Forum » General Tuning Discussion » Cam Timing 2ZR-FE

Cam Timing 2ZR-FE

General Tuning Discussion

Forum Posts

Courses

Blog

Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads

Page 1
Author
705 Views

Hi All,

I have a Lotus Elise 250 CUP with a 2ZR-FE toyota dual VVTi engine. Running ECU Master EMU Black.

And I have some issues with Intake Cam timing. (Trigger and VVTi settings are from ECU Master base map)

From the Lotus and Toyota Service manual the specs are:

So I supposed to have a 55° room on the Intake Cam to play. But I am only able to advance it 45°. (The Exhaust Cam is moving nicely in the 40° window)

What i am missing here? Trigger setup maybe?

What do you Guys think?

Many thanks in advance!

What have you tried changing? I see there are limits for min/max duty cycle, perhaps it needs more than 70% duty cycle to to reach a more advanced angle. What is the duty cycle when it's at the maximum advance? What is the commanded (requested) position at that operating condition.

Usually I try to plot the CAM angle target and measured angle on the same graph so I can see how well it tracks.

Log that with the duty cycle of solenoid output 1.

I just wanted to test full advanced at 55°. I tried at 100% max duty cycle as well, but not going over 44,5°

On the log the black line is the commanded so 55° and blue is the measured so 44,5°

When I unplug the selonoid, than cam angle is -0.5° so Cam Offset should be ok. So from -0.5° to 44,5° moves the cam 45° ok, but somwhere missing 10° :) Should be operatin range 55° if the service manual correct.

Perhaps someone has installed some range-limiting into the VVT mechanism, this would typically be done if different cams or pistons were fitted. It important that the VVT mechanism can never allow a valve/piston interference -- so even if the ECU programming fails, it can't mechanically hurt the engine.

44 deg is a lot of CAM advance, and is similar to what I've seen in the VVT engines I've worked with.