My 2001 Toyota Mark II Grande, Engine TA-JZX110, Automatic Transmission, 2.5ltr engine has been stalling and reflecting the check engine light, and showing two codes on diagnostic machine :
VVTi System Malfunction code. TCV (Timing Control Valve) code
I realized one day that the fuel economy was getting bad, at around 130000km mileage. I am not quite sure, but I think I also had a stall or two IN MOTION. It also was idling rough. Since I bought it second hand from Japan, I assumed the time for spark plug changes was up. I replaced these plugs with exactly the same brand, type and part number as the old ones.
Now the problem has not gone away.
When I started after the spark plug changes, the car improved tremendously in terms of accelaration response, and the idle was consitent. I drove to fill up the tank about 2km, and I realised the rough idle was back. Eventually, it stalled and failed to turn-over UNLESS I did so with the foot on the gas pedal. Temperature gauge was normal.
After an hour, and having used the diagnostic machine showing the codes above, I checked the Variable Valve Timing Control Solenoid, and tested with a multimeter, the resistance was 8.5. I then applied a small voltage and it wouldn't open and move as it should. I tapped it a bit to manually move it, and when I applied the DC voltage again, it started moving (opening and closing).
I put the Variable Valve Timing Control Solenoid back, and when i cranked again, it turn smoothly just liked when i started. The Engine oil is about 6months old, but less than 1000km old.
After a short drive again, this happened all over again, and I took off the solenoid again, moved it and plugged it back in, the car turns.
The solenoid is a little expensive, so I would want to be sure before replacing, could this be:
- Bad Oil?