Backing out the MAS screw [Archive]

TJC

09-20-2002, 07:27 PM

I'm curious too. Unless you took the MAS apart, hehe. Or did you mean the idle screw on the TB.

If it is the idle screw on the TB, it only allows more air to go in so you will idle higher. It will not lean you out as the ECU will compensate for more air that you've let in and also increase the fuel too.

Auto-9

09-20-2002, 07:40 PM

I backed out the little screw on the black box with the sensors in it between the air filter and the intake plenum...my dealer is going to kill me. I read about it on Club 3G when members started running rich after installing a CAI and downpipes, and I noticed my exhaust smelled pretty bad too, so I went out and did this mod. Here's my results...Righties...for all of you folks still not convinced that the grinding/whirling type sound is coming from your CAI, I have confirmed it. How? I left the bottom half the the CAI off while starting the car (i.e. MAS to the intake plenum only pipe) and sure enough it was loud as heck and coming from inside the MAS. Also...since I didn't know how far to back out the screw I only did enough to see 2 threads of the screw and that was it...I had it out to 3 threads and my car died on me, so I pushed it back into to 2. On the test drive I didn't really feel anything different, positive nor negative (as long as it's not negative it's good enough for me), and it still smells pretty darn bad...but I'm not gonna adjust it any more since it has a tendency to die on me...

BlueESV6

09-20-2002, 08:33 PM

<div class='quotetop'>QUOTE(TJC)</div><div class='quotemain'>I'm curious too. Unless you took the MAS apart, hehe. Or did you mean the idle screw on the TB.

If it is the idle screw on the TB, it only allows more air to go in so you will idle higher. It will not lean you out as the ECU will compensate for more air that you've let in and also increase the fuel too.</div>

Not that I'm any expert on the idle adjust but I thought manybrews was mentioning on a car problems post that the idle was not adjustable but all automatic? Would this mess up the car's settings? Thanks https://www.thegalantcenter.org/style_emoticons/default/smile.gif

TJC

09-20-2002, 09:51 PM

<div class='quotetop'>QUOTE(BlueESV6)</div><div class='quotemain'>
Not that I'm any expert on the idle adjust but I thought manybrews was mentioning on a car problems post that the idle was not adjustable but all automatic? Would this mess up the car's settings? Â*Thanks https://www.thegalantcenter.org/style_emoticons/default/smile.gif</div>

I think it was timing is automatic and not the idle. That would be crazy if there wasn't a way to adjust your idle. Plus if you look at the TB, all it does is open/close up a path way for the air to bypass the butterfly valve in the TB. If it wasn't adjustable, why the idle screw then.

Rallifan, that's interesting about the MAS. I'll look into the manual to see if there is any info on that.

TJC

09-20-2002, 09:57 PM

No info in the service manual about the Air Flow Sensor Assembly. https://www.thegalantcenter.org/style_emoticons/default/sad.gif
Guess Mitsubishi thought there was nothing that needs to be adjusted in there. Nothing was even mentioned in troubleshooting the Intake System.

smoothrollin

09-20-2002, 11:13 PM

If you adjust the TB like is mentioned in the tutorials, will that not increase performance, and will it burn up more gas.

TJC

09-20-2002, 11:19 PM

<div class='quotetop'>QUOTE(smoothrollin)</div><div class='quotemain'>If you adjust the TB like is mentioned in the tutorials, will that not increase performance, and will it burn up Â*more gas.</div>

What tutorial is that? Tightening the accelerator cable or adjusting the idle screw? Either way, neither really increases performance, lol.

smoothrollin

09-20-2002, 11:22 PM

I don't know. He just said to follow the throttle cable to the end where there is a flat cable and loose the two screws on the plate and move the plate back.
What will that do.

TJC

09-20-2002, 11:39 PM

<div class='quotetop'>QUOTE(smoothrollin)</div><div class='quotemain'>I don't know. Â*He just said to follow the throttle cable to the end where there is a flat cable and loose the two screws on the plate and move the plate back.
Â*What will that do.</div>

Oh okay. That mod is just to take the slack out of the accellerator cable. Quicker response time on the throttle is what that does. The two screws mentioned in that mod goes to the top of the intake manifold where that plate with the two screws are which is no where near the throttle body (TB).

The idle screw is right on the TB. It raises or lowers your rpm at idle regulated by how much air it lets pass.

smoothrollin

09-20-2002, 11:42 PM

So is there any mods like that, that I can do to help with performance. Things that don't cost too much. at least right now.

TJC

09-20-2002, 11:51 PM

<div class='quotetop'>QUOTE(smoothrollin)</div><div class='quotemain'>So is there any mods like that, Â*that I can do to help with performance. Â*Things that don't cost too much. at least right now.</div>

Sorry Rallifan for getting off topic and polluting your thread, hehe. I'll pm smoothrollin.

