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General MAF sensor screw and intake pipe adjustments helped my afr's?

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talontsiboy24

10+ Year Contributor
869
3
Mar 28, 2009
60457, Illinois
So my car was running 10.0 at wot with a boost leak from a intercooler coupler and my buddy took some of the silicone off the maf sensor screw and turned it just a lil bit and also said that my 2g maf coupler going to the intake pipe was pushed to close to it so he pulled it back till the coupler was nice and round with the the pipe like almost at the end and tightened it up we went for some runs and my air fuel ratios went from 10.0 to 10.8-11.1 wow what a difference can these things have helped me out?

I did have a boost leak from 1 intercooler coupler when this was going on and i have a lil exhaust leak goin on before the turbo i wonder what will happen when i get those 2 fixed.

I found these links about the maf sensor calibration screw seems totally fine to adjust it= http://www.roadraceengineering.com/eclipsetech/2gmasadjustment.htm http://my.prostreetonline.com/t100.htm
 

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It was probably going a little rich from the boost leak to be honest with you, he just band aided the problem for you by playing with the screw. That screw on the bottom of your MAF is a AFR calibration screw, turn it CW to richen things up and turn it CCW to lean things out. Of course theres only so much it can do but for fine tuning your AFR's its not a bad way to go.
That sounds like someone being OCD because really that has nothing to do with AFR's, no worries though since that coupler is always in vacuum and can't blow off.

:dsm:
 
It was probably going a little rich from the boost leak to be honest with you, he just band aided the problem for you by playing with the screw. That screw on the bottom of your MAF is a AFR calibration screw, turn it CW to richen things up and turn it CCW to lean things out. Of course theres only so much it can do but for fine tuning your AFR's its not a bad way to go.
That sounds like someone being OCD because really that has nothing to do with AFR's, no worries though since that coupler is always in vacuum and can't blow off.

:dsm:

Well should i put some silicone over the screw for now i heard they could leak? and for the maf coupler to the intake pipe should the maf be pushed close as u get it with the pipe for better flow or it doesnt matter? My intercooler coupler is brand new so that isnt the problem its the intercooler core the pipe that sticks out of it has a dent in it so no matter how i tightened up the pipe and coupler to it still leaks which sucks but i hate the long route piping anyway just gonna buy a short route kit and then i wont be leaking anymore.
 
I'd keep the pipe at the edge of the coupler. Don't push it all the way in. If the pipe is all the way inside the coupler, the edges will block off the sides of the maf, and that will send more air through the center metering chamber which will artificially raise the Hz count and make it run a little richer.

The adjuster screw on the bottom of the maf has a small effect, and it's mostly at low airflow levels.
 
I'd keep the pipe at the edge of the coupler. Don't push it all the way in. If the pipe is all the way inside the coupler, the edges will block off the sides of the maf, and that will send more air through the center metering chamber which will artificially raise the Hz count and make it run a little richer.

The adjuster screw on the bottom of the maf has a small effect, and it's mostly at low airflow levels.

Thats what this dsmer told me why im running richer cause the maf was too close to the pipe we backed it off and my afr's leaned out at wot which i needed. but im also thinkin it was cause he turned that screw just a lil bit but im sayin should i put silicone over it?
 
They put silicone over it cause it wont leak right?

Right. To apply it correctly, take the screw out, gently clean off the old silicone, apply new silicone (RTV, Tub-N-Tile caulk, etc.) push some into the threads on the screw, don't put any in the hole, and put the screw back in. Screw it in until it's flush with the bottom of the passage if you want it to read slightly lean, or screw it in 4 turns more if you want it to read like stock.
 
Right. To apply it correctly, take the screw out, gently clean off the old silicone, apply new silicone (RTV, Tub-N-Tile caulk, etc.) push some into the threads on the screw, don't put any in the hole, and put the screw back in. Screw it in until it's flush with the bottom of the passage if you want it to read slightly lean, or screw it in 4 turns more if you want it to read like stock.

Well should i just leave the screw how it is? Before i was running rich as hell 10.0 at wot but i have a boost leak from a intercooler coupler and i cant fix it but with that boost leak,adjusting the maf screw also pushing the maf away from the intake pipe put me at 10.8-11.1...But im wondering once my boost leak is fixed am i gonna go more lean or rich? The silicone isnt completley removed from the screw so should i just throw a lil more over it?
 
Relax, the screw doesn't make that much difference.
A boost leak will make it run richer at WOT. Fixing the leak will lean it out a little, depending on how big the leak is.
 
Relax, the screw doesn't make that much difference.
A boost leak will make it run richer at WOT. Fixing the leak will lean it out a little, depending on how big the leak is.

Well one of those adjustments i made had to make me run leaner cause right before i did those things my afrs were 10.0 at wot with the boost leak. Just wish i knew which one made me leaner. Well i found this on rre is website i guess its ok to adjust that screw here is the link= http://www.roadraceengineering.com/eclipsetech/2gmasadjustment.htm
 
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Right. To apply it correctly, take the screw out, gently clean off the old silicone, apply new silicone (RTV, Tub-N-Tile caulk, etc.) push some into the threads on the screw, don't put any in the hole, and put the screw back in. Screw it in until it's flush with the bottom of the passage if you want it to read slightly lean, or screw it in 4 turns more if you want it to read like stock.

Well from the factory the screw is covered up so is the whole with silicone so i just cleaned out the hole and filled it up with silicone so that should be fine right?
 
My guess as to why the hole is filled is not for leak reasons as much as it's a tamper deterent. Really shouldn't mess with that screw at all. Once you find and fix your boost leaks you'll have off AFRs again.
 
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