HELP... my RPM fluctuates like crazy when I am idling. It is the same with and without the aircon. This happened after I reduced my idling speed with the idle screw because my car would idle at 1500rpm at the lights. Only byu blipping the throttle can it drop to 1000rpm. Now it is set at 900rpm but the idle goes up and down violently and the car dies at the lights at times. What could be the problem. I have checked the IACV and the mesh is clean. Is there a FITV valve on the ITR manifold? I can't seem to find it. I was thinking the plunger might be loose but I can't even find the plate on the FITV(suppose to be located under the throttle body). My cams have been advanced. Can this fluctuation be caused by having too much of an advance.

 

stock car? ECU?

 

Dont mess with the idle screw. Sounds like you might have air in the coolant lines.

 

There isn't a fast idle thermo valve on ITR throttle bodies. Maybe it's a TPS calibration problem?

Air in the coolant lines wouldn't be a direct cause because teh IACV doesn't rely on local temperature feedback to determine idle speed. The ECU determines idle speed as a function of coolant temperature. There would have to be a lot of air in the cooling system for it to affect the idle speed. Regardless, check the coolant level and bleed the system as you feel necessary. Generally, if the coolant level is topped off, then it's probably not going to be an air bubble.

 

What all have you done to the car recently? Messed with the TB or IM?

 

I have just changed my coolant and bleed it in the process. The previous coolant was rusty. Since that didn't help much, I adjusted the idle screw and the idle dropped. Now I don't idle at 1500rpm at the lights, but at around 1000rpm. If I were to adjust the idle to about 800+rpm, the RPM would fluctuate alot when I come to a stop at the lights. If I were to blip the throttle at idle, the RPM will start to fluctuate continuously. So I have managed to solve the high idle problem, but the fluctuation is bad. I have not messed with anything else.

 

A vacumme leak can cause idle surge..Check the lines.

If I remember correctly a bad 02 sensor can cause this as well.


-Dan

 

He should throw a code for bad o2.

Take your radiator cap off, start the car, let idle until the fan kicks on while pouring more fluid in as necessary.

 

There's no code thrown. I did recall toping up the fluid after bubbles surfaced. But I can't remember if the fan kicked in. Will that make a difference?

 

check the pcv hose

 

I just had a new discovery on the problem. It seems to fluctuate slightly less when i release the brake padel at the lights. Could it be the brake master vacuum hose?

 

check it! When stopped at a light, pressing and de-pressing the brake will make the rpms fluctuate slighty, but nothing out of the norm. Have you re-bled your coolant? Its not hard and doesnt take long.

 

how does coolant issues effect idle?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW DC2R &raquo;</TD></TR><TR><TD CLASS="quote">how does coolant issues effect idle?</TD></TR></TABLE>

From my own experience, having air in the lines can cause surging or fluctuation of RPM's. I would guess that air going thru the IACV would cause it, but could be wrong. However, I have experienced this from only coolant.

 

Alright, I am also experiencing some other problem which I posted in another thread. "I'm getting this jerking and hesitation when the car is in motion whenever I release the gas or step on it slightly. This occurs in any gear but not all the time. I am guessing that it happens whenever I go over uneven surfaces, since it will happen almost instantly after the uneven road. Could it be a faulty knock sensor? What are the tell tale signs of a distributor about to be broken?"

I am about to change my spark plugs to see if it helps. I hope the plugs can solve these 2 problems at the same time even though I am not keeping my hopes up too high. Will get back to you guys.

 

Have you had the valves adjusted recently?

 

I had a similar problem w/ the idle bouncing like crazy. I ended up changing the IM gasket and problem fixed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Big Phat R &raquo;</TD></TR><TR><TD CLASS="quote">stock car? ECU?</TD></TR></TABLE>
^^

 

and about taking your foot off the brake... it's like anything else, when you roll up the windows the rpms will jump a little, when you turn on your headlights same thing... and same thing when the brake lights turn on. when you use power/lights ect. it will cause rpms to fluctuate slightly, that's normal...

try what R1366 did and change your IM gasket

 

Okay, I just replaced my plugs. The car seems to idle slightly better but it still bounces. At the moment I have only driven the car twice since the change with no jerking problem. Will continue monitoring. But the car does feel slightly weaker with the stock NGK Honda plugs ZFR7-11. Previously it was on Iridiums. The car came with a plastic manifold gasket installed. Is there another layer of stock gasket?

 

Okay, I have not encountered any hesitation since the plug change. But there is a new problem now. There is a CEL thrown which blinks really fast and from my estimate, it is about 6 to 7 blinks. This occurs during full throttle and the occurence is random regardless of speed and gear. The car also feels weaker from before after VTEC. About a week before, the power started dipping after my car alarm went mad and went off when I tried to crank the car. This caused a loud repeated ticking sound like that of a thermostat coming from the ECU which lasted for approximately 15 seconds. I don't think my Apexi Power FC is fried as I am still able to drive the car. Will the car still start and run if my Power FC was reset by the whacky alarm incident? I see some settings in the Power FC maps, but I am not sure if its the stock settings. Any Power FC user who can help me here?