Loss of power - MX83 Cressida 1JZ VVT-i. Please help!

[JSF]

Hi everyone,

I'm seeking some assistance with my car and to see if anyone else has experienced similar issues and has fixed it and could advise what i should do. My car doesn't feel as fast as it once was, it feels like i've lost a lot of power and i'm not 100% sure what is the problem with it. Some of the symptoms I have are;

- Car's not as fast as it once was.
- Engine is extremely hot, it's radiantly hot as well so you can feel it. A lot of people who have worked on my car have advised the engine is a lot hotter than normal 1JZ VVti's.
- Temperature gauge says it's where it should be in terms of heat. (It's the stock MX83 Cluster temperature gauge).
- The car still pulls and boosts to the correct amount of PSI, but it feels like it's not all there, like a minimal power loss.
- Compression tested the vehicle and the cyclinder closest to the firewall had 140psi.

Mods:
Kinugawa CT15B, Front Mount I/C, 15psi, Stock Ecu, Automatic Transmission MV Shiftkit.

The car has been recently serviced, i check trans fluid, oil and radiator water daily. Thermostat has been changed. My only guess would be that it's a potential water pump issue? My water pump could be old and corroded and my vehicle could be long overdue for a timing belt change/water pump change.

Has anyone replaced their stock cluster temperature gauge with an aftermarket one? I think it could be my water pump failing as it could be old and corroded.

["Z" UTE]

Instead of changing guage clusters, simply install a water temp sender unit from a 7M-GE, that is what the current guage is calibrated to.

Never too early to change a water pump, and a new timing belt with cam and crank seals is the way to go.

[JSF]

Ok so I installed a temp gauge going off the radiator hose. It seems to be getting up to 83 degrees celcius (Alloy Radiator and twin 12" thermos) which is good, So i definitely don't think the engine is running hotter than normal, but it doesn't make sense why the engine feels extremely hot. The car does get hot, however, when i'm drifting it or sitting it on limiter, so that would make me think the water pump is unable to keep up.

[bk_]

AFM reading less air due to aftermarket air filter?

AFR readings?

It could also running less ignition due to knock (less ignition == weaker engine and higher EGTs) although I know on the vvti JZ engines, the OEM ECU will close the throttle by 5% each time when knock is detected, but not so sure if ignition is retarded, too.

Tried an OBD reader? http://www.2jzgarage.com/2013/01/2jz...d-information/

[bk_]

Thermostat has been changed

This is another possibility to explain why it runs hotter.

Incorrectly installed? Wrong part number? Higher opening temperature?

... unless you changed it _after_ the problem!

["Z" UTE]

The car does get hot, however, when i'm drifting it or sitting it on limiter, so that would make me think the water pump is unable to keep up.

DOH 10 characters

[bk_]

Bigger turbo on stock injectors, you cannot do 15psi and >6000 RPM. you're maxing out the injectors.

I've tuned a 2jz vvti with stock injectors and aftermarket turbo. It can't do more than 12psi above 6000 RPM, the duty cycle is already at 90-95% by then.

Did you fill up with a tank of fuel at the track? They're notorious for clogging up injectors, which restrict flow at high RPM.

[JSF]

Sorry, it was having all this symptoms prior to changing anything. What i was meaning in my question was that those are the things i've changed since having these problems. This isn't a track car either, it's just a daily driven car. Daily driven to work. The car previously was running 18psi on a CT15B. I did often mix E85 with 98 but it was about $10 of E85 per $40 of 98/100 Octane fuel. I've tried turning down the boost and things like that, but the problems are still persistent.

[dnegative]

Which rad hose did you put the sensor?
Different, but my 2JZ runs 90-95 according to the sensor in the top hose, cant see a 1JZ running cooler?

I've been told by a few that when you really start to flog the arse out of these things they will go over 100c easily enough but unless its getting properly hot (120), not a major issue.

[mx32vvti]

Hi im looking into doing this swap, I have a jzx100 vvti 1j front sump just need to now what is to do iv looked around and its all over the place

[bk_]

... twin 12" thermos ...

What's controlling the fans? radiator temperature switch? external fan controller with its own temperature sensor?

[1JZ-Rolla]

If you are losing power, but water temps are fine, could be a few things:

Retarded ignition timing - either as a result of a fault in the engine management or a sensor, or being in a diagnostic mode, or actual detonation which would cause the knock control to back off timing
Incorrect cam timing - you may have skipped a tooth on the cam belt, given your claims of limiter bashing May or may not run rough all of the time as a result, but i'd expect you to hear audible difference at idle generally.

Failing that, you really need an AFR gauge in the tailpipe for further diagnosis also.

Out of interest, is the kinugawa the larger upgrade, or just the steel wheeled replacement model?

[JSF]

Kinugawa CT15B has a larger front housing, same size rear turbine wheel, but both front and rear are steel-wheel. The turbo blew on me after 600kms. I'd strongly advise against the Kinugawa and pay an extra $400 to have it highflowed.

[JSF]

What's controlling the fans? radiator temperature switch? external fan controller with its own temperature sensor?

The fans are wired off the ignition, so it's on at full speed as soon as the ignition goes on.

[ARTZ]

running lean due to clogged fuel filter....its happened to me,...a lean engine will run hot

ethanol tends to pick up alot of crap in your tank...if you haven't changed your filter for a while it might be worth a look...I had one with 3000kms on it, could hardly blow through it...

just an idea...