380,000 mile Prius has mis and shakes/ Help keep her going!

Check this link about PO011 possibilities
http://www.underhoodservice.com/oil-related-engine-codes-vvt-engines/

• Dirty Oil or even wrong oil viscosity
• Variable Valve Timing (VVT) circuit is open or shorted
• Oil Control Valve (OCV) circuit is open or shorted
• Faulty variable valve timing (VVT)
• Faulty oil control valve (OCV)
• Damaged ECM

 

You can pull the vvt solonoid out and test it by putting 12v to it. You will see movement if it's working. I would take it off the car for this test.

Moto G Play ?

 

If you have a scan tool that shows live data, take a look at what your long and short term fuel trims are reading at idle. As close to zero as possible is ideal.

Moto G Play ?

 

There are not a lot of causes of misfires:
1. Ignition timing not right
2. Bad fuel delivery (too much, too little, or bad stream from injectors)
3. Intake or exhaust valves not opening/closing at correct times

As each cylinder has it's own ignition coil and spark plug, and fuel injector, this eliminates numbers 1 and 2 as being likely, as I find it unlikely that these components would fail on 3 cylinders simultaneously. With what TMR wrote, I think it could well be a VVT problem. Other thoughts are the Exhaust gas re-circulation valve/system or the ECU that controls ignition timing.

 

You left one thing that could really must have being the cause of the misfires. Injectors

Have you checked the injectors on the cylinders with reported problems?

If they are clogged with carbon, no matter what you do, the misfires won't go away.

If they checked out fine, do a voltage test on the injector wiring harness connectors to see if they've got power feeding them(I think its 12volt or so), and also do a ground test.

Finally, if the power/ground tests are OK, check for a dedicated 5volt signal wire. If this doesn't have the referenced signal voltage, the ECU gets confused.

If the tests are OK, some of those injectors must have failed already.

A last resort might be the ECU, because it has a dedicated driver that drives the injector pulse of the injectors.

Also check for short circuits along the injector wire harness to the ECU.


Dxta

 

Ah missed this one. I updated my post to reflect this. Clogged up injectors certainly could deliver the right amount of fuel but with bad dispersion in the cylinder; this would cause misfires. On an engine with 300k+ miles, pretty much every component is suspect

 

Also vacuum leaks. That's why a diagnostic plan needs to be established here. Does the OP know how to do they tests is a good start. For the injectors, a balance test is in order. Personally, I always start by looking at fuel trims.

Moto G Play ?

 

I think you approach your diagnostics with two things in mind; VVT System and the misfire issue.

 

You're very correct

 

Were the "coil packs" replaced with actual OEM/Toyota, or something else?

Pretty sure you meant PCV when mentioning the EGR valve, someone please correct me if I'm mistaken.