1994 1mzfe lacks power... - Toyota Nation Forum : Toyota Car and Truck Forums

***lemegacool*** · 05-01-2010, 07:14 PM

hi guys!

ok... so i have an automatic 94camry with the 1mzfe and i got a lack of power issue...

i searched this forum with the keyword i had in mind and found out about the knock sensor thread from eye8pussies, i'll get back to that

first of all i'm going to describe the problem and tell you what i've looked at...

when the car is cold-warm i have HORRIBLE acceleration from a dead stop... when the car heats up i gain some power but again from a dead stop i have shitty acceleration... and overall i feel like the car lost power from when i first got it...

-spark plugs has been changed (stupid rear bank!)
-trans oil was changed (15liter)
-injectors were cleaned using the aluminium canister plugged to an air compressor...
-throttle body was cleaned
-cone air filter cleaned
-compression is about 155 psi
-fuel pump puts out about 35-38 psi
- vacuum is at about -22hg
-no check engine light
-plugged a snap-on scanner and all parameters looks ok (injector trim and blablabla) no misfire on any cyl
-did a stall test and engine locks at 2500rpm
-fuel comes out of the filter very clean (anyway i got another bnib one to install)
- coils are on spec... haynes manual says .5 to .85 ohm and they are reading .8ohm
-no exhaust backpressure
-throttle body position sensor is reading 70% open when at WOT i've been told that its not that important and to leave it alone... WTF! to me it looks kinda important!?!
-while having the pedal to the floor the engine then engine accelerates slowly then at 4000 rpm it changes sound and accell harder (i kinda found out it was due to a valve opening in the plenum to allow more air...)

i was looking at eye8pussies's dyno graph before he moved the knock sensor and it looks VERY simillar to the one i obtained from my ipod touch...

look at the first graph on his thread

http://www.toyotanation.com/forum/t158255.html

and look at my graphs

looks like i got something going on no?

thanks for reading my loooooooong post

bigbird · 05-01-2010, 07:47 PM

have you checked the IAC valve?

any codes?

***lemegacool*** · 05-01-2010, 09:34 PM

no codes at all... IAC... is this the one that is on the end of the plenum? if so it work... it opens at about 4000 rpm

chronoti · 05-02-2010, 10:53 AM

idle air control, it's on the tb area, 02 sensors?? if you cleaned all that up and you have no knock codes look at the o2 sensor.

well check how tight your tb cables are that can clean up that 70%

and now are you running premium like the manual says you should for maximum performance?

time since last ecu reset?

***lemegacool*** · 05-02-2010, 11:48 AM

Quote:

Originally Posted by chronoti

idle air control, it's on the tb area, 02 sensors?? if you cleaned all that up and you have no knock codes look at the o2 sensor.

well check how tight your tb cables are that can clean up that 70%

and now are you running premium like the manual says you should for maximum performance?

time since last ecu reset?

O2 sensors are ok the scanner was giving good readings
cables are tight... When the pedal is to the floor the throttle body is physically opening to 100%
yes i run premium fuel..

Ecu reset ?? Never Heard of That... :s

chronoti · 05-02-2010, 11:59 AM

pull the efi fuse under the hood for 15 seconds (or remove the battery) the ecu dumps everything and relearns

i could say all that winterized fuel up there might of skewed the ecu maps so a relearn might do some good

***lemegacool*** · 05-02-2010, 12:03 PM

Quote:

Originally Posted by chronoti

pull the efi fuse under the hood for 15 seconds (or remove the battery) the ecu dumps everything and relearns

i could say all that winterized fuel up there might of skewed the ecu maps so a relearn might do some good

thanks! i'll give it a shot...

okok by iac i thought he meant intake air control... i higly doubt the idle control valve is kaput... but i'll check it using the test socket... te1-e1

edit: just did the test using the te1 and e1 test points and according to the haynes manual the idle speed is supposed to go up for 5 seconds... Mine seemed to actually slow down... To test the valve should i just take it out and apply direct 12v to it and Check for operation?

Re-edit: i just jammed 12v to the valve and i clearly hear it open...

Btw thanks for the help so far!

