2UZ Fe Help - Multiple misfires after both heads/timing belt replacements

[Dino2007]

Hello forum,
I had a bad intake valve on bank two and had p0171, 174, very large short and long fuel trims, after driving a bit with engine losing power, so I replaced both heads with rebuilt heads purchased off Clearwater Cylinder Heads, also timing belt/pump, spark plugs, injectors, front catalytic converters and minor items. I keep getting multiple misfires on both sides on start. There is also a some noise from either valves or injectors and very noisy engine. I've double checked the timing belt, removed everything up to the new heads and inspected. It seems everything is aligned (dots on cams, crankshaft, timing marks). The cams are torqued to spec and turn, and engine turns as well. Where do I start diagnosing the issue? So far multiple days spent and I am pretty upset looking at the possibility of engine replacement now.

 

[TheBussman]

what brand are the injectors spark plugs and cats? how long have you driven it since the work was done? have you reset the adaptions? what are your adaptions now? any codes now?

 

[Dino2007]

what brand are the injectors spark plugs and cats? how long have you driven it since the work was done? have you reset the adaptions? what are your adaptions now? any codes now?

Injectors - OEM denso, I actually have 2 sets, original and refreshed, tried both, sparks -OEM denso, cats are - Toyota/Lexus OEM for VVTI.

I haven't been driving since doing work, since the engine is malfunctioning.

I haven't reset any adaptations - not sure what they are. The codes are P0 300, 301, 302, 303, 306, 308 now, but others were misfiring just prior

Before that 3 days ago, I had P2135 Throttle Pedal Position Sensor Switch A/B , and P0123. I took everything apart and put another throttle body from another GX470, which seems to fix the codes. These codes didn't come back.

 

[TheBussman]

First i would take a vacuum gauge reading, if that is less then 19" or bouncing then compression test and then if any of the cyls are low perform a leak down test. if everything is good there check valve lash. if all that is good take a dollar bill and put it on your tail pipe, see if it get sucked into tail pipe when it misfires (if it does your have an exhaust valve leak) I know you just put reman heads on but: I don't have any experience with that company, I've seen a lot of messed up machine work on heads, also I've seen good heads get valves bent in shipping before. I've also set valve lash on the bench before, then bolted the head onto the block, start it up, had misfires and the issues was the the lash changed slightly because the head gets slightly distorted when the head bolts are tightened and it was enough to change the lash .002" and that's enough for a misfire sometimes.

 

[Dino2007]

First i would take a vacuum gauge reading

Where would I connect the gauge on 2uzfe?

 

[TheBussman]

any port on the intake manifold, unplug the evap hose and use that would prob be the easiest.

with regard to noise: did you tension the cam gears with the service bolt, install the cams and then remember to take the service bolt back out?

 

[Dino2007]

with regard to noise: did you tension the cam gears with the service bolt, install the cams and then remember to take the service bolt back out?

One the R side yes I had the bolt, on the L side, I forgot, and I had to tension the spring to insert the bolt later, when reinstalling cams, teeth on the exhaust cams were 100% aligned after turning crank to tension the belt, not a single mm apart. ofc the bolts were removed.

I ordered the vacuum gauge, but in the meantime I did a quick compression test.

Cyl1 and it's zero. The rest of the driver side is 160 or so.

Cylinder 6 is zero. Cylinder 8 is 180, Cylinder 4 is 155, Cylinder 2 is 160 or so.

What would be the next steps? Does it sound like I had broken the heads on the first startup?

Also I did compression tests before starting all work, and all was at around 160-180psi.

Should I run the leak down test now?

 

[TheBussman]

yes i would run the leak down test on the 0 cyls. listen to where the air is coming out.

 

[Dino2007]

yes i would run the leak down test on the 0 cyls. listen to where the air is coming out.

Performed the ldt on cylinder 1 as it was easy to TDC with timing marks. It's leaking out of the throttle body intake at a high rate. I need to research the best way to tdc cylinder 6. If you can give a hint, which tools to use for that I'd greatly appreciate it.

So on cyl 1 the leak is so huge that the leak gauge is at zero and the left gauge is letting air out at the rate of around 15psi per minute or so. What would be the next step on L cylinder head then?

 

[Dino2007]

I think I found tdc for cyl 6. Initially It was all the way up, as was cyl 1 at tdc (confirmed with t markings) so I measured depth with a metal rod for #1, marked with tape, then inserted the rod in cyl 6 and rotated crank until it disappeared and reappeared again now at tdc. Cyl 1 would be at top too but not tdc.

 

[Dino2007]

yes i would run the leak down test on the 0 cyls. listen to where the air is coming out.

Same thing on Cyl 6. Air coming out of throttle body intake when #6 in tdc for this cyl. Also I rotated the crank back to TDC#1 and checked cyl 6 now the air was coming out of both intake and exaust. Intake should have been sealed in that position for #6.

So what are the next steps now? See also 2 messages above.

 

[TheBussman]

need to take the heads back off and see if the intake valves are bent or stuck open in the guides.

 

[Dino2007]

.

 

[Dino2007]

need to take the heads back off and see if the intake valves are bent or stuck open in the guides.

Will take em off during the weekend and ask how to inspect. In the meantime do you see any correlation in that, that the opposite cylinders having the issue. I.e. #1 is at the tdc power stroke, #6 is at the exhaust stroke.

 

[TheBussman]

if you accidentally bent them during install then maybe. doesn't really matter at this point. you can inspect the pistons for contact when you get it open.

leave the spark plugs in the heads, turn them upsidedown and fill each combustion chamber with washer fluid. you'll be able to see the washer fluid leak of the leaking valves.

 

[Bisho]

You may consider pulling the valve covers and looking at the offending valves and cams and see what's happening before you pull the heads.

 

[nissanh]

You can use a borescope to inspect the valves at the compression stroke.

 

[awesomeissquid]

Use a wood dowel as you rotate the engine by hand to identify the TDC.

 

[Dino2007]

You may consider pulling the valve covers and looking at the offending valves and cams and see what's happening before you pull the heads.

I'll take a pic once covers are off, then take the cams off and take more pics.

 

[lelandEOD]

What was the resolution on this?