lack of power rebuilt KLZE 1995 MX-3

[RX8SE3P]

Daninksi sorry for being n00b, if I wasn't n00b I would of figured this out lol.

I notice when letting the clutch out slowly the engine will sort of feel unstable like it might stall. It doesn't just go without adding a little tiny bit of throttle, once going it's ok though. My MX6 just goes, you let the clutch out slowly and it has no problem.

Acceleration is not sluggish... like it feels it should have more power lol. There are no flat spots or anything weird it just feels like it should be faster, when you get over 4000 it feels the same, just keeps accelerating but no extra zing to it. The K8 had a nice power surge after 4000, you could feel it was stronger but not the ZE. It's the same all the way to the top.


Now when you say the idle screw, you want me to unscrew it and take the screw out and do some cleaning, or disconnect the IAC or something?

[projectzemx3]

check your vris point one. when the car is off, take the vacuum line off it the little rod so its open then hold your finger over the spot where the vacuum line hooked onto. if the rod stays in then its good, if it comes back out then you need a new one. that could be why it doesnt pick up after 4k. vris point one kicks in at 4200 i believe


my vris goes bwwaaaahhhh!.... not.

[RX8SE3P]

I see, thanks I will check that out.

I just purchased a bunch of stuff off rockauto.com. Got myself a disty cap and rotor as mine are corroded. Am going to get a proper timing light and set it to 10 degrees with the new disty cap and rotor. I think it's out at the moment, which could lead to it being slower I guess.

[projectzemx3]

I see, thanks I will check that out.

I just purchased a bunch of stuff off rockauto.com. Got myself a disty cap and rotor as mine are corroded. Am going to get a proper timing light and set it to 10 degrees with the new disty cap and rotor. I think it's out at the moment, which could lead to it being slower I guess.

that will do it. before this new cap and rotor comes in try turning the distributor, that is how you fine tune the timing, maybe it only need a little advancement.

[Daninski]

Have you tried installing your KL02 VAF from your MX6 onto your MX3. Takes like 10 mins. Then tell me how your engine feels.

[RX8SE3P]

Ok engine was rebuilt, was blowing smoke and being crap, turned out to be bad piston rings letting oil through. Got heads done too. Have driven about 1200kms now on rebuild.

Engine feels even more powerful down low than it did before but as before it feels lacking in high rpms. After 4000 it feels like it's hitting a wall of resistance. It doesn't like it and I don't want to force it. My DE mx6 is completely different, it LOVES getting revved.

I have tried two disty's, tried both a KL02 VAF and stock MX6 ECU and stock KL31 chipped ECU with JE50. Tps would not be causing this much power loss up high and I have tried two of them.

I really need to check codes soon. Could it be fuel pump? The engine is quite nice down low but after about 3500 it feels like it's uneasy and uncomfortable. I'm thinking something to do with fuel. Smells rich, but runs good fuel economy. It's not burning oil anymore though

Does anyone have any theories as to why high rpms are like this?

Oh and I think VRIS is ok, because with the KL31 chip and JE50 it feels powerful down low and crappyish up high but with the MX6 ECU and KL02 it feels slower down low and even crappier up high. So the KL31 chip + JE50 wins so far for power.

Will try a KL02 based KL31 chip soon. See how that goes.

[WhiteFinish]

Your timing could be off.

You don't notice it with your idle etc but you would be missing a lot of power

[RX8SE3P]

Your timing could be off.

You don't notice it with your idle etc but you would be missing a lot of power

Like my physical timing? I don't think we would have gotten it wrong twice but you never know. We did time it with a timing light though.

[onlytrueromeo]

Are you running a ZE manifold or a DE manifold?

What size is your exhaust?

[RX8SE3P]

ZE straight neck, right hand drive
2.25 inch cat back, no cat so that can't be the problem

- Rebuilt heads and block, all new gaskets, seals etc
- Timing would have been done right as it would run crap if it was a few teeth off (runs nice until 3500+ rpms and it just feels gutless after)
- Two disty's tried
- KL02 + MX6 ecu tried
- JE50 + KL31 chip tried
- New intake made recently, no air leaks
- VRIS seems to be functioning, even if it wasn't, it wouldn't make the car feel 30% less powerful than it should
- EGR piped back to itself
- knock sensor was changed to a known working one
- fuel filter changed during swap
- air filter new
- drive shafts new, gearbox changed to mx6
- ARW mounts
- TPS adjusted (tried 2 of them), may need more adjusting but that wouldn't cause so much power loss at high rpms

Only things I am thinking right now are:

Fuel filter may have been faulty???
Perhaps fuel pump is on it's way out, can't hear it on start up
Injectors are bad?

Will check codes but just wondering if anyone has had this issue before or has any sort of ideas?

[RX8SE3P]

On the weekend Stoker100 and I checked the error codes and VRIS. Also checked fuel pressure.

The only codes I got were EGR related and one for the RPC solenoid or something, which I think is the one that goes in between the FPR and air box and back to the IM. This isn't even used on ZE's so there's no major codes unfortunately.

We checked VRIS with Stoker100's eeprom ECU tuner program. Basically, he was able to set the VRIS to open immediately and stay open. We could see the valves physically open. We also cable tied them open and took a run in the car like that. The car felt really crap down low but gained power up high. Still felt the same as before up high but confirmed the VRIS definitely seem to be working.

Checked fuel pressure which was exactly as it should have been.

I revved stoker100's probe up, which has a ZE too. It revs to 4k really quickly at idle. Mine doesn't seem to be that freely revving. Both have lightened MX-3 flywheels too.

I'm almost out of ideas apart from run the car in some more, use thinner oil and get the injectors checked.

All I know is that my MX6 is a good comparison platform and it's waaaay smoother up high and feels like it would win a drag...

[RX8SE3P]

Checked physical timing. No problems there. Such a prick to get down in there and look at timing when engine is in. Oh well I can at least cross it off the list.

Compression tests next I guess. Then dyno. Seriously, if compression is good I have no idea what's going on here. Cursed engine or cursed car? Hmm who knows.

http://users.adam.com.au/kakarot/ze.avi
http://users.adam.com.au/kakarot/de.avi

[RX8SE3P]

EDIT: plug1 and plug2 pics are from my ZE piston 4. plug6 is from another piston on the ZE, all the other plugs look like plug6. Last plug, is from my MX6 de spark plug. I know this engine is running very rich and all the plugs in it look very dark like this (probably only 3000kms old).


So I looked at my spark plugs today after almost 2000kms. All are like the very last pic except for one plug, which looks way darker. It's dry but the rest are like the example pic which is at the bottom.

Does this mean I could be running rich on one injector? I don't want to think it's oil.... but compared to when it was burning oil, it was really wet and shiny jet black. Not sure what to make of it.

[Daninski]

Sorry for not responding sooner. Regarding what I suggested before the idle screw is on the top of the throttle body. Run the engine in diag mode and screw the idle screw in until the engine RPM drops then screw it out to 650 rpm and STOP. If that screw is out too far your engine will have sluggish response.

[RX8SE3P]

It's currently idling at 650 but should I screw it in until it drops reasonably lower, then take it back to 650 or screw it shut till engine almost completely stalls then go back to 650?