just wondering...so many threads on this that just digress off in a million topics...

 

Definitely, there is no provision for the Idle Air Control Motor to set a code.

P

 

Okay I've done a CRAP-TON of research and PM bothering to find out how I can get rid of my slight plusating rough idle and faint clicking/sputtering sound while accelerating...

This weekend here's my checklist of things to do before I go postal...

1. Burp/bleed coolant from both thermo valve and radiator cap
2. Check all vacuum lines for leaks (man this seems almost impossible to do w/ 100% accuracy)
3. Seafoam that sonofabitch
4. Change the oil myself and top off all fluids
5. Change spark plug wires w/ new NGK OEM ones (plug wires & coil wire)

Any other suggestions before I start buying valves, O2 sensors, etc...?

 

The SeaFoam is a good idea. Not so much for the carbon it will remove, but for the cr...p and deposits it will remove when it's injested thru the Throttlebody. With any luck it will clean the Idle Air control Valve as well.

P

 

Well just did the seafoam to see how that would affect it...I'd say, if anything, it made the idle a little worse. I want to say acceleration/response felt a tiny bit better, but the idle now surges a little more than it used to...

After car warms up (or before, really makes no difference) and I come to a red light the idle sits a hair below 900 rpm. It will sound perfect for approx 1 second then drop a hair for about a half-second then it seems to overcorrect by a hair in the opposite direction for a half-second then settles back to 900 for one second...loops like that over and over....quick little loop of steady/drop/raise/steady

The total amount of surge/drop is less than 50 rpm total (+/- 25), but the mother shakes quite noticably even with all acessories off. I'm worried it's just shaking **** loose all over the car.

I sprayed carb cleaner in the PCV valve (that's the one coming out of my valve cover, right?) and that didn't help any either. Cleaned the ICV but it only helped a little. I'm almost positive the sputtering during acceleration and the pulsating/rough idle are related. I'm hoping the timing's just off by a tooth...what would that feel like? Also, if the belt's on correctly, could it be the positioning of the distrib or would it be a dirty/broken distrib? And what about a valve adjustment? Thanks for the reply bud.

 

Thanks for the kind word, I try to be helpful.

One thing I want you to pay particular attention to tomorrow:
Does this idle surge you speak of correspond to heavy electrical loads kicking in (like cooling fans, etc)??
I've seen momentary, rythmic rpm drops (accompanied (ouch) with a momentary shudder). It's caused by the alternator going into "Oh, My G.d" mode as it compensates for the sudden increased electrical load, and this equates into load on the engine

P

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">Definitely, there is no provision for the Idle Air Control Motor to set a code.</TD></TR></TABLE>So then what's code 14 all about?

But I think the answer is yes, it can be dirty & sticking some, or even clogged for flow; but not screwed up electrically.

 

Replace the IACV with Honda factory part and reset idle.

 

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.

The idle fluxes due to the fuel control programming built into the ECU, it notices that the engine is going too fast and that there is no VSS signal to the speedo, so the ECU cuts the fuel to the injectors to eliminate a higher than normal idle speed since the vehicle is not moving. Once the idle drops to a predetermined level the fuel injectors are turned back on and the vicious cycle starts all over again.

If there is air in the cooling system, it may be trapped at the engine coolant temperature sensor and the computer does not know what the coolant temp is but it knows that the engine bay is hotter now and that the O2 sensor is working so it goes bananas trying to keep things going, air may be trapped in the idle control valve, the one with two black small rubber hoses going in and out of it, there is also a screen in there that tends to get dirty and plugged, I have seen pics on H-T before of the parts break down but it didn’t show this screen with the rubber O-ring type gaskets, it is available with the O-ring kit here in Japan.

