FZJ80 Rough Idle / Misfire P0300, P0303 & P0304

[BILT4ME]

Photos below. Thoughts on the ridge?

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The ridges are only an issue if you're going to remove the pistons because the rings won't pull up past the ridge to get the pistons out.

If the head is within tolerance for flatness, why is he going to shave it?

Install the head with a new OEM or Cometic gasket, new head bolts, and get on with it.

The extra gap at the top of the cylinder from the ring ridge may cause a slight loss of compression and a bit of oil usage, but I've seen worse. I'm talking minor amounts.

If budget is an issue, I'd put it back together and run it.

Just make sure he understands the proper head bolt tightening sequence.

 

[landtank]

I’ve posted this on one of the engine threads, might be this one. Techs who don’t know read the torque spec and gloss over the 2 quarter turns when installing the head. With this guy saying they were loose, that’s likely the case.

 

[rdcnj]

I’ve posted this on one of the engine threads, might be this one. Techs who don’t know read the torque spec and gloss over the 2 quarter turns when installing the head. With this guy saying they were loose, that’s likely the case.

God forbid they sat down to read once in a while and did things as if it were their own vehicle.

 

[rdcnj]

This looks porous / degraded and may be a cause for concern long term.

I would ensure you have a compression and leak down test with photo/video verified results on all cylinders when they are completed.

 

[txoil]

Thanks Malleus, Landtank and rdcnj. I think he wants the head to be perfectly flat, not just within tolerance. I have asked him for specs on current flatness/skew and to confirm stud tightening routine.

 

[txoil]

This looks porous / degraded and may be a cause for concern long term.

I would ensure you have a compression and leak down test with photo/video verified results on all cylinders when they are completed.

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What min psi would you think is acceptable on such a leak down test?

 

[Malleus]

Thanks Malleus, Landtank and rdcnj. I think he wants the head to be perfectly flat, not just within tolerance. I have asked him for specs on current flatness/skew and to confirm stud tightening routine.

FWIW, there is no such thing as "perfectly flat", only "as flat as my measuring tools can determine". The tolerance exists because testing has enabled Toyota to determine the permissible flatness required to obtain a seal. You can pay for more, but you won't get any benefit.

 

[powderpig]

The only way to truly tell how much of a ridge is on the cylinder wall is to clean the carbon off the cylinder wall(as well as the piston). This to me is part of HG job, and always has been. What is this talk about if the piston rings were replaced or not?? he bring that up?

I clean the carbon off the cylinder wall(and piston top) with solvent and scotch rite pads. If the carbon is thick, I use steel bristle brushes(small ones).

Only then can you truly make a good determination with the proper tools to measure the surface of either the head or the block.
what does that surface of the head look like? Got a picture of it to post?? I would be interested in seeing that surface.

The videos are interesting, this guy (tech??). the top of the block needs to be cleaned and measured, not just guess at the "check mark" between cylinders. It may be reading .002 or .003. or some other measurement (once you know that, a good choice can be made). Hell it =could be heat discoloration of that area where the gasket was no longer.

What scares me is lack of cleaning. I personally would never show a customer the garbage inside the engine he is showing. Vaccums and air keep it all some what clean. I would be worried that it was not cleaned properly .

I find it interesting this guy is not measuring and just feeling these items and guessing.

The pictures of the carbon and the light ring groove I do see is appropriate for the miles you have not he engine. Again, the top of the block needs to be cleaned up and
a straight edge need to used to measure to get good info to make good choices. AS well as the carbon off the cylinder walls.

I would also request pictures or a short video of the top of the block and cylinder bores before the head goes on to make sure it is all clean before the head
goes on.

 

[txoil]

The only way to truly tell how much of a ridge is on the cylinder wall is to clean the carbon off the cylinder wall(as well as the piston). This to me is part of HG job, and always has been. What is this talk about if the piston rings were replaced or not?? he bring that up?

I clean the carbon off the cylinder wall(and piston top) with solvent and scotch rite pads. If the carbon is thick, I use steel bristle brushes(small ones).

Only then can you truly make a good determination with the proper tools to measure the surface of either the head or the block.
what does that surface of the head look like? Got a picture of it to post?? I would be interested in seeing that surface.

The videos are interesting, this guy (tech??). the top of the block needs to be cleaned and measured, not just guess at the "check mark" between cylinders. It may be reading .002 or .003. or some other measurement (once you know that, a good choice can be made). Hell it =could be heat discoloration of that area where the gasket was no longer.

