MR2/Celica hybrid engine conversion/swop

[GrumpyYoungMan]

This is my first post here, so please be gentle!

The project:
Patient: MY2000 1.8 MR2
Donor: MY2004 1.8 Celica

2000 MR2 1.8 Engine swop burning oil…

So, I have a MY2000 MR2 which was excessively burning oil, so I tried to be clever, and use a bottom end out of a MY2004 Celica, I have transferred all the MR2 components to the Celica bottom end (Cylinder head, cams, etc) the problem I have now is the compressions are over specification, and it misfires and glows the catalyst for cylinders 2 and 3…
Compressions are
1: 215psi (14.8 bar)
2: 200psi (13.8bar)
3: 190psi (13.1bar)
4: 200psi (13.8bar)

I have rechecked the engine timing, and the valve clearances are all within specification

I am out of ideas as before the conversion the engines were running perfectly… so is the stroke/pistons different look the same to the naked eye?

[BYRNEY1984]

Is the celica engine the same 1zz-fed as in the MR2 or could it be the 1zz-fe or even the 2zz 190bhp engine.
But seems odd as to why your compression results are the way they are. Low compression in a cylinder can be a whole manner of things but high compression is an odd one.

[GrumpyYoungMan]

Is the celica engine the same 1zz-fed as in the MR2 or could it be the 1zz-fe or even the 2zz 190bhp engine.
But seems odd as to why your compression results are the way they are. Low compression in a cylinder can be a whole manner of things but high compression is an odd one.

According to the specification they are the same!

Celica VII (T23) 1.8 VVT-i (1ZZ-FE) 2000 - 2006

Engine
Code: 1ZZ-FE
Capacity: 1794 (cc)
Distribution type: Timing chain
Engine speed at maximum power: 6400 (rpm)
Number of cylinders: 4

MR2 (W3) 1.8 16V (1ZZ-FE) 2000 - 2007

Engine
Code: 1ZZ-FE
Capacity: 1794 (cc)
Distribution type: Timing chain
Engine speed at maximum power: 6400 (rpm)
Number of cylinders: 4

I wonder if the 1ZZ-FED makes all the difference?

And yes, hunting a low compression is totally far easier... :/

EDIT: Sorry it looks like this has originally been posted in the wrong forum!

[jimi]

Why did you split the engines ? If the Celica engine was OK would have seemed sensible not to mess with it, other than the ancillaries that were different.
This thread (and a couple that are linked to it) may provide more info on any differences https://www.spyderchat.com/threads/engi ... 05.147522/

[GrumpyYoungMan]

Why did you split the engines ? If the Celica engine was OK would have seemed sensible not to mess with it, other than the ancillaries that were different.
This thread (and a couple that are linked to it) may provide more info on any differences https://www.spyderchat.com/threads/engi ... 05.147522/

That is a very good question, but the engines were spilt due to the differences in cooling system layout, probably caused by the different engine locations?

The MR2 has a oil cooler pipe feed located under the inlet manifold from the cylinder head to the oil cooler…

I’m beginning to wonder if the cylinder head/pistons are slightly different shapes/sizes…

[BYRNEY1984]

There is a difference between the intake valves,the fed engine found in the Mr2 are 1mm bigger than the fe
You will need to find the stroke lengths to be sure they are the same.
I wonder if it is a timing issue. But then surely the valves would be hit the piston. Think you will have to pull the engine and start again. As annoying as that is. One thing I can think of is is the injector for that cylinder dumping fuel in there, or is the head not sealed to the block properly causing oil or coolant to be in the bore. This would raise compression. Beyond that its a tear it apart and see.

[GrumpyYoungMan]

There is a difference between the intake valves,the fed engine found in the Mr2 are 1mm bigger than the fe
You will need to find the stroke lengths to be sure they are the same.
I wonder if it is a timing issue. But then surely the valves would be hit the piston. Think you will have to pull the engine and start again. As annoying as that is. One thing I can think of is is the injector for that cylinder dumping fuel in there, or is the head not sealed to the block properly causing oil or coolant to be in the bore. This would raise compression. Beyond that its a tear it apart and see.

You are on the same page as me.

Engine timing is correct; I have already checked that, I have also checked the valve clearances.

It is only the Celica block, pistons, etc… so the cylinder head is the original MR2 one.

All new parts were the same between the two engines, I checked all that, timing chain, cylinder head gasket, etc…

The compression test was carried out with all spark plugs removed, but now I come to think of it the coolant expansion tank has been refitted, but if compression pressure was entering the cooling system I’ll expect to see a water leak?!

[BYRNEY1984]

Try swapping the injectors around and see if it runs better. But I don’t think the petrol would cause it to raise compression. Plus when you do the compression test the plug and cylinder would be stinking of fuel. Must be a coolant or oil issue.

[GrumpyYoungMan]

Try swapping the injectors around and see if it runs better. But I don’t think the petrol would cause it to raise compression. Plus when you do the compression test the plug and cylinder would be stinking of fuel. Must be a coolant or oil issue.

If anything I would say it’s lean.

It’s also logging codes P0300 through to P0304 so it’s effecting all cylinders which is why I checked the compressions… and the MIL light is flashing. forgot to mention that on my opening post…

[BYRNEY1984]

Ah right. Are you 100% of the timing. Because if its retarded too much that would make the manifold glow cherry red. Something I had to deal with on my 3vz turbo. But thats using a dizzy. Not COP. But still why is one cylinder high. Without anything running.

[GrumpyYoungMan]

Interestingly enough the high compression is cylinder # 1, but the catalyst that is glowing is cylinders 2 and 3…

My setup has 3 catalyst; one for cylinder 1 and 4 and one for 2 and 3 and then a main catalyst.

Maybe I should check to see what all the lambda sensors are reading, before I remove the engine again?

[BYRNEY1984]

I would stop the engine from firing and crank it over. Then pull the plugs and see what the cylinders have in then.

[GrumpyYoungMan]

I would stop the engine from firing and crank it over. Then pull the plugs and see what the cylinders have in then.

I will try that…

So you don’t think it’s a man made problem by using the Celica block with the MR2 head?

[BYRNEY1984]

Well something is a miss if both engines were taken out running. Just a case of ruling out the easiest ones before pulling it all apart again.