Engine won't rev pass 4000

[preludekid]

Hi everyone,

I need some help here as my car won't rev up under boost.

I am now limiting the boost to 0.6bar (aprroxmately 42%DC) . I am trying to rev up to 7000 under 0.6bar to dial in AFR and get familiar with knock signal.

Under WOT, boost build up and engine climb to 3500+rpm then suddenly cuts power. After that, my right foot let go naturally (see log). Anything I forgot to switch on/off, or any setting not setup correctly?

Is a Cosworth YBT, stock turbo/internal, with upgraded fuel pump/injector, plus K20A COP. Thats all. Nothing fancy.

Log 2020-07-5 5;44;01 pm.llg 20200628.pclr

[Adamw]

Can you do a similar PC Log with all parameters logged, the ECU log doesnt have many channels that are useful for diagnosis.

Also, you are on very old firmware - like 5 years old.  It would be well in your interest to update that before tuning much further as there have been several improvements since then, especially knock control.

[preludekid]

Hello Adam,

Today I use my laptop to log it again.

Updated firmware as well.20200712.pclr

I lowered down my WGate % from 42 to 40. RPM now hardly goes over 3000rpm.

Log 2020-07-25 7;06;20 pm.llg

Edited July 25, 2020 by preludekid
wrong map

[Adamw]

I dont see any obvious ecu related misfires in your log, no cuts commanded etc. 

I notice your trigger offset is still at zero, have you checked the base timing?

Have you tried adding 15% fuel just to see if it is better or worse?

[preludekid]

Hello Adam,

Today got sometime to go outside to try again. I switch from open loop boost control to close loop. No luck.

My son hop in for a ride, I can't do a PCLog. Close loop boost control still got the problem. Can't go over 3000rpm.

However, I back off the throttle a little (70%), it revs up to 5500rpm. Please neglect it is lean, I added fuel right after this run.

Noticed that, throttle percentage from all of my previous datalogs. There were all back off to Zero% before the rpm drops. Look at my screen capture that I high lighted.

Something wrong with my TPS?

Log 2020-07-26 6;07;11 pm.llg 20200725closeboost.pclr

Also, there are so much unstable area in today's run. 

In the screen capture, the red circle has a smooth afr, and right on the target (still using open loop). But the blue area are very bumpy, the ride was very rough.

Technically, same load cell, same IAT and ECT. What causes that? 

[Adamw]

10 hours ago, preludekid said:

Today got sometime to go outside to try again. I switch from open loop boost control to close loop. No luck.

It is nothing to do with boost control, your turbo is barely even spooled by 3000RPM.

 

10 hours ago, preludekid said:

Noticed that, throttle percentage from all of my previous datalogs. There were all back off to Zero% before the rpm drops. Look at my screen capture that I high lighted.

Your throttle position sensor is likely rotating off the end of its wiper travel.  The voltage is reaching the error settings so the ecu is defaulting the sensor to the error value.  It may be a faulty sensor or it may just need adjustment.

 

10 hours ago, preludekid said:

n the screen capture, the red circle has a smooth afr, and right on the target (still using open loop). But the blue area are very bumpy, the ride was very rough.

Technically, same load cell, same IAT and ECT. What causes that? 

It is a misfire.  When you dont have combustion you have a cylinder full of fresh air pumped into the exhaust system, the lambda sensor measures oxygen.  The erratic lambda usually means you have 1 or 2 cylinders misfiring.