So I pulled my MAF off today and cleaned it good. I had heard somwhere that the positioning of the sensor had a lot to do with how the car ran. I was experiencing high idle, low idle, surging/bucking, hesitation.... the list goes on and on. Well I had the MAF directly below the inside corner on the powerpipe at like 6 o clock, which I guess is not good, So tonight I moved it to the outside bend of the powerpipe at 12 o clock and the car runs sooo much smoother. Only thing is its running pig rich right now!!! Im talking 11's/12's just cruising around. So is it save to say that I now have it in the right position and it needs to be retuned? Or did I somehow screw something up lol
cleaning and clocking MAF
- Thread starter 96snake719
- Start date
What did you clean it with? Electrical contact cleaner I assume? Lots of people use all kinds of shit to clean their maf and it causes all kinds of issues.
I used "mass air sensor cleaner" lol i used pretty much the whole can on the thing. The car is so much smoother now and the idle is where it needs to be its just running rich as hell.
using the screen?
screen?
just read your mods....with the blower, no screen. never mind. sorry 'bout that.
Haha thats cool, Just talked to the tuner he said no way around it gotta be completely retuned now great!...
The MAF wants laminar flow to accurately measure the mass of air flowing through it. Laminar flow means that there is no turbulence and the mass of the air flowing through the pipe is equally distributed across the cross section of the pipe.
The screen helps to cut down on turbulence, so you should not remove it.
When you put the MAF sensor close to a bend in the pipe, there tends to be more air molecules flowing near the outside of the bend compared to the inside of the bend. So if your MAF sensor is closer to the high flow part of the stream, it will indicate there is more air coming in than there really is. And if the MAF sensor is closer to the low flow part of the stream, it will indicate that there is less air coming in than there really is. Clocking the MAF is actually trying to get the MAF sensor into the part of the stream where the average flow is occuring.
It can be hard to do, because the differences in flow may move at different air velocities through the pipe.
When you start screwing around with non-laminar air flow across the MAF sensor, you really should have a tune, and even then you may not be happy under all conditions. Different clock positions will probably each need new tunes.
If you can, put the screen back in (restriction is not noticeable) and put the MAF sensor at the straightest part of the pipe you can find.
The screen helps to cut down on turbulence, so you should not remove it.
When you put the MAF sensor close to a bend in the pipe, there tends to be more air molecules flowing near the outside of the bend compared to the inside of the bend. So if your MAF sensor is closer to the high flow part of the stream, it will indicate there is more air coming in than there really is. And if the MAF sensor is closer to the low flow part of the stream, it will indicate that there is less air coming in than there really is. Clocking the MAF is actually trying to get the MAF sensor into the part of the stream where the average flow is occuring.
It can be hard to do, because the differences in flow may move at different air velocities through the pipe.
When you start screwing around with non-laminar air flow across the MAF sensor, you really should have a tune, and even then you may not be happy under all conditions. Different clock positions will probably each need new tunes.
If you can, put the screen back in (restriction is not noticeable) and put the MAF sensor at the straightest part of the pipe you can find.
so is the clocking as important on a stock setup? if so what position?
It shouldn't matter if the flow is laminar. I'd just leave it at 12 o'clock.
Im just hoping that when I get it tuned it wont just go back to doing what it did before. The bucking/surging hesitation crappy idle thing. Cause if I new that for sure Id save a couple hundred bucks, put it back to the way it was before and deal with it I guess lol
Have your tuner show you the datalog of the MAF AD counts. The line should be nice and smooth. Turbulence in the MAF will show up as a very noisy line on the graph. And it confuses the crap out of the PCM.
I swear this car has a mind of its own! yesterday when driving it around I was bottoming out my wideband at 10.0, and it was floating around 13.0 while cruising. Today I took it for another spin and now the wideband is reading between 11.0 and 11.8 at wot, and cruising around 14-15.0. could this be the turbulance your talking about making the computer not no how much fuel to throw at it?
This is one thread I don't think I've seen on here. First time I went to a dragstrip, in 2003 I think, a GT owner showed me that. I thought it was the coolest thing in the world, lol.
It's definitely a noticeable difference on my car when I fool with it, especially when it's cold.
It's definitely a noticeable difference on my car when I fool with it, especially when it's cold.
Thanx, will check to see where mine is.
hope that does it for you.
have you checked all your fittings and lines to make sure everything is tight and no air getting in anywhere it shouldn't?
It could be. It would be interesting to see a datalog of the MAF AD counts.
Yea that was one of my problems before, I had an air leak where my bypass was welded on and I had an air leak where that little set screw is in the top of the throttle body But I got that stuff all straightened around then I messed with the MAF, also one more thing to note is that when I got the car tuned the first time it was tuned on only 32 psi fuel pressure which I later found out is not even close to the stock setting of 39 psi and Im making almost 600 horse! So I def have to get that bumped up when I do it the second time.
Ill have to see if I can get a copy from him, should be able to.
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