P0340.....help

Im just concerned that maybe chain is off a tooth but if interference engine then I would think that would be noticeable. The truck has no power but other then that starts and idles great. You can drive it although gutless.

 

Yes the 2rz and 3rz is an interference motor, I can't say for certain but i would assume you'd have a bent valve even if it was only 1 tooth off..

Is this your first time behind the wheel of tacoma with the 3rz? These trucks are notoriously gutless, my older Toyota with the 22re felt like it had more pep than my current 3rz.. and when I rebuilt it I bored out the cylinders, bored out the throttle body and installed bigger injectors and it still feels gutless

Toyota greatly improved the timing chain aspect of the 3rz compared to the 22re. My 22re needed a timing chain and you know it because you could hear quite the slapping noise because the guides were worn out. I would assume if the 3rz had similar wear you'd hear the chain slapping first


It's not too much of a task to take the valve cover off and the spark plug out of the first cyl and check timing just for your piece of mind.. if you've had this issue since you bought from the previous owner It's possible he didn't preload the split gear and maybe that's one of your gremlins? If it is something that has come since you bought it though im going to suspect something different.

You may need to do a resistance check from the sensor to the PCM... maybe corrosion in the harness is causing the sensor to read in sync? I'm purely speculating because I really want you to be able to figure this out lol I have a weird desire to keep every 3rz alive

 

I would for sure be down to check/verify the timing. Shop wanted to do it but it was 200.00 and this is my daughters project. I'm sure the 3rz is gutless compared to my other vehicles but I do have a 230 flathead dodge that can get up to 70mph and this truck is struggling to get to 50. It feels as though its missing about half the power it should have. Is the a timing verification procedure somewhere? Someone have a manual or guide? Also if the gear isn't preloaded correctly is that easily rectified? Does whole front cover need to come off like changing the chain?

 

The waveforms are off significantly which is a good sign that the timing needs to be checked. Could be assembly, could be crappy aftermarket components. Worth a look while youre in there to see where the sensor is reading off the cam and see if it is different from an OEM cam. Something just doesn't add up with this one.

 

My Short Observation is that you have a timing issue.
-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/

My long observation is it’s a timing issue.

I’m by no means a mechanic, this is just my observation.
And none of this could be right.

Before we start let’s make clear, we are talking about rotational timing, NOT IGNITION TIMING.

Looking at the diagram, and knowing the crankshaft gear has 34 teeth and generates 34 signal per revolution. Plus a “space” of almost 2 signals gives us 36 signal. Which coincides with 360 degrees
nicely. That gives us 10* between each crank signal peak.

Remember the crank gear only has 34 teeth, so the distance between each tooth is roughly 10.5* of timing.



The camshaft gear generates 1 signal per revolution.
The Camshaft peak on the good wave is roughly 20* AFTER the starting peak of the Crankshaft.

Your wave shows roughly 20 BEFORE the start of the Crankshaft peak.
That’s a difference of about 40*. Or roughly 3.8 teeth on the crankshaft.

This indicates to me the following

1.Jumped camshaft teeth
2. Stretched Timing Chain
3. Sensors or ECM

I’m going with a combination of 1 & 2

For your sake, let’s hope that the crank sensor is bad.
Even though it does look like it sees the correct 34 forms.

 

I dont think we are going to change crankshaft sensor...we are going to pull the valve cover and take a look at everything. It won't be for few weeks though as we have stuff going on.

 

Over a year later we finally made time to dive in...starters, found the previous owner installed an LCI balancer shift delete kit. Install looks correct...pulling the diff out to remove oil pan was a pain. After market axles are installed with a 41mm spindle nut not the factory 35mm that everything everywhere lists...

Anyway, tensioner still had some room left on it and although chain was used I don't think it was that stretched...the chain was however 4 teeth off alignment on the crank gear....there is the problem obviously...lol


We are still in install currently because the crankshaft position sensor bolts broke off in timing cover so have to get those out before we reassemble.

 

roll her over by hand to verify that there isn't any interference.

 

We did turn it over a few times after chain on correctly and nothing sounds off or bad. Gonna di it again before I close up timing cover. The crank sensor bolts broke in timing cover so going to friends shop today to get them out and hopefully button this thing up tonight or tomorrow. Will report back

 

While I have this thing open...anyone have any other tips/advice for checking things inside? Any kind of preload on cams or weird stuff special to 3rz? Just don't want to open it right back up if I can help it.

 

Sounds like you found the issue. Good job. My only suggestion from this point is to take as many pictures as you can while it’s open. If you haven’t put on the timing cover yet, do you mind sharing a photo? I’d like to see what was done prior to your ownership.

 

Not sure what to take pictures of. We have some poor quality images of before but this is new chain and tensioner and guides installed and engine turned over few times.

 

You mentioned you turned it over a few times. Did you turn it over and see if it was still timed correctly after turning it by hand?

Alignment marks, lobes, chain, woodruff key, literally everything you won’t be able to see when you close it up.

 

Yeah everything looked good. We run into another problem after getting timing cover and oil pan all buttoned up. Qent to torque the crankshaft pulley and the woodruff key seems to have shattered or shifted. Can't tell from the perspective we have without pulling stuff off but can't get the crank pulley fully seated.

 

You tried to torque it without seating the pulley first?

 

Update...timing chain all fixed and engine codes all clear. Runs great. Starts great. No leaks...wonderful to have this behind us. Ran into new california issue but ill make new post maybe some people can help with...