Auto-9

09-21-2002, 12:55 AM

Heehee...np...now for extended testing results (80 miles total distance tested)...my car idles at 500 rpm and will shudder a little before upping the rpm to about 600 and falling back down to 500 if I turn the A/C off...very risky https://www.thegalantcenter.org/style_emoticons/default/smile.gif On the bright side my throttle response has improved insanely, my car revs faster, holds revs longer, shifts smoother, and feels tons stronger...my guess is I really was running too rich. Plus I dunno what I did but my car sounds a whole bunch meaner when at WOT and very smooth tone the rest of the time. I'm glad I did this...my fuel consumption has dropped too https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif Too bad it still smells really thick...

toc8g

09-21-2002, 04:33 AM

Yeah I did this along time ago on my old silver car,..I also got the idea from the 3g club and on Club DSM site,..It seemed to work out ok,..I mean my car never died out like yours but it seemed to do what you described. As matter of fact I still have the MAS from my old Galant and instead of tearing that rubber seal off my new mas I will just swap out the mas! :wink:

Fishboy55

09-21-2002, 06:00 AM

Rallifan, can you or TOC post the thread from club 3g about this mod please? I'm not sure I'll mess with it, heck I don't even know if my car is running rich or not, but it's at least worth looking into. Thanks guys.

Chip

Auto-9

09-21-2002, 09:42 AM

Righties here's some of the best threads I think: http://www.eclipseforums.org/showthread.ph...light=MAS+screw ('http://www.eclipseforums.org/showthread.php?s=&threadid=52174&highlight=MAS+screw') and http://www.eclipseforums.org/showthread.php ('http://www.eclipseforums.org/showthread.php')? and http://www.eclipseforums.org/showthread.ph...light=MAS+screw ('http://www.eclipseforums.org/showthread.php?s=&threadid=9645&highlight=MAS+screws=&threadid=9992&highlight=MAS+screw') The last link is a post that has pics that link to Road Race Engineering...it's what I used as a visual aid for myself. It's really fun...I get torque steer now at 75 mph if I floor it https://www.thegalantcenter.org/style_emoticons/default/smile.gif

Fishboy55

09-21-2002, 10:06 AM

Thanks Rallifan. Looks like I'm headed out to the driveway later to back that screw out until it's flush. I'll let you know what happens.

Chip

Auto-9

09-21-2002, 10:08 AM

Just remember to reattach your air filter, even if you're not securing it, before starting up the car, or else it'll die on you like it did me from too much air https://www.thegalantcenter.org/style_emoticons/default/laugh.gif It's good to have a little restriction once in a while https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif

BlueESV6

09-21-2002, 01:59 PM

I knew I wasn't dreaming when I read the idle was not adjustable. Manybrews was responding to the "I'm Running Rich" post under car problems.

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'>the idle is totally automatic. if its not idling at 750 +-, its ROYALLY screwed up.

a little tip.. there is NOTHING that needs adjustment on the throttle, ever.. Â*
if you messed with it, youve probably screwed it up.
if its idling wrong without being adjusted, something has failed.

and just increasing the idle will NOT make it run rich, as the fuel system will easily compensate for that. so something else is screwed up.</div>

This was he wrote about it... I personally have no clue just passing this along to you...

Good Luck with it, hope you get it idleing better. Mine was idling bad a month ago and manybrews suggested cleaning the throttle body out. A few squirts of carb cleaner did the trick :wink:

Fishboy55

09-21-2002, 05:53 PM

I ran the screw out of my MAF until one thread was showing. Didn't notice any change in idling or sound when I started the car up. But when I got to the top of my street and turned out, I left a little squeel behind. Something that never ordinarily happens. I thought it was just a coincidence, but after driving around, I have definately got more low end response than I had before. The car is truly quicker. Of course without an AFC I can't tell you if I'm running any more or less rich than I was before. But I can feel a noticeable difference. We'll leave it turned out and see if there's any long term effects. Thanks Rallifan.

Chip

RedGalant2k1

09-21-2002, 09:56 PM

<div class='quotetop'>QUOTE(Fishboy55)</div><div class='quotemain'>I ran the screw out of my MAF until one thread was showing. Didn't notice any change in idling or sound when I started the car up. But when I got to the top of my street and turned out, I left a little squeel behind. Something that never ordinarily happens. I thought it was just a coincidence, but after driving around, I have definately got more low end response than I had before. The car is truly quicker. Of course without an AFC I can't tell you if I'm running any more or less rich than I was before. But I can feel a noticeable difference. We'll leave it turned out and see if there's any long term effects. Thanks Rallifan.

Chip</div>

SOunds like something i should do :thumbsup:

Auto-9

09-21-2002, 10:21 PM

Hehe...so maybe it's not all in my head https://www.thegalantcenter.org/style_emoticons/default/smile.gif

smoothrollin

09-21-2002, 11:22 PM

Which screw do you back out

Auto-9

09-22-2002, 02:28 AM

Ok there's a black box with sensors somewhere in the middle of your air intake path, with a bundle of wires coming out from the left side (towards the engine). If you can flip it so that the under side is facing up, you'll see a little circle that has soft stuff in the middle. You have to destroy that material to get to see the screw. It's a screw big enough (about a quarter to half an inch maybe) to be turned by a flathead screw driver. The 3rd link I posted has a link to Road Race's pics, very helpful.

g96nt

09-22-2002, 07:43 AM

ralli.. if your car is Running rich, or stinks like Ass.. why not Try Replacing o2 sensors? ~$50 from conicelli

do you have a S-afc to keep an eye on the front one?

if that doesn't work... try replacing the catcon.
(good excuse to buy a 2.5" hi-flow)

MnGalant

09-22-2002, 03:55 PM

I backed mine out so i could see two thread. The car just drives so much better and smell normal when i accelerate hard. My girl even drove it with out knowing what i did and said the car was driving much nicer, shifted really good and was better off the line.

Auto-9

09-22-2002, 03:57 PM

Well I guess it's official...somehow the screw is adjusting stuff https://www.thegalantcenter.org/style_emoticons/default/smile.gif All I know is I like what it did whatever it was https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif

BlueESV6

09-22-2002, 09:16 PM

Sounds like I'll be trying this mod when I get a CAI...
Besides giving more apparent power... what is that screw for???

Anyone know?

Auto-9

09-22-2002, 10:23 PM

The only reason it may be giving more power is because for some reason it seems to be affecting whether we run richer or leaner. With my CAI and downpipe I was running rich for some reason, so I backed it out to help run leaner...it's basically a poor man's S-AFC.

RedGalant2k1

09-22-2002, 10:28 PM

Where is the screw again? isn't it on the bottom of the MAS?

Gspeedvr42k1

09-22-2002, 10:48 PM

still cant find it....

Gspeedvr42k1

09-22-2002, 10:53 PM

wait is this on the stock airbox? or cai only..

RedGalant2k1

09-22-2002, 10:54 PM

<div class='quotetop'>QUOTE(Gspeedvr42k1)</div><div class='quotemain'>wait is this on the stock airbox? or cai only..</div>
neither. its on the bottom of the MAF sensor inbetween both pieces of pipe.

Gspeedvr42k1

09-22-2002, 11:00 PM

yo, wait MAF pipe? is it gonna be on the stock intake anywheres

Fishboy55

09-23-2002, 07:56 AM

<div class='quotetop'>QUOTE(Gspeedvr42k1)</div><div class='quotemain'>yo, wait MAF pipe? is it gonna be on the stock intake anywheres</div>

The MAF is the thing on the end of your airbox with the 6 pin electrical plug on it. It's kinda square. If you take it off and flip it over you'll see the silicone sealant about the size of a nickel on the underside. Once you cut that sealant off, the screw will be under it. It's a big screw, the size of the hole you just uncovered. Use a flat blade screwdriver and turn it out. How far is up to you and up to how your car responds. So far we've had people make it flush to the casing, one thread out and two threads out. After you adjust the screw, put everything back together. Remember to plug the MAF connector back in. Then start your car.

Chip

Prophet

09-23-2002, 10:37 AM

Can you do the same mod with only a CAI and exhaust or only if you have the headers and such is this useful and what could the side effects be if anyone knows.

Jason

Fishboy55

09-23-2002, 10:51 AM

<div class='quotetop'>QUOTE(Outlawzcc)</div><div class='quotemain'>Can you do the same mod with only a CAI and exhaust or only if you have the headers and such is this useful and what could the side effects be if anyone knows.

Jason</div>
Hey Jason,

Mods don't seem to matter. The only reason Rallifan and I did it is because both our cars were running slightly rich. But according to the articles from club 3G, it seems to have no side effects unless you lean your car out too much, but you'd likely notice that right away. I'd suggest you try it and see what effects it has, especially in your low end. That's where I noticed the most. If it doesn't work you can always turn it back in.

Chip

Mante

09-23-2002, 11:26 AM

Hey guys, I came across this thread late lastnight...initial thoughts were yea, ok..sure uh huh... I kept getting pm's, IM's emails and such and decided to try it. So after spending the 5 min to do this I realized 2 things...1 I still need a fpr (chip could help with that lol) because my fuel cut off is around 4100 rpm. 2 alittle gains have been achieved as far as fuel economy.

Im not sure if this is due to my ram air, heavy foot or mental. Either way you no harm can nor will be done by doing this. I'd recommend using lock tite or something to keep the screw inplace

Gilhuly

09-23-2002, 12:07 PM

If it were really going to make the engine run too lean the ECU would kick off a check engine light, no? The last of the Club 3G posts provided above (thanks) was pretty helpful for understanding this.