93celicaconv · 05-02-2010, 07:49 PM

Just noted your compression values. The 1MZ-FE compression pressure, per the service manual, should be:

Compression Pressure: 178 psi or more
Minimum Pressure: 142 psi
Difference Between Each Cylinder: 14 psi or less

I would say your compression pressure of 155 psi, and you didn't say what each cylinder was, so I will assume they are all uniform, is really pretty low. I'm not sure you are going to get much more out of that engine, by the compression pressure values you obtained.

carsrus · 05-02-2010, 08:08 PM

Are you sure the cat isnt clogged? Is it burning/smoking oil out the exhaust?

chronoti · 05-02-2010, 08:45 PM

Quote:

Originally Posted by 93celicaconv

Just noted your compression values. The 1MZ-FE compression pressure, per the service manual, should be:

Compression Pressure: 178 psi or more
Minimum Pressure: 142 psi
Difference Between Each Cylinder: 14 psi or less

I would say your compression pressure of 155 psi, and you didn't say what each cylinder was, so I will assume they are all uniform, is really pretty low. I'm not sure you are going to get much more out of that engine, by the compression pressure values you obtained.

seafoam may help with this mainly if it caused by poor seal on the valves ... you know ... just saying

***lemegacool*** · 05-03-2010, 05:56 AM

Yeah compression is pretty uniform...
Did a exhaust backpressure test and there was no restriction. No smoke at all

i guess i could try seafoam... if its leaking from the valves i could lap tbe seats...
The engine has 190000 km btw

73sport · 05-03-2010, 11:01 AM

We seem to be putting the 1MZ under a microscope looking for something they once had but seems lost at the moment - power and potential.

Take a look here, some of the same footsteps are being taken on 95.

2, 4, 6, All lean, Why? Need Help!
2, 4, 6, All lean, Why? Need Help!

This title may better reflect the current condition.
1MZ doesn't Gettie-Up; Why? Need Help!

The 155psi cylinder pressures seem real low as said above, so you might wana take a closer look at your gauge or try it again if its been awhile. Drop some oil in the bores after doing the test once and see if it changes it. It'll give you insight as to RINGS or Valves whereby no changes after adding oil points to valves and if the compression rises = rings. You need to add the same amount of oil to all cylinders, and if done all at once, the last cylinder done could have pushed the "oil out" so it may read lower than the others for that reason alone.

Does yours ever come to life or is the response just flat all the time? Mine plays about - showing its potential, then hiding it keeping me guessing as to the root cause? Because it can spring to life, I vote mine does not have a plugged cat. Your's, you might want to crack the exhaust open ahead of the cat and see if it changes anything as I'm not sure what test you did that eliminates exhaust flow from the equation??? Care to explain?

Good Luck

73sport · 05-03-2010, 11:18 AM

Quote:

Originally Posted by chronoti

well check how tight your tb cables are that can clean up that 70%

FWIW: Throttle Position Angle as reported by software only reaches 74% and that is within spec.

Also, take a look through this it has diagnostic troubleshooting as well as a full range of values expected from hardware. . . EG2.pdf is the one (1MZ-FE Engine (V6))!

http://www.camrystuff.com/index.php?page=Gen3_Manuals
Toyota Gen3 (1992-1996) Camry Repair Manuals

Thanks to Jeeves @ ToyotaNation.com and RacingSouthwest.com

General Information:

Mk3 Camry/ES300 Repair Manual

Air Conditioning System (2.59MB)
A140E Automatic Transaxle (4.47MB)
A541E Automatic Transaxle - V6 Automatic Tansmission (4.76MB)
Body Electrical System (7.98MB)
Body (5.61MB)
Brake System (12.64MB)
Charging System (2.05MB)
Clutch (636KB)
5S-FE Engine (I4) (18.00MB)
1MZ-FE Engine (V6) (24.92MB)
Ignition System (2.05MB)
Introduction (1.50MB)
Maintenance (1.26MB)
Manual Transaxle (3.17MB)
Supplemental Restraint System - Air Bags (4.76MB)
Suspension and Axle (3.98MB)
Steering (2.74MB)
Starting System (1.66MB)

Entire Mk3 Camry Repair Manual: CamryRepairManual.rar (110.50MB)

Lexus Specific

***lemegacool*** · 05-03-2010, 04:38 PM

mine does the same thing sometime hiding its potential then unleashing it... weird

btw thanks for all the info up^^ i'll be sure to check this out...

when i'll have the time i'll check compression again and i'll try the oil trick...

the exhaust test i did is using a exhaust backpressure gauge

edit: currently reading you post... near identical as mine exept i dont get misfires... i lack power seriously when cold... and when i changed the plugs about a month ago the rear bank was black-ish color so not lean right?

93celicaconv · 05-03-2010, 06:37 PM

Quote:

Originally Posted by lemegacool

edit: currently reading you post... near identical as mine exept i dont get misfires... i lack power seriously when cold... and when i changed the plugs about a month ago the rear bank was black-ish color so not lean right?

The blackish color on the tips of the spark plugs either indicate running rich, and/or oil getting into the cylinders and being burned.

There are so many potential causes for "lack of power" on an engine - it would be best to get live data from the engine upon startup to see what that data is telling you (and to compare it to live data from when the engine is warm, to draw a comparison).