The MR2 Owner's Club of New Zealand

stag wrote:Any new updates available at this stage? Keen to see this on the road soon.

You and me both

Beginnings of cleaning up under the hood.

Removing power steering gear to fit non-power steer rack.
Removing ABS unit to fit non-ABS lines. (Have damaged the sensor wires to the rear, have tried fixing them with no luck so figured it would be easiest to remove.)
Also while under here removing the remainders of the Aircon lines.

Sourcing a new battery this week to install and begin working on the tune.

Might need a bit of a clean up before reinstalling battery etc as it is a bit rusty around where all these components fit in. Just surface rust from sitting debris.

Some swag from Zebra parts:

-Steering Intermediate shaft to finish off the manual steering rack conversion.
-Full conversion for wind-up windows
-DIN slot cup holders

And a new battery which was much needed.

Looks good man. Such progress, many wow

More good progress tonight.

After attempting to fit the manual steering intermediate shaft I realised that the universal joint off the power steering rack did not fit the manual steering rack (larger diameter on the power steering input shaft). So shot back to Zebra to pick up the last piece of the puzzle.

Got all this in and tested the steering to make sure there was no funny noises, all good!

Gave it all a quick clean and coat of paint to tidy it up a bit before reinstalling the battery box and new battery.

Looks much better now, although the battery clamp I have does not fit correctly, another thing to add to the list.

Tomorrow night will be re-install front calipers and attach the rack ends to the hubs. Will be interesting to see if the manual rack ends are the same as the power assisted ones...

Have fitted the wind-up windows. They work a treat and the doorcards tidied up pretty well. The drivers seat armrest is a little saggy. May have to look into how best to fix this at some point.
Was pleasantly surprised to find that there is no difference in the doors between the wind up and power window models, the wind ups bolted straight in to different positions than where the power windows were mounted.
Also spent 5mins to tidy up the panel where the ECU is as per the picture below.
Went through the wiring diagram and removed the 80A fuse for Power steering and ABS so the main power for each of these won't short at the plugs. Still taped up each plug from the removed units

Went to update the ECU however I confirmed it is already running the latest firmware. As a test of why it is running so crap I tried to load my first tune that was supplied with the ECU, however this made no change as to how it ran and idled. So as this used to be better there must be something wrong with the engine itself causing the misfire and general poor running.

Basically where the engine is at now:

Constant misfiring. From what I can tell all injectors and spark plugs are working. As I can feel each injector pulsing and I had checked the plugs/leads earlier. Although I will recheck these to make certain that they are ok.

The 02 sensor is taking readings from the front bank of cylinders which is giving a reading of between 10.5 and 12 air fuel ratio. Which seems very rich for just idle.

At this stage without further opinions I plan to get a compression tester on payday to check that it hasn't done a headgasket/warped the head.

I know the engine is mis-firing and it's a WIP, but holy crap this car sounds good.
I had the privilege of hearing it over the weekend and it sounds like a beast

So after getting a compression tester a few days ago I sat down to do it tonight.
This was the first time I've done the test and given that the engine was still cold and I had no helper, I hope the results are accurate enough. I let it crank 6 times for each test and both passes were dry runs.
The results were as follows (In PSI):

Cylinder Pass 1 Pass 2
1 183 180
2 215 228
3 178 186
4 210 215
5 185 205
6 220 220

So my question is, why is there such a big difference between the banks? And does it matter?
From what I've read the results look OK.

I also noted that all the spark plugs from the front cylinder had carbon build up on them, and this would ring true to what I was seeing on the AFM (Running Rich), although the rear bank cylinder spark plugs looked normal. I'm not sure what could cause the front bank to run richer than the rear.

At the end of the Compression test, the piece that goes on the end of the tester decided to get stuck in the cylinder. It took me bloody ages to get the POS out.
In the end I managed to get it out by wrapping insulation tape around the thread of a spark plug, wind it in tight and then hope like hell it stuck.

I guess it's possible that the carbon build up might bump the compression numbers up a little on one bank.

How is your O2 sensors setup? do you have one per bank?

