Jump to content

2jz-gte jumping/chopping badly

Recommended Posts

So my car is chopping really badly sometimes and I dont know why.
It seems like it gets into some sort of cycle and it just gets worse and worse until i either push more on the gas or press the clutch in.
Anyone mind taking a look at the log and see if they can find the reason?

hakking 1 gir.llg 95oktan.pclr

Share this post

Link to post
Share on other sites

You are right, this is a bit of a tricky one, I dont see any obvious reason for the oscillation.  Ignition timing is quite stable and idle valve position is quite stable, so you would expect torque output (RPM) to be quite stable. 

The factor im most suspicious of is you have very large injectors, very short pulse width, so possibly the injectors are working outside of their linear region.  Even though in the later part of the log the Lambda appears to be quite stable, with some set-ups (large exhaust etc) since gas is moving slowly through the exhaust system at idle, the long delay in lambda response can hide unstable lambda problems.   So can you try setting the minimum effective PW to something like 0.75ms and see if that helps - it will cause it to idle rich, but it will help eliminate if injector PW is the problem or not.  I also suggest you make the green area marked below in your Lambda target table all 0.95 so PW is as stable as possible at idle.

If the min PW doesnt help, then the next thing I would look at is get a fuel pressure sensor to log fuel pressure.  How is the map sensor connected - is it screwed directly into the manifold or is there a hose?




Share this post

Link to post
Share on other sites

You are showing Driven Wheel Speed while at idle. 

There is a place where there is no Driven Wheel Speed and your idle looks better. 

Your Gear Ratio Calc indicates that you are in gear and moving. 


Is the ECU getting confused ?

2020-05-22 14_51_48-PCLink Engine Management - C__Users_Remski_Desktop_Downloads_95oktan.pclr.png

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...