testing MAF

[Iggy flywheel]

well I think I have an answer for my poor gas milage. I tested my MAF today. Haynes manual volts

0.5 to 0.7 at idle
1.5 to 3.0 increased RPM

my results
0.78 idle
1.48 raised RPM

This looks like it is out of specs and I need a new MAF. Could this cause my gas mileage to go down after I change the plugs? Can this cause pinging as well?

Would it be better since I need new one to go with a bigger aftermarket MAF? I been looking at the ProFlow MAF not to bad price 204.00 compared to dealer. Ford seems to have a problem with the MAF for explorer from what I have read........

Any thought would be helpful before I spend the dough........

 

[jimmiecakes]

I would try cleaning the MAF, first. What type and heat range of plugs did you use and what did YOU gap them to?

 

[Iggy flywheel]

I have cleaned MAF before think it was this summer. I use Autolites and gapped them what is called for 0.54

 

[jimmiecakes]

OK.... so far, so good from the sound of it. MAFs have been known to go south on these, though for .02 of a volt I'd be inclined to see if there may be other causes.

The MAF (Mass Air Flow sensor) tells the computer how much air is entering the motor allowing it to adjust fuel volume. The MAF is kind of like the "boss" and the O2 is used only for fine tuning the mixture.

Even though your check engine light isn't illuminated, it may serve you well to have your ECM scanned for continuous codes to help diagnose the problem.

I've used Autolites in the past and have had very little in the way of problems with them. Of worthy note, even one heat range off can create similar problems. I always cringe when a partsperson uses the cross reference rather than the application chart. If your problems surfaced only after the plug replacement, I'd have to recheck that stuff before I went further afield.

 

[Skohler]

Ok then, I have a question for you. My CEL light is not on, but I ran a code scanner and came up with MAF low voltage. I am getting poor gas mileage and have changed out the O2 sensors within the last 3 months. Would a good cleaning clear up the MAF or is this something that probably need replacement? If I do clean in, what is the best way?

Thanks
Steve

 

[Iggy flywheel]

Well to clean the MAF you can do a search on that. Pull the cap off that the wires plug into. There is a coiled wires. Spray o2 safe carb clean on them let dry put back together. At proflow Mass they talk about cleaning the screen with windex but I not clear on this method. It recalibrates it. The oil from KMM filters forms on the screen. Iam not sure if this will correct the volt problem but it worth a try. Also since you have a low volt code may need to test it in driving mode. There are 3 test for volts idle, raised rpm, and driving.

 

[Robert]

Originally posted by Iggy flywheel
well I think I have an answer for my poor gas milage. I tested my MAF today. Haynes manual volts

0.5 to 0.7 at idle
1.5 to 3.0 increased RPM

my results
0.78 idle
1.48 raised RPM . . .

Your increased RPM voltage should cover the range, depending on your RPM. If all you got out of yours was 1.48 V regardless of how high your RPM was (once off idle) then you should be getting a low voltage error on your MAF. And yes, that will cause your mileage to go down (way down). What is happening is breathing in enough air that your MAF should be providing 3V on it. If it only provides 1.48 V, then your PCM believes that your engine is only getting half the air that it is really getting and will only be supplying half the fuel that it is supposed to be supplying. What this will cause is your engine to run lean which will result in pinging. Since you already tried cleaning your MAF (and assuming you did it correctly) your next step would be to replace it. Buying a larger MAF is a better deal economically than buying a factory replacement from Ford.

 

[tisdale35]

Re: Re: testing MAF

Was there a sulfer smell coming out of your exhaust when you had problems?

Originally posted by Robert


Your increased RPM voltage should cover the range, depending on your RPM. If all you got out of yours was 1.48 V regardless of how high your RPM was (once off idle) then you should be getting a low voltage error on your MAF. And yes, that will cause your mileage to go down (way down). What is happening is breathing in enough air that your MAF should be providing 3V on it. If it only provides 1.48 V, then your PCM believes that your engine is only getting half the air that it is really getting and will only be supplying half the fuel that it is supposed to be supplying. What this will cause is your engine to run lean which will result in pinging. Since you already tried cleaning your MAF (and assuming you did it correctly) your next step would be to replace it. Buying a larger MAF is a better deal economically than buying a factory replacement from Ford.

 

[tisdale35]

clean them where?

Originally posted by jimmiecakes
I would try cleaning the MAF, first. What type and heat range of plugs did you use and what did YOU gap them to?

 

[Iggy flywheel]

On top of the MAF where the wires connect to it are safety torq screws. Take them off and pull of the plastic cover. There are 2 wire filements. Most use a carb type of cleaner spray. ProM recommends windex or a pipe cleaner to clean the filements. They say it might be to harsh. I would becareful with the pipe cleaner dont want to break the filements. If you use carb cleaner let it dry or use low air presure to help dry. Put back together and you done.

 

[tisdale35]

I went to Autozone yesterday after asking "where to clean" and asked them to test it for me (after I cleaned it of cource, I had already cleaned the elements) the guy said yes Autozone has a new policy they will hook it up and diagnose the system with a code reader that only costs $30.00@Autozone for FREE. If I'd have went there 3 days prior I would have saved $200.00. My MAF tested bad which it did when I tested it. I got 0.00 v at idle. I had already changed the O2 sensors and the TP sensor and bought a Chilton manual (which is a good investment always). I hated Autozone till yesterday so I will go back whenever it happens again or just buy the code reader. Thanks man.

Originally posted by Iggy flywheel
On top of the MAF where the wires connect to it are safety torq screws. Take them off and pull of the plastic cover. There are 2 wire filements. Most use a carb type of cleaner spray. ProM recommends windex or a pipe cleaner to clean the filements. They say it might be to harsh. I would becareful with the pipe cleaner dont want to break the filements. If you use carb cleaner let it dry or use low air presure to help dry. Put back together and you done.