DrLoch

FMG, I wish I had answer for that. There are so may things that can cause a miss, from the fuel used, to any fuel related contamination issues, such as ring seal issues to one thing these DI motors suffer from oil contamination of the inlet air via the PCV valve system. Weak coil output, whether it be from low input voltage or a coil that is getting old. Most have tried to move the coils around to see it that helps.

I have intermittent misses from time to time and it's not when I'm in full boost. Best thing to do if you have the means is log looking for that specific issue. From the logs one would be able to see if the miss is from one cylinder or all cylinders.

drspock

Ok changed the plug gap to .020, Fixed the misfire at 20lbs boost. Car is a rocket again. Anyone have a variable gap plug invention they want to share Lol. Also some investigating shows the K&N filter cannot handle the flow with 20+ lbs of boost. So i have to find a larger filter or replace the the cold air setup with one that does not use the filter air box. I see there is room for larger filter in the box than what K&N gave me. All in all i still believe the Turbo is leaking oil and ,maybe water into the system, so it needs to go. Few people told me Trifecta Tune is crap and may destroy my motor so i may switch to another

Oldblue

Do you have this K&N set up now?

https://www.knfilters.com/blog/stree...vy-hhr-ss-2-0l

Or are you thinking this to replace the cone filter in the stock air box

https://www.knfilters.com/search/pro...px?prod=e-1989

DrLoch

Glad to hear you've had some improvement. I am using the factory box with a factory filter, K & N inlet to turbo from box both IAT temps are good with it.

Finding the magic plug is simple, you keep increasing the from .020 until it starts to miss and them go back to the other....

FYI I'm boosting 22 -24 without any issues except for the clutch and cv joints. Back in the day Trifecta was on of the 1st to come out with a decent tune for these motors. Never looked at one to be able to tell you what they were doing, I believe his tunes are locked, but, a number of others have changed to others.

2005HHRauto

Trifecta tunes caused issues...

To the OP:
Your 'tune' is trying to provide more power for you, but can't, as your low-side fuel pump is weak as you stated, it should be over 60psi, mine is putting out 72psi.
Also you stated that your intake valves are 'coked', so the means that you are screwed...

drspock

Maybe, but it hauls ass once again

Yes this is the K&N setup i have. My test show the filter is restricting at 20lbs boost. Im going to modify the air box and find a larger filter. There is room for about 2" longer and larger diameter filter

I wish it was easy to remove this motor. I would feel better with custom rods and pistons. Although maybe it can be done in car, not sure. No time lately to figure it out.

Has anyone installed the performance cams? i like to know what you think. ZZ claims substantial gains even with the smaller cam setup.

Oldblue

You would’ve better installing a larger diameter air intake hose, say 4 inches.

donbrew

Why do you think it is not easy to remove the motor? R&R is 8.5 hours flat rate.

Only 4 bolts holding it in.

You can get the oil pan off in the car.

DrLoch

I've never taken the time to investigate that, in your testing where you logging for vacuum between the air filter and the inlet of the turbo?

drspock

Yes! im going to attempt to install a K&N RX-2820. There is a notch in the airbox that can be removed to allow another inch or two in length and there seems to be a little room for larger diameter. Getting out the measuring tape. The RX-2820 is one inch longer and also has filter material at the end for additional flow. The flange is 2 or 3mm larger so it will require a rubber spacer also. And yes i ordered a new low pressure pump as mine seems to linger at 45 psi and never 60. All in all its fun taking on so called fast cars and very expensive imports. They hate to see my ugly car show them up.