Anyone know how to adjust air/fuel ration using the MAF meter? ?

[FastGT50Stang]

Anyone know how to adjust air/fuel ratio using the MAF meter? ?

My air fuel ratio gauge is reading pretty lean; it's mostly in the red zone and almost never in the green...

Over in 5.0Talk Grey5.0Beast told me he read an article on the internet saying something about how you can adjust the AF ratio by adjusting the MAF meter/sensor, i don't know clockwise or counterclockwise, and doing that it mix more air or more fuel...anyone with this info. or article, please post some replies...

thanks
Stan

 

[Black1987Stang]

Thats called clocking the maf, i wouldnt say thats an accurate way of "tuning" but idk. It was in one of the recent stang magazines where they put the turbo on the kids stock stang and it said which way was to rich, lean etc. I wouldnt do tuning by the air/fuel gauge unless you have a wideband one. The stock 02 sensors arent that accurate, I have one of the autometer air/fuel gauges too and i just basically have it hooked up for the pretty lights and for show or a general idea of my air/fuel mixture. Mine will show real lean when my maf likes to conk out which is whenever it wants, it will be off the scale lean at idle and once i get up some rpms it finally shows some lights. Then once I hit the top of the maf with my dykes it will work normal again lol and it will go back and forth between lean and stoichmetric and wont go past that unless i realy get on it.

 

[speedytang]

C&L meters you need to rotate sometimes to get a better reading. A electronic calibrated meter usually does not. I am sure you can just move the meter but without a real A/F meter and not the idiot light Autometer style your never going to get it perfect and probably will need to rotate it all the time to keep a good reading.

 

[jrichker]

Clocking the MAF does not change the basic Air/Fuel ratio. It does put the inlet for the sensing element in a place where the airflow through it is smooth and constant. Turbulence in the MAF's inlet can cause the MAF output to be erratic, upsetting the computer's ability to deliver the correct amount of fuel for the amount of air entering the engine. If the MAF sensor output is unstable, the engine will surge and have drivability problems.

 

[HISSIN50]

One can use something like a MAF tuner or Optimizer (I think - I have not used or researched those) to help get the MAF in synch. Kind of pricey options though.

It seems to me that if big mods are planned, a TwEECer is a nice way to go since you can endlessly manipulate the MAF curve.

 

[FastGT50Stang]

thanks for the replies...so basically i can't adjust it or it's jus not a good idea, but here's the thing, i know that there's sumthing wrong with my stang; it's not a super huge deal, but it gets on my nerves and i want to fix it...

Like when i start her up, whether it's cold out or not, and she sat all night, it fires up but the rpm's don't increase past you know 1500 to 2000 so that the engine can heat up on itself...therefore prob. not mixing enough fuel or vis versa mixing to much and overflowing..i don't know, i have to steadily keep my foot on the gas pedal so that way she warms up, and overall the engine doesn't sound right to me, like it should..

I think that i should go get it dyno tuned and just spend the 300 bucks or whatever and have the guys over there solve the problems with my air/fuel ratio... i think that's the last option i have to take...??

 

[vristang]

As for the maf clocking, the only way I can see this working is if you still have an elbow just before the maf. Then there would be a high velocity and low velocity area of flow at the maf. Can't see how it would affect the a/f ratio though, maybe temporarily until the computer has time to adjust? If I understand it right the O2s have the greatest amount of control over the a/f.

I have never been in a efi car that would idle at 1500 when cold. That is part of the beauty of efi, you don't have to waste fuel and piss off your neighbor at 4am by rapping out the engine.

If the car isn't running right, you should start with pulling the codes. This will clue you into what the problem is most of the time.
When was the last time you changed the O2s? They do go bad over time.

That is all I can think of right now.
Good Luck
jason

 

[FastGT50Stang]

As for the maf clocking, the only way I can see this working is if you still have an elbow just before the maf. Then there would be a high velocity and low velocity area of flow at the maf. Can't see how it would affect the a/f ratio though, maybe temporarily until the computer has time to adjust? If I understand it right the O2s have the greatest amount of control over the a/f.

I have never been in a efi car that would idle at 1500 when cold. That is part of the beauty of efi, you don't have to waste fuel and piss off your neighbor at 4am by rapping out the engine.

If the car isn't running right, you should start with pulling the codes. This will clue you into what the problem is most of the time.
When was the last time you changed the O2s? They do go bad over time.

That is all I can think of right now.
Good Luck
jason

well, about 3-4 months ago i installed those bassani long tubes, and drove open headers for a good 3 weeks on the streets...wow that was so f-ing loud and i didn't change my O2 sensors, which i prob. should have, then i put my bassani x-pipe on and drove like that for 1 week until i installed my MAC flowpaths....the driving i did was on and off due to winter in chicago...

And just 3 days ago i changed my O2 sensors, although i haven't drove it yet with the new sensors in b/c she's on jack stands in the garage and it's also snowing over here...so wat u think, will it be better now or did i fu#k up in the beginning not changing the sensors and driving open headers; do you think that harmed anything?? like the AF ratio??

THANKS
Stan

 

[vristang]

If the problem was the O2s then your problem could very well be solved.
Just drive it for a few miles to let the computer relearn the new sensors. maybe disconnect the battery for 1/2 hour first. This can make the relearning process quicker.
I doubt driving with open headers and the old O2s could cause you any trouble. There are some who would say that open headers allow the O2s to cool too quickly, which can lead to rapid degredation or just plain old failure. I have no direct experience with that though.

It may still be worth the time to pull the codes though, since the car is in the garage anyway.

Hope the O2s work out for you.

jason

 

[FastGT50Stang]

If the problem was the O2s then your problem could very well be solved.
Just drive it for a few miles to let the computer relearn the new sensors. maybe disconnect the battery for 1/2 hour first. This can make the relearning process quicker.
I doubt driving with open headers and the old O2s could cause you any trouble. There are some who would say that open headers allow the O2s to cool too quickly, which can lead to rapid degredation or just plain old failure. I have no direct experience with that though.

It may still be worth the time to pull the codes though, since the car is in the garage anyway.

Hope the O2s work out for you.

jason

Thanks Jason for all your help, just one more question, what do you mean by pulling the codes? ?

 

[HISSIN50]

Thanks Jason for all your help, just one more question, what do you mean by pulling the codes? ?

Retrieve the trouble codes. Jrichker posts links about how to do so with a paperclip.

Good luck.

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

 

[vristang]

Thanks Jason for all your help, just one more question, what do you mean by pulling the codes? ?

Hope it works out for you.

By the way the last 2 guys to post know alot more than I do on the 5.0

In my opinion code readers are worth every penny.

:SNSign: