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10 votes

How is it advantageous for fuel management to detect negative mass air flow?

There is no such thing as detectable "reversion" airflow to a MAF. Especially on a non turbocharged car. The MAF has no clue about the direction of flow, only how much energy it takes to keep the ...
SteveRacer's user avatar
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5 votes

What is the difference between a MAP and a MAF sensor

Moves.. answer is a good one but you asked about advantages/disadvantages of MAF sensors. Disadvantages are: the sensor sits in the intake and thus restricts airflow. Airflow restrictions translate ...
timbo's user avatar
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5 votes
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Should you replace the MAF sensor housing when replacing the MAF sensor itself?

I wouldn't if there are no obvious defects in the housing. Sometimes parts stores will only sell items as the complete package. When buying a thermostat from oreilly's auto parts for my forenza the ...
Dalton D's user avatar
  • 1,958
5 votes
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1998 V6 Mustang -20+ LTFT on both banks

Cleaning the MAF won't help here because the fuel trims are negative. A dirty MAF would typically under-read mass air flow and subsequently force a positive fuel trim correction. A few possibilities: ...
Zaid's user avatar
  • 39.2k
5 votes

Anyone have experience with a faulty fuel press? Regulator?

Nice engine you got there! While your issues do sound like a MAF problem (check the MAF readings via OBD!), some turbocharged Volvos are notorious for fuel pressure regulator issues. Basically the ...
I have no idea what I'm doing's user avatar
5 votes
Accepted

How do I remove this bolt to replace my MAF sensor?

Just unscrew the nut from the other side and pull the bolt through, the shape of the bolt head is designed to fit into the plastic tabs which will keep the bolt from spinning. If the nut is frozen use ...
GdD's user avatar
  • 17k
4 votes

Is there anyway a shade-tree mechanic can check MAF calibration?

Yes. In fact, since you have a MAF sensor, then you likely do already have the expensive equipment required to perform a calibrated test -- it is called an automobile. The only other tool you will ...
Cognitive Hazard's user avatar
4 votes
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MAF Clamping & Tuning

The MAF is a very accurate flow meter that sits in the intake air path. Its job is to tell the engine how much air is being drawn into the engine, so it can inject the correct amount of fuel to keep ...
Harper - Reinstate Monica's user avatar
3 votes
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Why do modern PCMs prefer MAP over MAF

In the turbo applications I am familiar with, both a wire or film (better) type MAF is used, in conjunction with a MAP, IAT, ECT, etc. Specifically on turbosupercharged Subarus, there's knowledge to ...
SteveRacer's user avatar
  • 12.4k
3 votes

Chevy 2007 Trailblazer Sputtering in the Morning. Code P0171 has come up in the past

Too lean = too little fuel. I would probably try the fuel injector cleaning (Techron or comparable product) first and see if that clears up the issue. Next try swapping the fuel filter since this is ...
Andrew L's user avatar
  • 321
3 votes

How do I remove this bolt to replace my MAF sensor?

Try some penetrant fluid (PB blaster or something else), let it soak for a while. Then hold the round head with some pliers and try to remove the nut. Depending on your luck (and skill) it might be ...
Martin's user avatar
  • 8,458
3 votes
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How to troubleshoot P0101 -- mass air flow?

Yes, the sensor is most likely your problem. Try cleaning your MAF sensor. Use only cleaning solution specified for cleaning the MAF. It is a delicate thing, so be careful with it. If that doesn't ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes
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1996 Ford E350 (5.8L) Mass Air Flow Sensor - where is it?

Well, it turns out that the 1996 Ford E350 doesn't have a Mass Air Flow sensor - hence the trouble finding it :-) Instead, it has a MAP (Manifold Absolute Pressure) sensor, which looks like this: ...
Cullub's user avatar
  • 1,364
2 votes

1996 Ford E350 (5.8L) Mass Air Flow Sensor - where is it?

It should be on or near the air cleaner assembly. It looks like a square thing with a 60 pin connector on it http://www.ford-trucks.com/how-tos/a/ford-f150-f250-how-to-clean-a-faulty-mass-airflow-...
Old_Fossil's user avatar
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2 votes

Check engine lights came up after Air filter change?

