Premio 2009 Maf Sensor

[briansmith]

Cause having a rough idle rpm(rpm slow with an slight vibration) went through a tune up, which included fuel system cleaning,throttle body cleaning and checking the plugs. after the job was done during the engine scan test found that the MAF sensor values were too high abt 300% more. No other faults were detected and checked the MAF sensor but it had no dust or any Foreign obects. Car is running well and no other issue with it. Tuning was done at kl**n p**k and they were unable to go further recticifaction other than the basic cleaning. MAF values out of range ,how will it harm? Also no error codes were detected during the scan.

[Rumesh88]

MAF value may have changed slowly over time allowing the ECU time to learn and adjust itself accordingly if the scan data is correct. However, if the value drift is 300% (Is it at idle?) there is a good chance to get a fault code if you keep the rpm around 4000 with full load like when you are climbing a steep hill with 4 adults on board. If the sensor is developing an internal fault over time it will eventually show up as a fault code. BTW did they clean the PCV valve? How many kms the car has done?

[briansmith]

Yes 300% more at Idle rpm. PCV valve was cleaned. Only the throttle body was cleanrd. Also the MAF sensor was checked.

[briansmith]

Car has done around 55000km.

[briansmith]

After observing the car for few days I have noticed the idle rpm remains steady between 600-650 with A/C on on all the gear postions(P,R,N& D). Is this normal to Allions/Premios& Axios ???

[Rumesh88]

I don't think your MAF values are out of range by 300% at any of the throttle positions including idle while the engine is RUNNING. Then you would have got a fault code by now anyway. What Kl**n P**k guys commented on should have been the MAF reading with the ignition is ON but the engine is not running I guess. Ideally this value should be zero for there is no air flow when the engine is OFF, but in practice there is always a residual value. Your rough idle could be due to this but before you decide on the MAF better to get a scan done again from another place to verify this particular value.

[briansmith]

No engine was running on idle and at that moment only the MAF value was 300% higher. After the tune up car has been running more than 1000 kms without any faults. Fuel consumption was slightly reduced. Only issue was rough idle haven't increased. What is the idle rpm with AC on for the premios?

[Aquaman]

Check for broken vacuum lines or loose hoses near teh air intake.

[LancerL]

Try giving a ECU reset by disconnecting positive battery terminal (You may need to reprogram your audio setup) for about 1 hour and reconnect it, start and let the car to run on idle for about 15mins. Make sure A/C and other electronics are not running.

After 15mins take a decent and calm drive about 15-20mins as this will help ECU to relearn new values from all sensors after tuneup (Better keep audio and A/C off until the you finish the drive).

This is something which should be done after every tuneup but unfortunately most of the places don't do this

Hope this will might solve your issue, if not visit someone who is specialized in engine tuning and not a place who only knows to was and vacuum cars.

Edited November 26, 2015 by LancerL

[dhachamila]

Did they clean your Maf sensor? and how did they do tune up did they pull out the all 4 injectors from the engine bay and cleaned (using 3m or whatever inj cleaner) or did they clean injectors without removing? ?? A*W always prefer to pullout injectors and clean for nissans because they said it is the most safest way to do engine tune up because adding chemicals to fuel line and doing injector cleaning is not good (but i'm not sure about whether toyota prefer to add chemiclaes to fuel line)for car and did you check maf wire socket?? Sometimes error codes and rough idel can happen due to poor contacts and after every tuneup ecu should reset.

Edited November 26, 2015 by dhachamila