Take a mirror and look all over your intakereonator box. It has a heat shield on bottom. It’s before the throttle body so depending on where you smoked test it would be isolated. Its AFTER MAF so if it is cracked around seam (guarantee it is) the maf does accounts for bypassed air. Smoke test from air filter to throttle body.

 

Is it true. A fairly common place in 2JZ for a crack to appear. I replaced the resonator box with a new one because mine was previously cracked and someone glued it along the seam at the bottom.

 

Only components I replaced on engine. Resonator box. Accelerator pedal position sensor and signal wires to coils One time had bad misfire. Chased for week. In end spark plug wire appeared pressed all the way in coil but wasn’t. Obd 2 indicated multiple misfired. It was only 1 cylinder computer not smart enough to identify cylinder

 

I took the heat shield off any looked over the resonator. It's good.

 

TPS readings are at about 17% without a foot on the pedal. When starting the car they fluctuate maybe one percent, but the car dies so quickly it's hard to get more than a few frames of data.

Here's where the timing all lines up:

 

I recently tested the VVT-i solenoid (oil control valve), which is located above the intake camshaft gear. Toyota TechStream has an electronic function to test the VVT-i solenoid ON / OFF when the engine is idling. And if it's fully engaged, the engine will stutter and die every time I've done it. They even notify you about this before the test.

Could your VVT-i solenoid be mechanically stuck in the fully ON state, regardless of power applied?
You can remove it and briefly apply 12V DC to the coil to check if the spool moves inside the valve body.

 

Tested the OCV with +12V and it does actuate. Also tested the throttle control motor and it's working. Still at a loss here. Maybe I need to go back and check fuel pressure again.

 

Well, attach a pressure gauge to the fuel injector rail for a while. When troubleshooting, just a quick look at the gauge needle will tell you whether the fuel pressure is OK.

 

Car is back up and running. No check engine lights, however it still hesitates at higher RPM (2500+). I've been driving it around with a fuel gauge hooked up and has not exceeded 22 PSI at any time. Generally it is at 18-20 PSI. Service manual calls for 44-50 PSI. The pump is good and I've tried two separate fuel pump computers. No change. Perhaps it's time to replace the fuel pressure regulator?

 

Fuel pressure regulator and pay close attention to O-Rings / grommets / rubber cushion in that fuel pump/filter/pressure regulator assembly.

 

Well, I replaced the fuel pressure regulator (just the regulator, metal part) not the full assembly. In-line fuel pressure tester literally reads 0 PSI when the car is running and has been there for the last week. If I press the bleed-off on the gauge a little bit of gas dribbles out. The car runs and drives. I put 100 miles on it last night. The only real issue is continued stumbling if I try to do a pull from 0 up to 60 and go beyond 2500 RPM. What would be the possible cause of zero pressure at the fuel rail? I know there is not a clog between the pump and the rail, that's been tested. Tested multiple filters.

I believe there is some sort of bypass, maybe that is stuck open and the pump is working overtime to just dump fuel back into the tank? Is that the plastic part in this picture?

 

When repairing a fuel pump, you must use all new O-rings, grommets, rubber bushings, etc. This is the most common source of failure. Assembly is very complex: the fuel pump outlet must fit snugly against the fuel filter with a bushing in between while the outer housing holds them aligned together. This also applies to the pressure regulator assembly.

 

Change the coilpacks, oem Denso, nothing else, trust me. Amazon has them. Oem Toyota Iridium plugs. And change the coilpack connector, those wires start issues as well.

 

I just can't see the issue being the coil packs. I switched them around among the cylinders and also replaced the plugs to no avail. Seems like if the plugs or the ignition coils were the issue it would persist at all operating conditions rather than the car only stuttering when placed under rapid heavy load or when attempting a pull at higher RPM from cruising speed. To me that still indicates that fuel pressure is the issue. I just don't understand how I'm still seeing 0 PSI on the fuel pressure gauge at the rail even though I've replaced every single part of the fuel pump assembly. My last try was to just replace it with a junkyard assembly and that still didn't change anything. Car drives great under mild load or a little higher load upon first starting and then won't accelerate past 2200-2500 RPM if it's been cruising (using more fuel). The check engine light flashes until I back off the accelerator for about 10-15 seconds then kicks off and the car runs perfectly normal at 1600-2100 RPM.

Any ideas what I'm missing with the fuel system - or is this a symptom of poor ignition performance (plugs or wires). I've tested those parts and don't want to drop $300 on OE ignition coils when the existing parts are in spec.

 

Did you do engine leak down test?