metering plate/air cleaner

[philip j]

What does this plunger do? When I push down on it, the metering plate moves. When I push down on the metering plate, the plunger doesn't move. Do I need it, or can it be removed? Looking at pics, some cars seem not to have this devise. As you can see, it is hampering my efforts to install a aftermarket air cleaner. Maybe I should just cut the air filter? What have others done? thanks Philip

[Ronnie's.930]

See the last pic of post #9 - VERY important mechanism indeed!

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/547032-sticky-common-answers-why-my-car-doesnt-start.html

[Richard930]

You definitely need that!!!!

It's your mixture adjustment - you push down on it and turn it (it clicks) to adjust mixture. Counterclockwise to enrich, clockwise to lean.

[philip j]

Thanks for the direction to that thread Ronnie! OK, if it has to stay, how crucial is it that this has movement? Does it need complete clearances from obstruction? Does it actually even move when the motor is running, or just a port for adjustment. thanks Philip

[mooney265]

notch the filter...

[oilonly]

Here is another thread on that fuel mixture adjuster philip j.

adjusting mixture

[RarlyL8]

That's the same filter I use. Cut a "V" in the rubber top and bottom and cut the metal grid from top to bottom lining the cut up to the middle of the "V". Bend the metal grid back into the paper element forming that "V" and spreading the paper element so that the plunger sits untouched.

[Alan L]

Just from curiosity, how much gap do you have from the rubber thing straddling the air plate, and the bolt head - never could work that out.
I have a KN filter - it is notched in the rubber base. You want the pin free - otherwise you may jam it down when installing the filter. Very bad.
Alan

[krasuskyp]

Originally Posted by Richard930

You definitely need that!!!!

It's your mixture adjustment - you push down on it and turn it (it clicks) to adjust mixture. Counterclockwise to enrich, clockwise to lean.

Argh!

It's (L) (Left) (Lean) / (R) (Right) (Rich)!!!

My easy memonic for remembering. Not to mention, screwing it in (R) pushes the metering plate DOWN = more fuel.

I saw this post a few weeks ago and it totally threw me for a loop starting to 2nd guess what I'd always read / thought.

It's most def not counterclockwise to enrich! I just went thru this yesterday on mine sorting a lean issue.

Again: (L) (Left) (Lean) / (R) (Right) (Rich)!!!

Forums... a sometimes dangerous place 8-)...

[Miguel Antonett]

You better do it the way Paul is saying above; if not, bad things could happen at the track...

[pkracer21j]

Technically you DON'T need the spring loaded allen, all it does is push down into the actual allen screw that adjusts your mixture. you can remove it, and put a small bolt to plug the hole to prevent un-metered air. It will just be a little more involved to adjust your mixture.

[philip j]

was thinking also. Once I get to the adjustment phase for this round of mods, I will remove. thanks Philip

[krasuskyp]

...and contrary to my ignroance - you cannot just push the plunger down and twist it w/ your fingers - doesn't engage the screw in the bottom. I suck.

Philip - why in the world are you insistent on removing the screw!? Leave it in there - you'll need to adjust it even after mods, minor tweaks here / there. Sorry, I don't get it. I notched my similar filter and I can get to it w/ the filter on NO PROBLEM. Just sayin.

Thanks to The Porsche Whisperer and the 11pm dial-a-Petey phone calls, I sorted my lean issue. Pete, UDAMAN. Even called me the next morning to see how I made out heh heh.

Peteski... so now my car has a slight surge while, say, cruising light / constant throttle in 3rd gear. Like a pulsation of the power - very subtle, yet noticable. I added fuel until I got a black puff then backed off a C-hair, figured that was about right 8-). Any insight broham???

If you haven't met Pete - he truly is the f'n Horse... er... Porsche... Whisperer.

Madman, extraordinaire...

[mooney265]

Just to clarify - - it's not a 'mixture adjustment'

it's an 'idle mixture adjustment...' If I'm not mistaken, all it does is adjust the fuel mixture at idle [with the throttle body fully closed - - or, your foot off the gas...].

it doesn't adjust your cruise mixture... unless you're cruising with your foot off the gas pedal

[Richard930]

Yep - idle mixture adjustment, though it did seem to have a small effect on cruise mixture as well (on mine anyway).

Screwed up my own memory aid, probably because actually driving and adjusting my car is a distant memory thanks to winter. My memory aid (and I need lots of them) was turning it towards me (Rich) made it richer, away from me made it leaner. Now I remember that my reference point was standing behind the car making the adjustment (with the allen wrench on the right side of the adjuster) not sitting in the drivers seat - duh! So yes, I agree with Mr. Krasusky who has a much better way to remember.

Never take anything you read on the net as 100% correct - I'll go back to what I do best - drinking beer and looking forward to the driving season. Oh yeah, if you're playing with mixture, make sure you get an AFR meter so you know what's going on when you make an adjustment rather than finding out by melting a piston or two.

[krasuskyp]

Originally Posted by Richard930

My memory aid (and I need lots of them) was turning it towards me (Rich) made it richer, away from me made it leaner. Now I remember that my reference point was standing behind the car making the adjustment (with the allen wrench on the right side of the adjuster) not sitting in the drivers seat - duh! So yes, I agree with Mr. Krasusky who has a much better way to remember.

Never take anything you read on the net as 100% correct - I'll go back to what I do best - drinking beer and looking forward to the driving season

Amen Richard - fear not... I'm right there with you! Beer 'n driving (separately) are what I do best. Well that and being a dumbass - got that covered.

Uhhhh, your memory aid cracks me up tho - sitting in the driver seat (no matter where you sit - on the roof?)... the screw still turns (R) (Rich)! Too funny.

Hear ya on forgetting about the car - I finally cracked mine from winter's slumber Monday, commuting w/ it all week. Good to be back! Trying to sched the dyno as I type, dial that bish in after installing some bits - can't wait.

[RarlyL8]

You really can't screw it up too bad, if too rich the idle will oscillate, if too lean it will surge.
Also you should always end the adjustment with a tweak rich (right, right? Ha!) and a bump of the throttle to relieve tension on the stop created by the lean/left adjustment. The adjustment will change slightly once driven if this isn't done.

[krasuskyp]

Originally Posted by RarlyL8

You really can't screw it up too bad, if too rich the idle will oscillate, if too lean it will surge.
Also you should always end the adjustment with a tweak rich (right, right? Ha!) and a bump of the throttle to relieve tension on the stop created by the lean/left adjustment. The adjustment will change slightly once driven if this isn't done.

Errr...

I'm getting a slight idle oscillation - AND a slight 'surge' while cruising part-throttle (ONLY <3k).

So I'm running richly lean? Or leanly rich? Neither? Both? Argh! My head hurts.

Any insight? I've got a call into my dyno guy, was hoping to make a run @ lunch today but no call back yet.

[ertech]

does this have to be capped once adjusted not to let unmetered air in?
Thanks

[pkracer21j]

Originally Posted by mooney265

Just to clarify - - it's not a 'mixture adjustment'

it's an 'idle mixture adjustment...' If I'm not mistaken, all it does is adjust the fuel mixture at idle [with the throttle body fully closed - - or, your foot off the gas...].

it doesn't adjust your cruise mixture... unless you're cruising with your foot off the gas pedal

well, lean out your idle mixture adjustment and check your AFR's at 6K rpm, let me know if their still in spec, or if your rings are cracked.