MAF Sensor

ferocity02 · Post by **ferocity02** » 13 Jan 2020, 00:43

For my 1998 S70 I'm looking to replace the MAF sensor hoping it correct a misfire issue. I've tried just about everything else.

The OEM unit is around $300, and I read that there can be lots of issues with non-OEM brands.

Is there a cheaper alternative?

I believe the PN is 1275749.

Post by **misha** » 13 Jan 2020, 01:55

Bosch part# 0 280 217 107.
https://www.ebay.com/itm/Fits-Volvo-850 ... SwRD5eF5Hn

What you can try is to drive a car with MAF sensor's connector disconnected.
If it runs better without it,you found the culprit.

ferocity02 · Post by **ferocity02** » 13 Jan 2020, 12:05

misha wrote: 13 Jan 2020, 01:55 Bosch part# 0 280 217 107.
https://www.ebay.com/itm/Fits-Volvo-850 ... SwRD5eF5Hn

What you can try is to drive a car with MAF sensor's connector disconnected.
If it runs better without it,you found the culprit.

Wouldn't it run much worse without the MAF plugged in? I've left it unplugged on accident before and it ran like dog shit, would barely idle.

Post by **misha** » 13 Jan 2020, 13:23

Assuming that MAF is bad,the car will run better when it's disconnected(it's for testing purpose only).

If MAF is good and car runs good....it wil run worse when you disconnect it.

With MAF disconnected,car will go into limp mode but it would run.

rasense · Post by **rasense** » 13 Jan 2020, 13:35

I believe that I have a good OEM MAF from a 98. PM me if you are interested.

Post by **misha** » 13 Jan 2020, 13:50

When MAF is bad the car would ALWAYS run rich(black smoke from the exhaust followed with high unburnt fuel smell-raw fuel).
The car would run like c*ap.
The rpm would bounce up & down on idle.
Sometimes the car wouldn't even start...depending on how it fails.

But....i never heard that bad MAF would cause a misfire.
I would check ignition components(cap & rotor,spark plugs and wires),vacuum leaks,fuel pressure and fuel delivery....fuel pump relay also.

ferocity02 · Post by **ferocity02** » 13 Jan 2020, 16:57

misha wrote: 13 Jan 2020, 13:50 But....i never heard that bad MAF would cause a misfire.
I would check ignition components(cap & rotor,spark plugs and wires),vacuum leaks,fuel pressure and fuel delivery....fuel pump relay also.

I've been chasing this misfire for awhile and have replaced everything that I can think of that would cause a misfire, something I even replaced wire (e.g. the entire ignition system).

My thought was that if the MAF sensor is reporting air flow incorrectly that the engine may be receiving too much or too little fuel causing a misfire under heavy load. It's the stock sensor with 205k miles on it, I figure a new sensor would be well received either way.

Post by **misha** » 13 Jan 2020, 17:03

GLT...LPT or n/a?
Ignition components replaced...oem?
Cap & rotor must be Bosch,wires Bougicord,spark plugs correctly gapped cheap copper ones or Volvo spark plugs.

If misfire occurs only on heavy load at WOT it could be the lack of fuel delivery or the engine is running lean which...again....is lack of fuel or too much air(vacuum leak).

ferocity02 · Post by **ferocity02** » 13 Jan 2020, 17:59

misha wrote: 13 Jan 2020, 17:03 GLT...LPT or n/a?
Ignition components replaced...oem?
Cap & rotor must be Bosch,wires Bougicord,spark plugs correctly gapped cheap copper ones or Volvo spark plugs.

If misfire occurs only on heavy load at WOT it could be the lack of fuel delivery or the engine is running lean which...again....is lack of fuel or too much air(vacuum leak).

It's a GLT.
I try to only use OEM parts, so the ignition is all the good brands you listed.
I need to do a boost/leak test of the intake system and compression test. It could also be a bad injector.

Post by **misha** » 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.