Gspeedvr42k1

09-23-2002, 05:47 PM

I'd recommend using lock tite or something to keep the screw inplace.

Duct Tape! worked for me can work for you

i tried this mod and umm.. i kinda didnt notice anything... and i have it about 2 threads out.... help....?

PS. thanks fishboy

MnGalant

09-23-2002, 06:38 PM

How will i now if i am running lean with out using a af gauge. Second on the 3g club they brought up using this in winter but they didnt get into depth with it . I live in minneapolis and it get pretty cold so should i twist it back in around winter time.

Fishboy55

09-23-2002, 06:42 PM

Usually you can tell because your car stutters a little when it's lean. You can sometimes feel it in the idle. Also, and this is worst case, you'll hear it knock. That's very bad.

I don't really see how it's going to make any difference in the winter. I don't see why you'd want to run rich anytime of year. I'm sure someone here must have some ideas on this. I'm surprised we haven't heard from our resident tech manybrews on what we're all doing by turning this screw. LOL.

Chip

00GTZ00

09-24-2002, 07:10 AM

uhmmmmmm maybe I should give this a try today... my car started shuttering a little at idle, Maybe I am running too lean, or rich... https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif

Auto-9

09-24-2002, 08:36 AM

You sure it's not the wife? https://www.thegalantcenter.org/style_emoticons/default/smile.gif

BlueESV6

09-24-2002, 07:47 PM

TJC

09-26-2002, 01:54 AM

I used o pull a plug to check for lean... has anyone pulled a plug to look at it? (compared with a plug before this mod was done)

I sure am curious what the heck that screw does... it obviously was not meant to move once set from the factory (sealant covered)....

Absolutely. The old way was to inspect the plugs for symtoms of how your engine is running. I believe you can get pictures of plug analysis on Union76 gas' website.

BlueESV6

09-27-2002, 01:10 PM

Found this on the RRE website regarding the MAS screw and what it does...

www.roadraceengineering.com/eclipsetech/2gmasadjustment.htm

Big H Killa

10-03-2002, 09:27 AM

what's this honeycomb thing

Fishboy55

10-03-2002, 09:31 AM

It's the air diffuser inside your MAF. Read the article from RRE and it'll tell you all about it.

cdaw2001ES

10-18-2002, 09:30 PM

My honeycomb is all one piece. it is not in sections like on RRE's site. I left it all together.

I am seeing a decreased performance, when cold starting, in cold temperature. Engine runs excessivley to the lean side, while still in the pre heat static fuel map, As soon as the 02 heats up and the car switches to bouncy mode things get back to normal

Otherwise I'm loving my car at the moment

T.S.

10-20-2002, 12:40 AM

I just went out to my car, dug out that screw and backed it out a little past flush, then went speeding around the neighborhood at 12:30am for a little bit and the car definatly pulls a little harder, crazy https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif

99DE

10-20-2002, 07:59 PM

I'm going to try this tomarrow at work. I think this mod should be added to thegalantcenter.com mod page with a tutorial. I always love FREE performance mods.

99DE

10-21-2002, 06:14 PM

Did it today at work, it was ez. On the ride home, I can feel the throttle response is much better. Now I'm curious about doing the Air breather mod and see if I can pick up even more action.

Danger DANJ

10-22-2002, 01:03 PM

Those of you who have done the mod already, can you also turn the screw so it goes in further instead of backing it out? I ask because since I have problems with my car idleing funny in the cold, I'd think that I would want to richen things up instead.

Auto-9

10-22-2002, 02:02 PM

Good question...didn't think about screwing it in before screwing it out...

Tiptronic

10-22-2002, 05:55 PM

is this the black box you are talking about

http://www.ptuning.com/graphics/injen/rd1866wm.jpg

pinoyesv6

10-22-2002, 06:30 PM

yea thats teh black box...

TJC

10-22-2002, 06:32 PM

is this the black box you are talking about

http://www.ptuning.com/graphics/injen/rd1866wm.jpg

Yes! That part is not from Injen as shown in their Race Division CAI. That is the MAS or MAF adapter that is bolted on your stock air box with 4 nuts and also has the wire harness hooked up to it. Under that MAS is a round opening about the size of a nickel that's covered with rubber silicone. The big long slit used to turn that plastic in or out is underneath the silicone. Just make sure you make a mental note of how far the setting was originally by looking in the honeycomb part and seeing how much of the hole it was set at stock. Mine was actually more than half of the hole. You can keep backing it out until you have problems idling and then turn it back in a little.

As others have said, if you have problems idling while warming up the car in the mornings, you might also want to turn it in instead. Good luck.

Tiptronic

10-22-2002, 08:58 PM