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Dalahare
11-08-2005, 02:24 AM
Hi All, I'm new here, Look foward to chatting Mods and other things in the future, but for now I was hoping someone here would be able to help me with some problems my KR verada has been having.

A little background on the car, auto 3l v6, 92 model sedan, 130000ks, has dealer services in the book untill 80,000ks, dunno what's been done to it between then and 120,000ks when I bought it. It's had services as per the manual since then, I don't think the timing belt has been done, I will get it done shortly. fuel injectors have been cleaned at some stage, as it's obvious they have beeen removed from the car due to the markings on them. Always run on premium.

The are a few problems, but imainly awful fuel consumption and awful responce from the motor.

Consumption is up to around 18L/100ks, Throttle responce is extremely poor,there is not much difference between 1/4 throttle and 3/4 throttle at low revs, then at about 2700rpm you can feel a sudden improvement in the power delivery, so if you hold the throttle half way down, it will be sluggish untill 27000rpm where it will then accalarate at pace I presume it's meant to perform at all the time.
Up slight slopes under constant throttle, when under that magical 27000rpm mark, you can hear the engine note changing, like the fuelling is being changed, despite me not doing anything with the throttle and speed remaining the same.

I have taken it to mitsubishi, and asked them to check for fault codes, presuming that the o2 sensor, TPS or airflow meter might be playing up, but said it showed no fault codes at all, and suggested they remove the CPU and send it to melbourne for testing, $200 odd just to test it, with no guaranteed result, and me being without a car for about 2 weeks, and i'd hate to think what they would try to charge for a new CPU.

Has anyoe else had similar problems with sluggish v6's? what was done to fix it?

Other problems it has are:
if there is less than half a tank of fuel in it, It will stall around left hand corners if driven hard so it's producing high g forces, Is this a common problem, and I just need to keep the tank filled up, or do you think that the fuel pump/pickup in my car might be faulty?

And the last is with the auto, It changes gear on it's own accord, it will kick down gears by itself, sometimes even when just coasting down a hill with the foot completely off the accalerator, I took it to a shop to try and get it fixed, but when the guy drove it he said he wouldn't try to fix it untill the sluggish motor was fixed, as I would be flooring it so often to get past the sluggishness that it's probably confusing the auto.


Thanks for any help, Rick.

Mitsiman
11-08-2005, 08:34 AM
It could be a number of things and although you had no errors pop up I would start with some basics.

Firstly of all TPS switch - get a new one cause if that is not working properly / not set properly it affects idle, acceleration and the auto transmission and the way it changes gears.

Secondly replace the O2 sensor anyway. They only have a life of aroudn 60,000km and is the number one cause of bad fuel economy and bad running. THis will not bring up an error code if it is just not reading accuratly.

Lastly go back to basics have yuo got the right spark plugs, replace them anyway and check yoru ignition leads and distributor cap for corrosion, rotor button and ignition timing.

If all else fails and no differnce, time to pop it onto a dyno, get a air/fuel ratio check and see whats exactly is happening.

Dalahare
11-08-2005, 09:56 AM
I've replaced the leads and plugs, but haven't looked at the rotor cap or button, will check them out, I'll stick in a new o2 sensor as well, if it's still doing these things then i'll replase the TPS switch as you say, but that one i'm unsure about, where do I find it and what does it look like, I presume it's attached to the thottle body?

Mitsiman
11-08-2005, 10:10 AM
Yes the TPS switch is the unit attached to the throttle body opposite the throttle cable.

Dalahare
11-08-2005, 10:42 PM
Went to repco this arvo, $125 for the o2 sensor, $240 odd for the tps, sound about right? anywhere in sydney to get these bits cheaper?

Killbilly
12-08-2005, 06:44 AM
I wonder if the TPS just isn't set right? That might help out.

If you're mechanically minded you might want to give this a go, it worked wonders for me:

ADJUSTMENT OF IDLE POSITION SWITCH AND
THROTTLE POSITION SENSOR (TPS)
(1) Disconnect the throttle position sensor connector.

(2) Using jumper wires, connect an ohmmeter across terminal
3 (idle position switch) and terminal 4 (sensor ground) of
the throttle position sensor.

(3) Insert a 0.65-mm-thick feeler gauge between the fixed SAS
and throttle lever.

(4) Loosen the throttle position sensor mounting bolts and turn
the TPS body fully counterclockwise.

(5) In this condition, check that there is continuity across
terminals 3 and 4.

(6) Slowly turn the throttle position sensor clockwise until you
find a point at which there is no continuity across terminals
3 and 4. Then, tighten the throttle position sensor
mounting bolt securely.

(7) Connect the throttle position sensor connector.

(8) When using the multi-use tester, connect it to the diagnosis connector.

(9) When not using the multi-use tester, proceed as follows:
*Disconnect the throttle position sensor connectors and
connect the special tool, Test Harness Set, between
the disconnected connectors.
*Connect a digital voltmeter between the throttle position
sensor terminal 2 (sensor output) and teminal 4 (sensor ground).

(lO)Turn the ignition switch ON (but do not start the engine).

(11) Check the throttle position sensor output voltage.
When using the multi-use tester, select item No. 14 and
read the throttle position sensor output voltage.
Standard value: 400 - 1,000 mV

(12)lf the voltage is out of specification, check the throttle
position sensor and associated harnesses.

(13)Remove the feeler gauge.

(14)Turn the ignition switch OFF.


ADJUSTMENT OF FIXED SAS

(A) The fixed SAS has been factory-adjusted. Never attempt to
move it.

(B) Should it be out of proper adjustment, adjust by following
the procedure given below.

(1) Sufficiently slacken the accelerator cable.

(2) Loosen the lock nut on the fixed SAS.

(3) Sufficiently loosen the fixed SAS by turning it counterclockwise
to fully close the throttle valve.

(4) Tighten the fixed SAS slowly to find a point at which it
contacts the throttle lever (where the throttle valve starts
opening). From that point, tighten the fixed SAS further 1 l/4
turns.

(5) Holding the fixed SAS to prevent it from turning, tighten the
lock nut securely.

(6) Adjust the accelerator cable tension.

(7) Adjust the basic idle speed.

(8) Adjust the idle position switch and throttle position sensor
(TPS).