Can anyone share your MAF reading?
Mine VQ30 is around 5 gram/s 1.6 volts at 850rpm idle with AC off

According to FSM it is still in spec, but don't know why both bank LT and ST fuel trim always negative.

Thank you

 

How negative and how old are your front 02 sensors?

 

​​​​​​Thanks for the reply.

Both bank are -11 on long term and around -5 on short term during idle, if acceleration long term will move closer to 0.

I don't know how old the oxygen sensor are, but the car have 187k miles on the clock.

After some live data reading I think my MAF is working fine.

But my idle speed is messed up, after warm up idle speed is around 850rpm and ignition timing at 5°(yeah 5° not 15°)

Already tried idle relearn but not successful, checked everything, no vacuum leak, the car is running fine just not perfect because the fuel trim and higher idle than official spec.

Is it normal that my Closed Throttle Switch always Off???

 

That would be why it's pulling fuel. Timing is too low, so it's nowhere close to burning fully. You're gonna have to figure that out. What's the timing do after idle and under load?

850 is a good idle speed, anyway. That gives you higher oil pressure.

 

Thanks for your reply.
Timing after idle and under load I think is normal, between 10° to 40°. I guess my job now is to bring the idle timing back to 15° first. From what I read the ECU will lower the idle timing when the IACV can't bring down the idle speed, but I'm not sure is it true or not...

850 idle also smoother than 700.

 

Well, just found out my fuel pressure regulator has small amount of fuel leaking from vacuum port, also the same thing happen on fuel pressure damper but it's worst than the FPR....

 

That would make sense for the rich trims. Let us know if it fixes it.

 

Interesting.... What's with the timing, though...