What scares me is lack of cleaning. I personally would never show a customer the garbage inside the engine he is showing. Vaccums and air keep it all some what clean. I would be worried that it was not cleaned properly .

I find it interesting this guy is not measuring and just feeling these items and guessing.

The pictures of the carbon and the light ring groove I do see is appropriate for the miles you have not he engine. Again, the top of the block needs to be cleaned up and
a straight edge need to used to measure to get good info to make good choices. AS well as the carbon off the cylinder walls.

I would also request pictures or a short video of the top of the block and cylinder bores before the head goes on to make sure it is all clean before the head
goes on.

Powderpig, I appreciate your thoughts and insight. Here’s a video showing the underside of the head unit. Thoughts?

 

[txoil]

The only way to truly tell how much of a ridge is on the cylinder wall is to clean the carbon off the cylinder wall(as well as the piston). This to me is part of HG job, and always has been. What is this talk about if the piston rings were replaced or not?? he bring that up?

I clean the carbon off the cylinder wall(and piston top) with solvent and scotch rite pads. If the carbon is thick, I use steel bristle brushes(small ones).

Only then can you truly make a good determination with the proper tools to measure the surface of either the head or the block.
what does that surface of the head look like? Got a picture of it to post?? I would be interested in seeing that surface.

The videos are interesting, this guy (tech??). the top of the block needs to be cleaned and measured, not just guess at the "check mark" between cylinders. It may be reading .002 or .003. or some other measurement (once you know that, a good choice can be made). Hell it =could be heat discoloration of that area where the gasket was no longer.

What scares me is lack of cleaning. I personally would never show a customer the garbage inside the engine he is showing. Vaccums and air keep it all some what clean. I would be worried that it was not cleaned properly .

I find it interesting this guy is not measuring and just feeling these items and guessing.

The pictures of the carbon and the light ring groove I do see is appropriate for the miles you have not he engine. Again, the top of the block needs to be cleaned up and
a straight edge need to used to measure to get good info to make good choices. AS well as the carbon off the cylinder walls.

I would also request pictures or a short video of the top of the block and cylinder bores before the head goes on to make sure it is all clean before the head
goes on.

Just Re-read this. I will ask the shop to clean off the carbon from inside the cylinders. Thanks.

 

[rdcnj]

What min psi would you think is acceptable on such a leak down test?

You generally don't want to see a large variation from cylinder to cylinder, when doing a leak down test.

ie; if 3 cylinders have 5 psi loss and 3 have 15 psi, that's a cause for concern. I believe the general rule of thumb is 10% variation.

So if you're putting 80psi of pressure, you don't want to see more than 10% loss across any one cylinder (8psi).

The tighter the spread, the better sealed the engine is.

We just did a compression test (different then a leak down) on the reman engine assembly and the specs achieved were:

Cyl #1: 182psi
Cyl #2: 187psi
Cyl #3: 182psi
Cyl #4: 181psi
Cyl #5: 187psi
Cyl #6: 198psi

We performed an incylinder test (which helps determine leakage of psi) and based on the compression test and incylinder test, we decided the leak down test would not be needed in this scenario.

 

[txoil]

Another update, folks. Shop says parts are almost in to put head back on in 2 wks or so. He had told me this before but now is asking if I’d like the engine wire harness replaced. Said the injector wires were glued on when he got the truck, the knock sensor plugs are all cracked up, and harness near EGR melted.

Path now appears so new harness for $1k or he glues back on the old one and I replace harness myself afterward or get someone to do it. Wit’End seems to sell Toyota for $676 new.

As always, your thoughts are much appreciated. Thanks.

JC

 

[Fj80oregon]

You can buy a harness from partsouq for under $500 shipped to you. If you buy from Witt’s end it might take a couple months.

 

[txoil]

Thank y’all for your worthy advice these past months. The shop finally finished and I picked up the truck. Shop claimed they cleaned everything up and did what I asked. Engine runs smoothly except now there’s a vibration when in D or R and the brake is on but goes away with even slight lifting of vehicle and unloading of suspension. Will discuss on a different thread.

Thanks again, I’m blessed to be part of such a knowledgeable community!

 

[alia176]

I read the whole thing, and learned a ton. Thanks fellas!!