Yet Another QX56 Timing Issue

[MxRacer527]

This might get long, but please stick with me as I've got a particular issue that I've never seen before... Thanks in advance as I'm new to the forum, and understand I haven't contributed here.

2012 QX56
173k miles

Background on Vehicle
I purchased this vehicle in 2022 with ~135k miles on it when my family began expanding, and it was a dream vehicle for about 35k miles. I towed heavy with it, took it on several road trips, and serviced it as best as I know how. The transmission has shuddered since day one, I changed the fluid and added some shudder fix which helped slightly. I accelerated up a hill one day as it continued to slow down under full throttle, gutted the cats which fixed that issue. That was the last of the simple issues.

Over a year ago, I get the dreaded MIL on the dash for a high pressure fuel p0087 or p0090 I believe. I knew from my research during the catalytic converter issue that I needed to check my HPFP cam, and so I did just that. It looked brand new. So I put a new low pressure fuel pump in it, and the problem resolved.

Took the car on a 1,200 mile trip with the family and my power steering high pressure line started leaking along with a relatively new battery dying when we packed up to leave (not sure if this is relevant to the current issue.)

Soon after returning, my wife went on a trip, and I didn't have time to change the oil so I reluctantly told her to go to have her oil changed before leaving(potential contributor) and she had an event free trip.

Problem
She came home, I had new tires put on, and exactly 132 miles later it went into limp mode on the way home from dinner. Around January 2025. P0021 and P0011. So I pulled the HPFP, and found the cam lobe and lift bucket were grooved. At the time, I figure the vehicle is worth around $5-6k, so not worth paying someone to fix it. I went and bought my wife a Lexus GX460, and accepted my new lawn ornament.

I finally pulled the trigger and dropped $2,500+ on parts from Z1 Offroad(great company to deal with). So over the course of a few weekends I tackled that job, which was a heck of a job for the first time doing it. I've spent a lot of years offroading, wrenching, doing LS swaps, and this was still just a large volume job. Did the whole timing kit from Z1 with oil jets, new HPFP, new lift bucket, new VVT solenoids, all new orings.

First start up I get hit with P0021 and P0011 only when idling. P0300 too I assume from year old gas, and that went away after 200 miles and some fresh gas.

I pulled the new VVT solenoids and checked them with 12V and they are working like they should. I reinstalled them and checked the old ones with 12V and they were working like they should. I then hooked the old solenoids up to the harness while the new ones are installed, and the solenoids are not moving at all. So I checked the plug with a multimeter, and I'm getting 14V to the purple wire, and no signal at all on the ECU wire for either VVT solenoid. Checked continuity from ECU to the solenoids and they are both good.

At this point I don't know how to proceed. I've peeled the harness back to where it crosses behind the intake from each sensor and see nothing visually. However, I did just read in the FSM that if the ECM sees P0021 or P0011 for 5 trips continuously that it will not energize them and go into fail-safe mode.... Maybe I'm chasing my tail. Any advice is appreciated.

[MxRacer527]

I'd also like to add that when I first started it after timing job, I only had P0011. I swapped cam sensors, then got P0021. So I replaced that cam sensor, to which the P0021 never went away. Now I only get P0021.

[VStar650CL]

Did you yank the fuel pump fuse and dry-crank it for awhile before starting it? If not, there's a good chance you jumped the bank2 chain on startup because the tensioners weren't pumped up. You need to stream the cam angles, if the bank2 angle is off from bank1 then your P0021 is from jumping a tooth or two. The cams and tensioners are also on separate oil paths out of the main oil gallery, so if the timing shows normal at idle then it's possible something is blocked or leaking. See LU-6 here:
https://www.nicoclub.com/service-manual ... 2%2FLU.pdf

[MxRacer527]

That is some great feedback. I in fact did not do that. Should be easy enough to fix if that’s the issue. I’ll check that out this weekend and report back!

[MxRacer527]

It jumped time on the crankshaft. thanks for the help

[VStar650CL]