2JZ-GTE VVTi Sync Loss at 5800 RPM

[trusts13]

Hi all,

I am experiencing Sync Loss on what appears to be my cam. I know this is pretty common on the Toyota engines just by talking to some experts plus doing a little searching here on the forum. The sync loss appears if I free rev or I am driving. I have a log where this happens as well as a composite log (free rev). I do have Noise Filtering enabled on my crank sensor, but not the cam. I read one this post where a 10k resistor was added and it fixed his issue. I do think he only had issue at low RPM, which seems to be common on the Toyota systems.

I have read about getting a 10k resistor and adding it inline to help reduce the level of noise. I have a very basic electrical knowledge, so if someone could break down which resistor to buy, and how to install it, that would be great. I've attached a log showing a small "pull" where I hit the sync loss. I have a composite log showing a 2 free revs which cause the sync loss, and I've attached my tune. Any advice is greatly appreciated!

Thank you,

[Matt Cramer]

There's a lot of cam noise - try adjusting the VR trim pots on the MS3X.

[trusts13]

Matt,

Thanks for the reply! I actually have a MS3 PRO so pot adjustment. I created a post on Facebook and a few of the guys even have a user chat group which has been real helpful. I also searched the forums quite a bit, and it seems like I am not the first to have this issue. Here is where I am at now:

The general consensus is that while sharing a common ground between the Crank and Cam sensor should not be an issue, I can go ahead and run the Cam sensor ground directly to pin 27 on the white MS3 PRO plug.

Here is how things were:

1. Both cam and crank use shielded wire. They met at one point before the MS3 PRO and the grounds tied in together. The ground then ran into pin 15 for CKP-. Don't think this should have been a big issue. Pin 27, which is CMP (Cam Sensor) negative had a wire that ran into pin 15 on my plug.
2. I tried swapped the pins on the cam sensor to change the polarity. This did not help either. Swapped back since then.
3. I tried running a 10k resistor between the + and - side of my cam sensor wire, right by the plug. It seemed to make things worse, with my sync loss occurring at 5000 instead of 5800.
Was told that this is not enough, need to solder it in differently.

I am going to try the following:
1. Tore apart the harness, stripped out some unused plugs (stock VSV stuff/twins). Main thing here is I separated the cam and crank shielded wire so they are running outside of the main loom.


2. I will be running the black ground off my cam sensor directly to pin 27(CMP - ) on the MS3. No more shared ground.


3. I bought a new camshaft position sensor (part number: 9091905007) just to be safe.


I'll reinstall the harness with the wires adjusted and see how things go. I assume the issue will still exist.
- If it does, I will then try to install the new cam sensor, which shows up this Friday.
- If the issue is STILL present, I will try and add in a 1k and 10k resistor, wired in the following manner...


Hopefully this will clear up my issues. Please let me know if you guys have any other advice!

[nathaninwa]

Thats how my 2j wired on both the cam and crank along with vr- tied into sensor ground

[shaodome]

Hi Danny,

Running the ground separately will fix your issue. Remember, you may have to switch the polarity on the cam sensor around and change the related edge in the ignition settings (falling or rising). Call me when you get it installed and let me know how it goes!

-Jordan