Problem:
there is whistling coming from the throtle body. it's very loud and the noise is annoying. I think it NON-electrical.

Symptoms:
does it during a load at between 1/3 and 2/3 throttle
only while driving. goosing / reving does nothing

What was done to narrow it down:
2 EX TB's and 1 first gen, 1 2nd gen crx si TBs. i have gone though.
taken off each vacume thing (tubes, sensors, etc) that could whistle when driving. nothing works.
there was a few tares in the intake hose so i patched those.
took out the idle screw compleatly and it still does it only under the above thortle.

Problem began after I:
MPFI swap and ajusting the idle.
been doing it over a month. and i'm fed up with it.

 

Had the same problem when I went MPFI. Its a whistle sound and only happens for 2 seconds under load. Almost sounds electrical.

I switched out my pepboys cone filter for an AEM one and it went away.

 

it dosent happen for 2 secs. it's continuos. and i'm runing a stock air box w/ amsoil filter.

 

Usually the whistling has to do with the idle screw, at least from my experience. Adjust the screw a little in or out and see if it stops...but seing has how u said u completely removed it, i dont know. Maybe tighten it up??

 

mine does the same thing on my dohc zc and i am running a j's racing chamber intake.

 

did u get this right after mpfi swap b.c I did

 

yea duh, didnt read all of post just posted but yea dude SAME EXACT THING is goin on with me, glad someone made the thread.

 

i had this both times i changed peoples intake manifolds to mpfi what it was 4 me was how i tightened the intake mani down. try tightening the mani down more and get all bolts even the middle one thats hard to get to

 

mine is doing the whistling thing to but is an SOHC ZC it's done it ever since i installed it in my ef9 i figure it was normal but now i don't know since im reading this thread

 

its the idle srew on the throttle body(bisk or somthing) its from the air being sucked into the intake and the throttle body butterfly pushes the air against the top of the inside of the throttlebody where there is a little hole that is acuatlly there to allow idle when your not on the gas. the air getting sucked past the hole makes a wistle if the idle screw is messed with.

your not suppoed to adjust it becuse the idle is set by the ECU, the screw is set from the factory on a flow bench and adjusted for that throttle body specifically. thats why there is usually some paint over the screw... cause your not suposed to Fu#$ with it.

I used to mess with them to adjust the idle after i swapped motors, you dont have to. Just let the car sit and idle like **** for a half an hour after you reset the ecu, and it will learn idle.

to fix your screech
turn the screw back in a little(not all the way, or you cant idle) and drive it, slowly adjust the screw until the squeal goes away. your idle will be really low at this point. But now that you have your squeal gone, take out your hazard fuse for a few minutes, and let the ECU reset. Then put it back in and start the car. it will idle weird for a while, but dont touch it!!! let it learn idle. if it dies start it, and let it sit there and learn idle by its self.

there now youve fixed throttle body squeal and you know how to let the computer do the work for you

 

ok i'll try that.

as it is right now the idle is wicked low. the battery light flashes realy fast after goosing it. so i would guess 400-500. is this the computer re-compinsating? or?

 

Did you reset the ecu yet, or just turn the screw in? The idle shouldnt be that low. i believe normal idle on a manual trans is like 650~750 thats usually wherer i like mine.

you might have other problems, like a vacuum leak. I know it sounds backwards, but if you have a vacuum leak that would usually cause high idle, but if its a big one, then the iacv will go crazy trying to compensate idle and it will go way low. check all your vac lines, and the throttle body gasket and IM gasket. also check the vacuum line to the FPR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EFbomb &raquo;</TD></TR><TR><TD CLASS="quote"> take out your hazard fuse for a few minutes, and let the ECU reset. </TD></TR></TABLE>


The ECU fuse just might be more effective.

 

i have the same whistle noise on my sohc zc, i will have to try messing with the idle screw since i adjusted it when i put a new tb gasket on thinking the whistle was that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 &raquo;</TD></TR><TR><TD CLASS="quote">


The ECU fuse just might be more effective.</TD></TR></TABLE>

Ya'd think so... but the Factory Service Manual says to remove the HAZARD fuse to reset the ECU. Do it when the car is at normal operating temperature. Remove the hazard fuse for 15 seconds (I usually give it a "30-Mississippi" count just to be sure), replace it, start the car WITHOUT TOUCHING THE GAS PEDAL, and let it idle for 5 minutes or so, and the ECU will reset itself.