Well Im back again, I am spinning my wheels here, my idle is still surging up and down, Im kinda pissed cause I just put a new IAC Valve on a couple months ago, $290 bucks of new. One thing that gets me closer to a conclusion about it, is that when it is "surging" i can unplug the IAC and it will idle smooth at about 700, where it should be. Would a thermostat being stuck open cause this, I have bled this cooling system for about 30 minutes too, but the bleeder screw all I got was coolant coming back out, so I dont think there is a problem there.

Now the number two which is really driving me insane. I still have this Shudder under Acceleration which I found a new Throttle Position Sensor and put on it this morning, which I was sure would fix it, but nope, two hours I will never get back was spent working on my car today.

I hope we can come to a conclusion cause I am tempted to just take it to a frickin dealership, which I really really dont want to do. But I am going to replace my IAC again since it should still be under waranty.

 

Could your injectors need cleaning? Maybe time for a new fuel filter perhaps?

 

How's the EGR ports?
After you replaced the IAC, did you reset the comp? Did you let it learn idle again?

 

Have you tried adjusting the F I T V To help the idle surge?

Mid range stumble at around 1500-2000 rpm could be EGR ports plugged up.

http://www.freewebs.com/hondadude/95...5AccordEGR.htm

 

FITV for sure. Did this to mine after hearing the surging idle for nearly 6 months and haven't dealt with it since.

 

High Idle speed and Fluctuation troubleshooting

Leaking EACV- Disconnect EACV connector. Idle speed should decrease. With the connector disconnected block the hole in the intake port or pinch the hose from the air cleaner to the EACV. If the idle speed decreases the valve is leaking. This condition will not set a code. The ECM can only detect an open or short circuit. It also may clog it’s screen if it has one.

Leaking IAC- (Idle air control valve) Disconnect IAC connector. Idle speed should decrease. With the connector disconnected, block the hole or pinch the hose to the IAC valve. If the idle speed decreases the valve is leaking. May not set a code and may not be a codeable circuit on all models.

TW or ECT sensor- (engine coolant temperature sensor) voltage should be about 3.0 volts @ 60 deg F and between .55 & .7 volts @ normal operating temp. If the voltage is above .8 volts at normal operating temp, will cause rich mixture and high idle speed. May not set a code because it is not far enough out of its operating parameters. **Also this sensor will not read temperature correctly if coolant is low. (beware)

Vacuum leaks- a loose vacuum hose or leaking intake manifold gasket can cause high idle speed and/or fluctuation. Also check for bad PCV valve.

Fast Idle Valve- (if equipped) a fast idle valve that is sticking can cause high idle speed and fluctuation. Check it by removing the steel cap on the top and putting your finger over the hole in the middle of the seat under the cap or block the port just inside of the throttle body opening, when the Idle is fluctuating or staying high. When the engine is warm this valve should be closed. You can tighten the seat but it will also change the idle speed warm up values (closing).

Throttle valve- throttle position sensor voltage should be .5 volts with the throttle closed. Make sure the throttle valve is fully closed and voltage is within spec.

ECU-If all else is good, if you reset the ECU and the problem goes away temporarily, the ECU may be defective.

Verify that the cooling system is full of coolant and
there is no air in it.

Remove the air boot from the throttle body and cover the
throttle body with something that will stop the airflow
(your hand, tape) with the engine running. With the
throttle body covered and no air going into the engine, the
engine should stall. If the engine does not stall, look for
a vacuum leak. With the engine running and the coolant
temperature above 90 degrees F, verify that there is no
vacuum on the lower port in the throttle body. If it does
not lose vacuum, look for a faulty fast idle valve on the
bottom of the throttle body, as long as the coolant hose is
good and hot.

Verify that the base idle screw was not turned way out on
the top of the throttle body. If it was, set the base idle
and see if the problem still occurs.

The upper port in front of the throttle plates feeds the
Idle Air Control (IAC) valve and the base idle screw. If
the IAC is unplugged and the base idle screw is turned all
the way in and there is still airflow through the upper
port, check for a stuck open IAC valve.

 

Accelleration problems are usually bad plug wires or weak ignition coil or lean fuel injection but lean injection should show up at high speed with small accelleration.

Take off nice and slow, if you dont have any problems then at night time, open the hood in a dark area and have a trusted friend brake torque the engine and watch the spark plug wires for arcing or a blue haze around the wires. Hopefully it will misfire while you are standing there.

You do have an automatic?

 

Same issue with the shuddering & I cant find the answer.

 

Mine is a 5-speed.

Now I had not quite a breakthrough today, but The two holes in the throttle body (the upper going to the IAC valve and the lower to the Fast Idle Thermo valve), I read somewhere that the lower hole when the car is running there should be no suction, or very very little. Mine has adequate suction. (Its more than very very little in my opinion). Now I took the Fast Idle Thermo valve off and too the end plate off and found that the wax collar that holds the plunger in place was loose, or unscrewed. I used a pliers to screw it back in, I did not mess the wax collar at all when I screwed it back in. But now that did not help my idling problems when I put it all back together though, but I am assuming now that the Fast Idle Thermo valve is indeed bad since there is suction from the small hole in the bottom inside of the throttle body.

Im gonna try to tune-up this thing this next week hopefully I will get paid, Im gonna put new plugs, wires, pcv valve, distributor cap and rotor button.

 

Posted this reply in your other thread before I saw and read this one......

 

Well my coolant level I think is ok, after I put the Fast Idle Thermo back on after screwing back in the Wax collar, I bled it for 30 minutes, the bleeder screw right behind the EGR valve had no more air coming out of it, and the Temperature Guage has been between the 1/3 mark and the 1/2 mark, never going past 1/2. I did read that that temperature reading was normal or around normal, and that was the same as its been when I bought the thing 14,000 miles ago when the idle was where it should have been, not to rule out your help, as I will try to bleed it again tomorrow, but everything seems to be good with the coolant.

I have indeed replace the IAC valve as well, it is only two months old being on it, the old one did have a lot of debris on the screen on the left opening of the valve, and after cleaning the screen of debris, it ran good for a while, but not even a week, so thats when I continued to replace the valve.

 

Now I was able to fix the acceleration by a new cap and rotor, plugs and wires. Thats it. I too was told that it had been tuned up before I bought it, but it wasnt. Ive read that on some other people's posts so, just be wary.

The Surging idle which was driving me insane for three months has been fixed. I was out tonight looking at the car, seeing if I could do anything. It never occurred to me that the idle was higher than it should have been, it idled at 1600 rpm. What I did was just turn the idle screw out, which is on top of the throttle body. Screwed that out and put some loctite on it and whala, it idles where it should at 600 when warm, and when its cold right at startup it only goes up to 1100 now instead of 1900!

I hope this helps out a bit for anyone else!

ClarkS40