MAF Sensor

Post by **abscate** » 14 Jan 2020, 06:53

You will faulting lean codes if you are getting t\oo much air , or if the MAF

Have- a look at the fuel trims and see what your engine is trying to correct, that will guide to you to the fault.

Finding vacuum leaks is much easier when you KNOW you have them.

Post by **SonicAdventure** » 14 Jan 2020, 15:16

LOL speaking of MAFs...1996 non turbo 850 wagon -

Went out for a Sunday drive a few days ago. About 20 miles from my house; I decided not to bring my phone.

Stopped at a gas station for gas, got some coffee, come out and the car would not idle right AT ALL. Up and down, revving, chugging the whole bit. Stalled several times also. Got it going again and pulled from the gas pump to the side of the station where I was out of the way. Let it sit a minute, thinking maybe I was having recurring issues with my fuel pump or relay. Disconnected battery and swapped out my fuel pump relay just to see. Sure enough, it started right up, but then it stalled again. This time, it threw a code: P0102 low MAF voltage. I unplugged the MAF cable and it sort of started OK, ran crappy for about 10 seconds then stalled. Next time I started it up it seemed to run OK.

Didn't really want to make the trip, but I said my prayer and gave it a shot...I figured every mile I got closer to home was a few bucks off the tow bill, but I would have been walking to the nearest farmhouse to make the phone call. Car made it home no issues, although the idle didn't seem 100% even. Let it sit overnight and the next day I swapped the MAF with the one from my old 98 n/a which never threw a MAF code. Car started right up and has been running fine since.

Not sure what throws the low voltage or if that can be "cleaned" away. Any way, if there is a way to repair this aspect of these sensors I would be willing to try.

Best of luck everyone -

Sonic

ToriWhite · Post by **ToriWhite** » 15 Jan 2020, 13:13

At least before swapping MAF ($300!!!) its worth giving it a shot with some MAF cleaner.. you never know!

Post by **SonicAdventure** » 16 Jan 2020, 14:02

ToriWhite wrote: 15 Jan 2020, 13:13 At least before swapping MAF ($300!!!) its worth giving it a shot with some MAF cleaner.. you never know!

The part I swapped came from out of a parts bin; removed from my old car last summer. I saved the one that "failed" and I may test it someday, but for now I shelved it.

Post by **erikv11** » 16 Jan 2020, 14:23

Get a junkyard MAF, $20-30, makes it really cheap and easy to troubleshoot or bail you out if the existing one fails. Must be Bosch for 98 and earlier.

ferocity02 · Post by **ferocity02** » 16 Jan 2020, 20:31

misha wrote: 14 Jan 2020, 02:04 What spark plugs the car have?
Volvo plugs or something else?
Spark plug gap is critical on turbo cars.
They don't like fancy plugs....just Volvo ones for turbo engines or cheap copper plugs(NGK or Bosch) properly gapped.

It has cheap copper plugs. I cannot recall the PN or set gap, so I bought some Bosch 9755 plugs and will ensure they are gapped to 0.028".

ferocity02 · Post by **ferocity02** » 18 Feb 2020, 15:16

misha wrote: 14 Jan 2020, 02:04 What spark plugs the car have?
Volvo plugs or something else?
Spark plug gap is critical on turbo cars.
They don't like fancy plugs....just Volvo ones for turbo engines or cheap copper plugs(NGK or Bosch) properly gapped.

It was indeed the plugs. I replaced them with Bosch 7955 FR7DC+ gapped to 0.028" and misfire seems to be gone.

I will not be replacing the MAF sensor at this time.

Post by **misha** » 18 Feb 2020, 15:52

Seems to be gone or gone?