Milan, I recommend that you purchase a paper Chilton's or Haynes repair manual for your car. They cost around $30 at your local autoparts store. Many manufacturers have provided a 'secret' code that ...
zipzit's user avatar
  • 6,539
2 votes
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Engine shudders when tachometer falls to idle RPM from around 2K RPM

The MAF supplies air flow and temperature data to the car's computer, a failing MAF sensor can definitely produce surging at idle which is what it sounds like you have. You might also get hesitation ...
GdD's user avatar
  • 17k
2 votes
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open-loop vs closed loop

The engine runs in "open loop" when first started, before the oxygen sensors come up to operating temperature. It basically means the fuel is being metered with MAP/MAF as the primary input. Once ...
agentp's user avatar
  • 318
2 votes

open-loop vs closed loop

Open and closed loop are control algorithms usually coded in the ecu - but to solve your problems apply the tests and look at the results, the code and meaning you show suggest a replacement sensor is ...
Solar Mike's user avatar
  • 34.6k
2 votes

'98 Subaru Legacy Outback -- does this sound like a broken MAF?

Check for disconnected vacuum lines also - there's one that comes to mind which runs from the throttle body to the rear of the engine compartment on the passenger side. Easily knocked off its fixing, ...
PeteCon's user avatar
  • 8,712
2 votes
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'98 Subaru Legacy Outback -- does this sound like a broken MAF?

I can imagine this could be a bad MAF - giving a valid signal (so the ECU does not throw a DTC/CEL) yet corresponding to a wrong air amount. Does this happen no matter what the engine temperature is ...
MaSlo's user avatar
  • 193
2 votes

Engine shudders when tachometer falls to idle RPM from around 2K RPM

So far so good with the MAF cleaning, haven't had the codes pop up for about 850mi post cleaning and the MAF housing's interior and the laminar air screen were definitely dirty. I'm assuming the ...
jxramos's user avatar
  • 1,850
2 votes
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MAF Sensor Performance Code in cold weather

Theoretically, temperature should not affect the operation of the MAF unless it gets very cold (like -40° C or F - take your pick). I'd suggest if you the MAF code keeps popping, even after cleaning, ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes

Is this a right MAF signal?

The MAF should be fine Have a look at this datasheet for the HFM5 series Bosch MAF. It is for a 5-pin MAF (it also measures intake air temperatures) so it's not exactly what you're after, but remains ...
Zaid's user avatar
  • 39.2k
2 votes

MAF Clamping & Tuning

The bottom line is, the MAF doesn't see boost, it sees air flow. The Manifold Absolute Pressure (MAP) sensor can see boost. In most normally aspirated cars, the MAF (if even equipped) and MAP work ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
1 vote
Accepted

Slow acceleration is working, but rapid acceleration is not

I found solution for this problem, it was trivial. Earlier user of this car drove not very dynamic and on low range of engine rpm. I thought that fuel injection map was incorrect, so I reseted ECU ...
rozumir's user avatar
  • 121
1 vote

How come that with a worn MAF and lambda fuel economy suffers but there is no performance gained?

The engine ECU uses the readings from these sensors to get the fuel to burn as weak as possible while still being efficient and keeping the burn temperatures safe for the engine. If the MAF and O2 ...
HandyHowie's user avatar
  • 25.4k
1 vote

2002 Silverado 4.3l wiring question, MAF sensor and water temp sensor throwing intermittent codes

That's usually a break in the wiring harness to the MAF sensor. Pretty common actually. Disconnect electrical connector to MAF. Key in RUN position. Check for battery voltage on Pink wire. If you see ...
user9181's user avatar
  • 1,392
1 vote

1986 Corvette - ECM code 33 & 36

Although not an answer to the code 33 & 36, The Ignition Control Module (ICM) was bad and fixed my no start condition. Tested for more than 45 minutes no problems, no service engine soon (SES) ...
3dalliance's user avatar
1 vote
Accepted

Does the air intake system in a VW CC 2010 go around the engine?

The first part of your description is correct: As I understand it, the air intake is on the front right near the radiator and headlight. It feeds the air in through the air filter, then the maf ...
JPhi1618's user avatar
  • 13.2k
1 vote
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IAT reading higher than ambient temp. Is that normal?

I have a gauge that shows IAT and my car shows the ambient, outside temperature in the gauge cluster. IAT is always higher than ambient. IAT values that you get from the ODB-2 port are coming from ...
Tim Nevins's user avatar
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