Quote:
Originally Posted by DrRobin
5 point Torx arrived, but won’t get enough grip on the bolts, both are rusty, so I had to drill them out. Fortunately I found a couple of screws that are almost the correct size, so they will do until I get some new bolts.
The MAF looked reasonably clean, just a small amount of dust on the sensor, cleaned off and left to stand.
I put it back in and after the engine was warm MAF reads 4.2g/s at idle, same as before. I took it for a drive, 100% better, probably about the same as it was with the MAF disconnected.
My short term fuel trims settled down to around 0%, long term on bank 1 is -0.78, but bank 2 is -3.91. I suspect this might pull back towards zero after a few more miles, but given it felt smoother I am not going to worry. I will try to get a few miles on over the next days.
Intake air temperature was 20C, actual air temperature is 9C, I guess the intake gets a bit f heat from the engine when warm.
I think I will buy a new MAF, now that I know it’s part number and hopefully that is it.
Robin
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Sounds like the MAF was the issue.
Dirt even so small and fine that you can not see it can have an effect on the MAF.
They are very sensitive. Another thing that happens with them is that very fine dirt particles erode the coating on the hot wire. You can't see it with the naked eye. I have seen magnified pictures of the issue. Looks just like it had been sand blasted.
Yes Intake Air Temp. is affected by engine temp.
If your short term fuel trims stay at or near 0% they will eventually pull long term fuel trims down.
I think you stated you have 93k miles on the car.
MAF signals tend to slow down with age.
A new MAF "may" give you better throttle response and fuel mileage.