hey everybody,was wondering if anybody could help me w/ the idle problem....when the car is fully worn up,it'll start to idle up and down....bout 800-1200 rpm...id check for vaccum leak,low radiator fluid,and clean the idle control valve and it still doing it...so any help from you guys will be nice...

 

its started doing this after i change the thermostat...its a gsr and i put a b16 thermostat...not sure if its the same for both motor....dont know if i need a new idle control valve thingy...how do i check to see if i need a new one?...

 

Sounds like it could be either the IACV (idle air controll valve), or you collant temp sensor. Check those out and get back to us. And are you getting a CEL? (check engine light) If you are then find out what code it is.

 

no, i dont have any cel...but how can i check the idle air controll valve and the collant temp sensor if its bad?...but my temp looks fine.i mean it get fully warm up in 10-15 mins....i see bout 195-200 degree on my autometer gauge....it doesn't do it when its cold,it only does it when its fully warm up....

 

I think your idle is adjusted too high. Unplug the IACV and adjust the idle down to about 450 to 550 RPM . Plug the IACV back in and clear your code. If a vacuum leak or excessive idle bleed allows the engine to exceed 1000 to 1100 RPM and the throttle plate is closed, The ECU shuts off the injectors. This starves the engine, the RPM falls below the threshold, the injectors cut back on and the whole cycle starts all over again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">I think your idle is adjusted too high. Unplug the IACV and adjust the idle down to about 450 to 550 RPM . Plug the IACV back in and clear your code.</TD></TR></TABLE>

hows that,when its fully warm up it idle at 800 rpm and then start to go up and down...and like i said there is no cel or codes....before i change the thermostat it was idling fine until i change the thermostat...i havn't adj anything on the idle screw thingy....first i thought it was low coolant fluid but i let the motor run for 30 mins or so and the fluid stays the same....and then i drove it for 3 days to see if the coolant was low or drop any but nope its still the same level...

 

I added a little more to my previous post evidently while you were typing your response. Have you bled the air from the coolant lines through the bleed screw?

 

yes...the one before the radiator hose on top right...i bleed it until the coolant starts to come out....

 

And you did this with the radiator cap on, right?

 

yeap....i did it one time w/ it off because i had to let some fluid out to get all the air out of the lines and added some in...and i did it w/ it on and got all the air out...

 

Then I stand by my original post. It would take you 2 minutes to unplug the IACV and check your idle speed. You didn't accidentally knock loose a vacuum line while changing the thermostat?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">Then I stand by my original post. It would take you 2 minutes to unplug the IACV and check your idle speed. You didn't accidentally knock loose a vacuum line while changing the thermostat?</TD></TR></TABLE>

nope...all i did was drain out the coolant,loose the lower radiator hose,unplug the sensor plug and the ground wire w/ the 10mm bolt that is bolt on top of the thermostat housing,unbolt the 2 10 mm bolt that hold on the thermostat housing,and then took out the thermostat....when i put it back in, i put it in w/ the hole thingy on top of the thermostat on top...and then put everything back in...then id pour the fluid back into the radiator...and then bleed the lines....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">. It would take you 2 minutes to unplug the IACV and check your idle speed.</TD></TR></TABLE>

and how do i go about checking my idle speed?...

 

Does your car not have a tachometer?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">Does your car not have a tachometer?</TD></TR></TABLE>

yea it does...

 

With the engine warmed up and running unplug the IACV. Screw the Idle bleed screw in until you see 450 to 550 RPM. Plug the IACV back in. Turn the engine off and clear your code. I would try for 475 to 500. Sometimes people just start screwing in the idle screw 1/4 turn at a time until the problem goes away.

 

is that the screw on top/front of the throttle body or the one underneth it?...

 

Looking toward the throttle body with the TPS on the left and the throttle lever on the right, the screw is facing you on top of the bore. Sometimes it has a wax seal. If it doesn't have this wax seal it can vibrate out and increase the idle over time. If you adjust it, it's a good idea to put a dab of silicone in the recess to keep it from vibrating out again.

 

well, i went out and done that that you told me and it still doin it...so i might just get a new idle air control valve...and go from there...

 

does it do it with the IACV unplugged? I have never seen one go bad. They just get dirty. Did you remove it and spray it out with choke cleaner and make sure the screen was absolutely clean? If you remove it, make sure the coolant passage is not blocked. You know, those lines are passive and prone to holding air. Feel those lines while the engine is running and warm and see if they feel hot enough to have good circulation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">does it do it with the IACV unplugged? I have never seen one go bad. They just get dirty. Did you remove it and spray it out with choke cleaner and make sure the screen was absolutely clean? If you remove it, make sure the coolant passage is not blocked. You know, those lines are passive and prone to holding air. Feel those lines while the engine is running and warm and see if they feel hot enough to have good circulation.</TD></TR></TABLE>

yeah i unpluged it and it stop...but i havn't take it off the car to clean it...

 

YES IACV's do go bad. I was having this similar problem, idle was surging from 1200 - 2000 rpm. Cleaned out the IACV several times but did'nt do anything. Finally swapped out the IACV with a good working one and VOILA!! No surging, idle's like a kitten.

 

Try checking the fast idle valve. I have a gsr and it did the same thing. Look directly under your throttle body and there should be like a cylindrical type thing with 3 or 4 10 mm bolts screwing straight up. When you get this off take the two screws out of the end of the valve. the screws should hold a flat plate on. then you should see a white valve on the inside with a spring loaded nipple in the middle. screw the white valve surrounding the nipple all the way in until it stops. this should at least eliminate that theory.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by persianprelude &raquo;</TD></TR><TR><TD CLASS="quote">YES IACV's do go bad. I was having this similar problem, idle was surging from 1200 - 2000 rpm. Cleaned out the IACV several times but did'nt do anything. Finally swapped out the IACV with a good working one and VOILA!! No surging, idle's like a kitten. </TD></TR></TABLE>

yea i just bought a new iacv today, so when i get it hopefully it'll take care of it

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by puffsef &raquo;</TD></TR><TR><TD CLASS="quote">Try checking the fast idle valve. I have a gsr and it did the same thing. Look directly under your throttle body and there should be like a cylindrical type thing with 3 or 4 10 mm bolts screwing straight up. When you get this off take the two screws out of the end of the valve. the screws should hold a flat plate on. then you should see a white valve on the inside with a spring loaded nipple in the middle. screw the white valve surrounding the nipple all the way in until it stops. this should at least eliminate that theory.</TD></TR></TABLE>

havn't thought about that before but will def try it out tomarrow...i will take any chance of mixing the damn surging...

 

I have done ALL of these on my car... And I mean ALL! The only way I can get my idle to stay constantly is if I squeeze the line between my PCV and the IM itself? But i've replaced the PCV, used a bolt to block the line from the IM to the PCV, yet it will surge? The only thing I have yet to do, is try resetting my idle speed in case it is too high?