mazdaspeed7

Wire it like I did so its at 1500 rpm, then adjust the idle down with the idle screw on the tb, and then the throttle stop adjuster if you need to.

Leetheslacker

if i wire it, itll bounce all around 1500. and bounce around 2k when its cold.



the throttle screw is all the way in, and its still doing this.



and i cant find a vacuum leak anywhere.

mazdaspeed7

Vacuum leaks dont cause high idle in mass air equipped cars, just makes for a shitty idle, or it wont hold an idle at all if its a bad leak.



The hunting idle is from the idle mixture being too lean. On S4's, you have the idle mixture screw which may help it some. I always had S5's so I never got to see how much that could really help it. But you have to get the idle down below 1k rpm, or you wont be able to get it smooth on the stock ecu. The throttle stops are adjustable, its a set screw with a lock nut. I removed the secondary one completely, so the plates would close completely. On the primary, loosen the lock nut, and back the set screw out until the idle gets to where you want it, then tighten up the lock nut. If that isnt enough adjustment, as was the case with mine, put a drop of epoxy over the bleed hole in the primary throttle plate.

Leetheslacker

mixture screw doesnt make any change.



wouldnt a vacuum leak cause the idle to jump as it makes a lean condition?

RONIN FC

Thats a TPS issue, but you cant set it til you bring the idle down. Check the dashpot, they stick sometimes.

mazdaspeed7

A vacuum leak would cause the idle to be lean, because the engine will be taking in air not accounted for by the AFM. On a speed density EMS, the ecu will read the decrease in manifold vacuum and compensate with more fuel, resulting in a high idle. In mass air equipped cars, the afm tells the ecu there is less air coming in that there actually is, resulting in a lean condition. Being lean will not result in a high idle unless it was overly rich to begin with. Mass air cars usually wont hold an idle with a vacuum leak, or if they do, it will be low and unstable.



Adjusting the tps will fix the hunting idle, provided you dont have a very agressive port. On my big SP, i couldnt get a smooth idle on the stock ecu regardless of setting the tps or anything. After putting on the MS, I had to make the idle way rich to smooth it out because of the agressive porting. But to set the tps properly, the idle has to be down below 1000 rpm. Focus on that first. Pull the TB and clean it if it hasnt been done. Its also a lot easier to get to the throttle stops with the tb off.

ShadowboyM

lee i had had that same problem with mine, i couldnt fix the bouncing idle for nothin, so i just said **** it!!!!! it was fine when i was driving. but when i stopped at annoyed everyone who was stopped around me, but they can kiss my ***.

RONIN FC

Your car should be taken from you...

teknics

so lee you're saying the throttle stop screws are all the way backed out and it still wont go under 1500rpms?



try taking off everything before the afm, then block the inlet part of the afm, see if the car's idle falls.



if not you definitely have something leaking somewhere.



there's no reason with the throttle plates absolutely completely closed that the car would be idling at 1500.



unless the plates are gummed up and not really closed all the way, or someone drilled out the bypass hole in the primary plate to allow for more air.



double check the throttle body....and dont worry about setting the tps until you get it to idle under 1k, adjusting it while its over 1k is actually just messing up the tps setting.



kevin.

Leetheslacker

throttle stop?



is there an adjustment like the TII TB that adjusts where the wheel the cable goes on stops at? cause if so i havent touched that. i'll take a look tonight.

the screw on top of the tb for the idle speed is tightened all the way in if that is what you're referring to.



i'll try taking the filter and adapter off and block it with my hand.



i sooo want a real header and to get rid of eveyr emissions piece and megasquirt the bitch, but im broke as **** right now so im just trying to get what i have running right.



if it makes any difference, the car will randomly run good throughout the revs, and then randomly be kinda slow and stumbly and seems like its missing.

i think maybe the ports are sticking, or somethings just being dumb. or maybe its just it being really ******* cold outside.



***** so goddamn complicated.



i just want to know that my car is running 100% for once instead of always dealing with little problems that i cant figure out affecting how it drives and performs.



and ive been driving it forever with a random shitty idle. like today when its cold it bounces form 2k and up.

going through drivethroughs sucks, they cant hear me. ***** just so annoying.