx i could adjust the pressure of the bov but in the evo i turn the piston but it doesn't seem to make it any harder to open, is it stuffed or this normal?

Now i only need 4 full turns of the MBC to achieve a steady 20psi where as before i needed 11 full turns to achieve that boost.

After this i no longer get the fuel cut but i had to remove some timing as i had knock at between 2500 and 4k revs at loads of about 100 to 140.

I'm not sure where else the leak could be? i checked the injectors and throttle body but all seems ok, could it simply be the dodgy bov?

The car is running better than ever except when i log with evoscan i now get Knock on deceleration and usually in 2nd gear, i don't understand how this happens or how bad it is?

thank you to everyone for your suggestions, I'm getting closer to a happy Evo!