 

damn Duane in Japan...thanks for the article! That's a lot of good info...I will definately incorporate it into my checklist of things to look for. Also, I will be sure to update this thread with results of my efforts!

thanks again

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pbink &raquo;</TD></TR><TR><TD CLASS="quote">...how I can get rid of my slight plusating rough idle and faint clicking/sputtering sound while accelerating...</TD></TR></TABLE>

May or may not help your problem but when was valve lash last adjusted?

 

vavle adjustment could have been 10 years ago for all i know...service records are supposedly around somewhere, but my relative can't find them

 

That'd be the first place I'd start. Pop the valve cover off and check them out (on a cold motor, let car sit over night). Have new VCG and tube seals handy. Pull out the plugs so you can turn over the motor by hand via the crankshaft pulley. A set of feeler gauges, 19mm socket, a 2ft extension bar are a must. Everything else is found in the common toolbox. This is an easy job, we can all provide you with more detailed info if you are really interested in doing it.

 

I actually plan on doing that this weekend...thanks for the help...

Okay 'nother update...

Today I wanted to get all the seafoam outta my oil from yesterday's engine cleaning, so I changed the oil/filter. I put brand new NGK plugs, topped all my fluids off, and put on a new PCV. While I was under the hood, I checked all the distrib connections by just pushing on them. I dunno what exactly did it, but now my engine idles 100 rpm higher (@ 1000 +/- 100 which makes it shimmy less) and the pulsating surge is basically gone. I had the new plugs in there before the seafoam and oil change (oil had been changed recently anyways) and the idle was way rough and surgy, but the combination of new plugs w/ seafoam treatment, oil change immediately after, and new PCV seemed to have gotten rid of the surging almost entirely. I did use 5W30 and have no idea what the old oil was...maybe the thicker oil could that have raised my idle by 100 rpm?

BUT...that idle's still too high (would like the stock 750 +/- 50) and I still get the clicking/muffled thuds while accelerating quickly. While she was idling, I got out and put my hand in front of the tailpipe and could feel a steady rythmic exhaust pressure, but every couple seonds it would miss one and then fire two quickly together, out of sync...then run normal for another couple seconds.

Tomorrow I'm going to get a timing light and make sure my pointer is at 15 degrees +/- 2. If that's fine, I'll do a valve adjustment. I'll also take off the distrib cap, but I'm not quite sure how you tell if it's bad or not. I wish I had a voltmeter so I could check the plug wires, but if wishes were fishes...

Again...thanks for all your help!

 

has anyone had their spark plug wires go bad before replacing them? I'm assuming that bad wires would translate to misfires, correct? Same with distrib, causing misfires is the only thing i can imagine bad ignition parts could do. Is it even possible for ignition timing or motor timing being off by a hair to even cause misfires? (if that's what I'm hearing along with the clicks).

Also the clicks aren't at every speed and every level of acceleration...just at certain pressures and speeds...if the valves were outta whack wouldn't they click at every speed, even while cruising?

Also...a friend told me about a condition he heard of in hondas where the crankshaft becomes loose late in the life of a honda...is this probable or even possible?

 

What kind of plugs were you running, and were they in good/bad shape? How about a new cap and rotor? Throttle cable sticking a little maybe? People have also been known to bump the idle up to fix an idle problem, instead of fixing the problem at its source (normal car maintenence, tune up type stuff).

Another thing, your cat is probably rottten by now. Clicking could be pieces of expired catalyst rattling around like a tin can. If its plugged your car is probably all constipated.

You may not hear your valves at all times, especially over normal engine noise. My best suggestion is, if you don't know when the valve lash was last adjusted, it's time to adjust them.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pbink &raquo;</TD></TR><TR><TD CLASS="quote">a friend told me about a condition he heard of in hondas where the crankshaft becomes loose late in the life of a honda...is this probable or even possible?</TD></TR></TABLE>

I believe he's talking about the crankshaft pulley, see item 18:



The rubbber in the middle that bonds the 2 pieces of pulley into 1 piece can eventually rot, slip, and create problems.

Start taking things apart buddy, welcome to 15 year old car hell