Hi !
I have just rebiult my 3sgte gen3 mr2 turbo.
New cp pistons,rods,bearings and full gasket set.
The engine head is also repaird valves and full gasket set.

Before the rebuilding i had just problem with CO on 2500rpms.
But now I have high CO ,CO on 2500rpm ,HC AND lamda.
I have a new catalysator (100cell).

Don´t know what the problem is !
Have cleaned the whole trottlehouse.
But the engine is still running 1020rpm with out pulling the gaspedal.
The lamdba is 1,07 .
Look likes it is a vacuumleak somewere but can´t get it I have a mapsensor so if it would leak it will probebly be the injector gaskets or the intakemanifold gasket wich is new.

Help!!
Don´t know what to look for anymore!
/ Dennis -sorry for my bad english but i hope you understand me any way (Im swedish)

Hi Denni

Can you tell us what model car you have please

Your recoded lambda value points towards the Lambda sensor being faulty

There's a good post (written by me of course ) on how to check it but briefly:-

Locate the OX pin in the diagnostic connector box
From cold start the car and monitor the voltage on the OX pin

You should see around 0.8V while the car is warming for the first few minutes. This voltage should then sudenly drop to around 0.5V when the car warms up a little


//PS
If you think your English is bad you should hear my Sweedish Bork Bork Bork

HI ! and thanx for answering !
It is a mr2 turbo gen3 the same as celica ST205 . Modelyear 1995 .

And i have checked to put E1 to TE1 to check codes but i don´t have any!
AND the lamda (oxygensensor) is new.

It's worth checking the OX port on the diagnostic connector

It's possible you have a wiring issue somewhere. If it's failing on Lambda emissions when tested it has to be an issue with that circuit. Closed loop the ECU should compensate for most things within reason. It would seem yours does not

Have search your post about to locate the ox pin and so on but can´t find it.
Anyway. The oxygensensor is new so it can´t be broken allredy.
The CO tell´s me that it plenty of petrol in the mixture but the rmp (1020rpm then the engine is worm) tell´s me that it is a vacuum leak somwere.
So i tryed to spray some "starting gas" on the inlet manifold and around the trottle but nothing happends!
Tryed to clean the mapsensor with som crc spray but nothing happend .
I have 1500rpm then it´s cold as normal.
The engine drives normaly also.
But you can hear some "boff boff" from the exhaust then not pulling the gaspedal.
AND i can´t find any damage on the hoses or nothing so it´s not possible that the are leaking.
The engine works very good before the rebuilding it had lamda 1,00 before. But i had som noise from the engine and it was "piston-knock"
so I had to rebore it and put som new pistons in it from cp.