Without air pump..
 

Hey everyone,
For you guys that you removed the air pump, did your FD idle lumpy or is just my car.
If yes what did you do to make it idle normal again? Will a resistor work?

Before I removed the air pump sometimes the connector would come off and the car would idle like crap so I put it back and it would idle superb.
Now I removed the pump completely and for over 2 months still idles crapy.

Any help/Idea appreciated ;)

yeah i've had the same problem for a while now too

Without the air pump it will idle poorly. You may be able to fix that by removing the ACV. Mine idled poorly (but never threatened to stall) after I removed the air pump. The car had not had cats. on it for some time, and I wanted more room under the hood. When I installed the Power FC (removed the PFS PMC) it fixed the idle. Runs fine now (well, not now, it's -16 C out and the car is on jackstands, but when it's not winter...) ;) .

The Air Pump has to do with the recirculation of the exhaust gases back into the intake, and if you want the lumpyness to dissapear you have to remove all the smog crap... and replace it with block off plates, so that your air fuel mixture is correct at idle...

I decided that that was too much troubble especially since I'll need it every two years, and it's just easier to loose a couple of HP, than to pay / install it every few years...

interesting, I should keep this in mind since I'm removing mine soon :) Perhaps thats why my idle is jumpy at times since I disconnected my air pump

so anyone know how many HP is gained by removing the airpump???

You dont gain any hp, or any benefits of removing it on the stock ecu or stock cat. The only minescule thing you could pull out of it, would bet its one less pully to turn, and 10 pounds less weight.

Which is drag on the engine, especially if the clutch engages and the pump is in operation... so you are loosing hp, just not a whole lot... A guess would be less than 10

Insignificant, especially since it shuts off after 3250 rpm; not exactly an engine speed where you're looking for every last ounce of horsepower...

also when removing the airpimp dont you run into problems with your water pump pully not having enough belt tension on it?? i wonder why the air pump removal is so popular? i would only do it if i could fabricate a dummy pully that just spun in its place... belt slip on the water pump is MUCH more of a concern than an extra 10HP.... but i really would like to save 10lbs up front!!!!!

Well, all the smog crapp is gone same time as the air pump.

I did it mainly to make more space and simplify stuff under the hood, horspower gain I think very minimal or maybe even nothing.

I realized that the water pump belt must be very tight since the contact to it is not strong, the belt is almoast direct and if litle water goes on belt it will slip easy and the pump will almoast stop and that's not something you whana let happen.

If you are concerened with belt slip = get smaller belt. :) have a nice day.

I have wondered that the last two years. I always get lowers weight and simplifies. IMO, it doesn't really simplify anything as it is easily removed for any repairs. 10 lbs is 10 lbs, I guess.

You have to have a programmable ecu to fix the idle after removing the air pump (PFC, PMS, AEM, Haltech, etc).

I have a pettit remapped ECU so is basicaly the same as stock in that matter .

hmmm, not really. you have to see a diagram of how the belt runs without the airpump to understand why it will slip VERY easily. i saw a diagram a few days ago but cant remember where i saw it. anyway, has anyone tryed a dummy pully in place of the airpump? that would kinda ruin the extra space made in there though. in my particular case i need all the room i can get, as well as all the weight savings i can get, but i wont sacrifice overheating my motor... so im still undecided.

A smaler belt than 300mm wouldn't probobly even fit.
There is no reason to put a smaler b/c the 300mm fits perfect and the altenator has enough room to tighten it as much as you want.
All I'm trying to say is make sure you tighten that sucka good.

Disconnect the wire, the pump won't turn on, and your pully is still in place, the clutch won't engage so you won't have HP issues... but unless you dismantle the rest of the smog BS you will have idle issues... I think the Greddy or Unorthodox pully kits come with belts and pullys that illiminate the airpump and don't cause issues, and add some grip to the water pump surface, as I recall for the belt to catch on (traction)

So I guess no one tried the intalling a resistor in the air pump connection line to bring the idle to normal.

I'm gonna go by a resistor and se if it will fix that crap, I'l keep ya posted...

Maybe you missed above when i said that the all the smog crap is gonne.
Even before I removed all the stuff I did a test by disconecting the air pump with all the smog stuff on it and would still idle crappy, sometimes the air pump would disc. by itself and I would know right away that it got disconcted b/c the idling would change alot.

Why do you think that would do anything? It won't. The ecu sends a signal to turn the air pump on for idle and low revs. The ecu expects that air to be pumped into the intake tract. When it isn't, the car will run richer than optimal. It doesn't matter if you put a resistor there or not, the ecu expects the air to be there, period.

I though if I put a resistor the ECU will think that the air pump is present and idle will stabilize.

ok, well now you are layring problems on top of your idle problem. it has taken me 8 months to fix my idle problems because there were multiple causes. i would not suggest removing all the smog stuff UNTILL you fix the idle. otherwise its just another variable. but it sounds like its all gone already, so tell me about your idle. what does it do? in the last 8 months my idle has gone from 1800-2000 rpm racing idle to a beautiful/healthy 750 rpm idle. i can share what exactly has been done to the car, and what my symptoms were if youd like to know. my car now accelerates harder, my secondary does not have a mushy transition anymore, it boosts harder, bla bla bla and this is without any mods done to the car... just fixing it properly :biggrin: -heath

When I first start the car (cold motor) till warms up it idles to between 2.5-2K rpm as it warms up, compare to bridge ported motor, than after fully warmed up idle still goes up and down but much slower up-down retual, it jumps from .65/.75-1Krpm constantly, when I use the lights at night it jumps less almoast perfect idle.

yup! that was my exact problem!!!!!! but mine was 1800-2000... yours is very low!!! possibly because of removing smog stuff but you said it was like this before? ok, you most likely have a vacuum leak, either in the vacuum lines (have they been changed recently?) or your intake gasket, or something along those lines. for me it was the vacuum lines AND intake gasket... i thought it was just vacuum lines at first so i only did the lines... then i had to re-do everything when i did the intake gasket. that brought my idle down to 1400 steady. then the throttle cable, and idle screws were adjusted (i had a shop do this part...they charged 250) and its now at 750.

any other symptoms? im wondering why your idle is so low? did you fiddle w/ the idle adjustment screws? it may be that all the throttle stuff is working right.... you might just have a vacuum leak. doing the vacuum lines is not for the faint of heart... and the intake gasket isnt eather (the turbos have to come off). im willing to help w/ questions, as well as everyone else here, since ive been through it before... so if you decide to do it let me know. -heath