Questions about adjusting the screw underneath the maf sensor

[talontsiboy24]

Im wondering if that screw underneath the maf sensor should ever be touched the one with the silicone over it? i heard u can lean out your car if u adjust it a lil is this true? My buddy broke the silicone off and turned the screw a lil is that bad? Should i put it back the way it was? i dont remember how it was positioned before though

Ever since he adjusted that screw a lil at wot my air fuel ratios went to 10.8-11.1 before it was rich as hell like 10.0....But he also noticed my intake pipe was too close to the maf sensor so he pulled it back some and then tightened it up and we went for some runs and no more 10.0 they got better alot better...so should i just put silicone where the screw was and leave it or adjust it back again and then put silicone over it?

Do you guys think it was because the intake pipe was too close to the maf sensor causing me to run real rich? Did pulling the intake pipe away from the maf sensor make my afr's better or was it the maf sensor screw?

last time i did a bl test and i had a leak from a intercooler coupler and air fuel ratio was 10.0 at wot but today we replaced the coupler with a new one and it still was leaking cause the pipe is bent and no matter how tight i go it still leaks but my air fuel ratios were 10.8-11.1 can it be the new coupler helped out even though its still leaking? Im confused which one these helped me out?

 

[williillii]

Its a calibration screw they use at the factory. Thats why there is silicone over it.

 

[talontsiboy24]

So the original position of that screw is turning it all the way in right? What kind of silicone should i put over the screw? i heard if u remove the silicone it can leak so i wanna seal it back up.

 

[williillii]

No, the original position was whatever it took to get the MAF to read within spec during testing and calibration. I dont think anyone will be able to tell you that. Id get it as close as you can to the original position and then silicone it up...Id imagine any kind will work.

 

[talontsiboy24]

No, the original position was whatever it took to get the MAF to read within spec during testing and calibration. I dont think anyone will be able to tell you that. Id get it as close as you can to the original position and then silicone it up...Id imagine any kind will work.

I found this link about the maf calibration screw what do you think? DSM 2g MAS Modifications - My Pro Street

 

[BoostedTalonTS]

by backing the adjustment screw out (flush with the rest of the lower passage on the MAF), it will cause more unmetered air to pass through the lower section. As long as you have a way to log & adjust for this, there is no reason why you should not run it this way... If you are using DSMLink, you can adjust for this easily.

Any leak in the IC piping (after the MAF) will cause a rich condition... The computer is using the data taken from the MAF to calculate fuel for the air that has already been metered at the MAF... If any is leaking out after the MAF, the computer will have already added fuel for the amount of air that has been metered. For this reason, it is usually a bad thing to externally vent your BOV rather than route the BOV dump back into the intake pipe, after the MAF.

 

[talontsiboy24]

by backing the adjustment screw out (flush with the rest of the lower passage on the MAF), it will cause more unmetered air to pass through the lower section. As long as you have a way to log & adjust for this, there is no reason why you should not run it this way... If you are using DSMLink, you can adjust for this easily.

Any leak in the IC piping (after the MAF) will cause a rich condition... The computer is using the data taken from the MAF to calculate fuel for the air that has already been metered at the MAF... If any is leaking out after the MAF, the computer will have already added fuel for the amount of air that has been metered. For this reason, it is usually a bad thing to externally vent your BOV rather than route the BOV dump back into the intake pipe, after the MAF.

All i have is a custom made chip for my mods no link or afc but i do have a vac/boost gauge n wideband and my bov is recirculated.

 

[BoostedTalonTS]

If you don't already have one, I'd invest in a data logger & at least an SAFC... In my custom EPROM chip days, I've found that the chips got things close but it was always nice to fine tune the setup... PM me if you are interested in getting either of these items, as I'm parting out a local DSMer's FWD 92 Talon & he has both of these for sale

 

[talontsiboy24]

If you don't already have one, I'd invest in a data logger & at least an SAFC... In my custom EPROM chip days, I've found that the chips got things close but it was always nice to fine tune the setup... PM me if you are interested in getting either of these items, as I'm parting out a local DSMer's FWD 92 Talon & he has both of these for sale

By the way the calibration screw isnt backed out all the way to flush...I screwed it all the way in and backed it out 4 turns. By looking at a bunch of stock 2g mafs's its about right where i have it now so i think i should be fine i really think it was the maf being too close to the intake pipe causing me to be super rich since the adjuster screw on the bottom of the maf has a small effect, and it's mostly at low airflow levels which i didnt notice anything difference. By the way my car is a 1g with a 2g mas if that makes a difference.

This dsmer on here told me this=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.

 

[BoostedTalonTS]

By the way the calibration screw isnt backed out all the way to flush...I screwed it all the way in and backed it out 4 turns. By looking at a bunch of stock 2g mafs's its about right where i have it now so i think i should be fine i really think it was the maf being too close to the intake pipe causing me to be super rich since the adjuster screw on the bottom of the maf has a small effect, and it's mostly at low airflow levels which i didnt notice anything difference. By the way my car is a 1g with a 2g mas if that makes a difference.

This dsmer on here told me this=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.

I was saying to run it with the screw backed out all the way... Especially if you are running a 10:1 AFR! This will in effect lean out your setup slightly.

Unless you shoe-horned that 2g MAF into the stock 1G rubber intake, I have no idea of what the other DSMer is talking about. You might want to update your mod profile and/or post some pics. Backing this screw out is one of the oldest tricks in the book towards leaning out a rich condition without any sort of real-time tuning (SAFC or DSMLink)... www.VFAQ.com has a few interesting reads on the subject:

MAFMod

Even though you are using a 2G MAF, the principle is the same... I've done the same mod on my 2G MAF with no ill effects.

As far as other possible boost leaks go, I'd strongly recommend looking into your 1G throttle body's shaft seals... These are notorious for leaking even under stock boost levels. Here's a good write up here:

Throttle Body O-Ring

 

[talontsiboy24]

I was saying to run it with the screw backed out all the way... Especially if you are running a 10:1 AFR! This will in effect lean out your setup slightly.

Unless you shoe-horned that 2g MAF into the stock 1G rubber intake, I have no idea of what the other DSMer is talking about. You might want to update your mod profile and/or post some pics. Backing this screw out is one of the oldest tricks in the book towards leaning out a rich condition without any sort of real-time tuning (SAFC or DSMLink)... VFAQ Site - Visual Frequently Answered Questions has a few interesting reads on the subject:

MAFMod

Even though you are using a 2G MAF, the principle is the same... I've done the same mod on my 2G MAF with no ill effects.

As far as other possible boost leaks go, I'd strongly recommend looking into your 1G throttle body's shaft seals... These are notorious for leaking even under stock boost levels. Here's a good write up here:

Throttle Body O-Ring

See how my maf was pushed to close to the intake pipe? well i pushed the maf with the air filter as far back as i can go where the coupler would be by the edge of the intake pipe and tightened it up after i did that my afrs went leaner.