If you are getting all your O2 readings from just one bank, and a cylinder was running poorly (rich), the other bank could end up lean. Could either be injector related (one clogged or leaking), or poor spark on one of the cylinders (bad leads, distributor cap?). Maybe even a vacuum leak effecting only one bank?

Just to clarify - you don't have adjustable cam gears or anything like that?

I'm not that familiar with the V6 banks but could a cam belt issue cause that compression problem? Just thinking about the Subaru boxer design and clanking valves on one side which can sometimes be attributed to a worn belt.

The carbon buildup on the spark plugs was on cylinders 1-3-5 so the cylinders with lower compression numbers.
I only have one 02 sensor reading the AFR from the front bank (1-3-5). The loom for this makes it difficult to wire to a position that has both banks, or even wire to the rear bank and maintain a gauge in a visible spot in the cabin. I didn't really want to splice into the factory supplied loom for the gauge.

I do not have adjustable cam gears. And the cambelt positioning was spot on last time I checked. Although I'm thinking it probably wouldn't hurt to pull the top cover off to check anyway.

I'm not sure that the Megasquirt will run 1 bank leaner/richer than the other? But I could be wrong.

Do you think if there was 1 bad injector/lead that it would cause the whole bank to run rich/lean?

Benckj wrote:I'm not that familiar with the V6 banks but could a cam belt issue cause that compression problem? Just thinking about the Subaru boxer design and clanking valves on one side which can sometimes be attributed to a worn belt.

The belt has only done about 700kms from brand new, I should hope its not worn! Although it could have slipped....SO I should probably check it again before continuing.

The belt has only done about 700kms from brand new,

Would be beneficial to check as if off by a tooth or maybe the wrong belt used, one bank would run rich and have less compression.

I don't think it would be an injection or ignition (EMS) problem as that would not result in low compression. Same goes for O2 sensor or AFM problems. Look for something mechanical which would cause lower compression which is either rings, valves or HG.

Essdub is very knowledgable with these engines. Maybe flick him a PM with some questions. I'm sure he would be happy to help.

Benckj wrote:

The belt has only done about 700kms from brand new,

Would be beneficial to check as if off by a tooth or maybe the wrong belt used, one bank would run rich and have less compression.

I don't think it would be an injection or ignition (EMS) problem as that would not result in low compression. Same goes for O2 sensor or AFM problems. Look for something mechanical which would cause lower compression which is either rings, valves or HG.

Essdub is very knowledgable with these engines. Maybe flick him a PM with some questions. I'm sure he would be happy to help.

I've re-seated the valves, new rings and .025 over sized pistons, and new headgaskets at same time as the cambelt. No AFM and ECU is not getting closed loop feedback from the O2 sensor.
When first run it was OK but had other issues, wouldn't rev over 3.5k rpm but was good at low rpm. After changing the ECU it would run great hot but would not start cold...etc etc. So this would suggest it WAS the correct belt. Whether it may have stretched or slipped is another story so I will definitely check that, thanks for talking it through.
If this is not an issue, then I guess I will have to pull the front head off and check for warpage or damaged HG. Are the compression values outside of spec though? I read that if they are within 70% of the max value this is OK. But I don't trust my engine with the misinformation that goes around online. There is no sign of water in the oil/oil in the water.

If I have to pull the heads I think I will be putting head studs in this time around.

With a helping hand I managed to check quite a bit last night.

Removed the top cambelt cover (a lot easier than a 3s one!) and double checked that the cambelt and cam pulleys were aligned correctly to the crank. They were.

Checked resistances on spark plug leads and injectors. They all appeared normal as per the table of results below: Checked spark plugs for spark and found that one in bank 1 was problematic. It appeared to be sparking between the central electrode and the insulator. Can't say I have seen that before but definitely deserving of the bin. So will be replacing all 6 again come payday and fingers crossed she runs better.

That No 5 lead resistance seems rather low as compared to the others. Nothing you mentioned makes any sense to why the lower compression in Bank 1. Guess if you throw new plugs into it and it goes OK that will be end of story?