I am looking for the location of the idle screw on a eg coupe EX. I know its on the intake manifold, but exactly where and how does it look like?

 

umm its the giant goldish screw on the throttle body next to the charcoal canister line

 

Its this true if I have a JDM B16a in a eg?

 

I NEED HELP!

 

pretty much the same for all d and b tb's

 

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

pretty much the same for all d and b tb's</TD></TR></TABLE>

 

you're not realy suposed to touch that.. thats why it painted shut. it you idles out it my be a vacum leak.

 

what you mean? thats the idle adjustment screw... why would you not supposed to adjust it? please... explain

 

Well the previous owner said he adjusted it so it would run richer.

 

hmm, all it does is adjust the idle speed.

 

i lost my screw...i need a new one...hahah...idles fine though....

 

can't you just adjust your throttle cable to control your idle??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93egsi &raquo;</TD></TR><TR><TD CLASS="quote">can't you just adjust your throttle cable to control your idle??</TD></TR></TABLE>

Why would you do that when Honda clearly built in a much easier, more precise way of adjusting your idle speed? I mean, if you REALLY need to get your motor to idle high (don't see why you would), then adjusting the throttle cable to slighty open the throttle plate would be the next option I suppose. But really, you should just use the idle adjustment screw.

 

When you adjust the idle using that screw, you also adjust the The throttle position sensor signal voltage output to the ECU. You can idle it up, but the ECU may no longer "see" the TPS is closed and that the engine is truly at idle. So in turn the ECU will do what is called "fuel cut" and then the engine will idle up and down. DON'T mess with that screw. If you are having idle speed issues, take a look at the idle control valve (IAC) or the fast idle thermo valve.

 

HUH?? the TPS??

I move my screw all the time to help me idle my car fine.....am I messing something up??

 

My B16 is idling at 1800-1900 RPM and I dont know why. Do, I need to adjust this screw? Would it be in the same place on my 62mm BBK TB?

Is it relly harmful? or cause the ECU to read wrong and do fuel cut?

 

I have a 93 JDM D15b - it's a VTEC-E so it's only for low rpm fuel saving and doesn't rev out to 7200 like the standard VTEC's.
Anyway - often when I stop at lights and pop it into neutral the rev's start hunting up and down between 1200rpm and 500rpm - after a few seconds it calms down and sits at normal idle. This doesn't happen all the time but the engine check light has come on a couple of times - but go outs after a restart.
***Question: Is the problem I am having to do with that screw or a sensor on the intake manifold???***

 

If the ECU sees that the throttle is closed (~.45v) and engine speed is &gt; 1100rpm, it will cut off the injectors to save fuel....this is also the reason that when you have a vacuum leak, your idle 'hunts'. Vacuum leaks on speed-density metered engines only serve to raise the idle; i.e. depressing the gas pedal induces a big vacuum leak.

If you held the throttle open with your foot (or the throttle plate stop screw is holding open enough for you), you would not expect that the rpm would hunt around at all...it would stay at a fixed rpm. So when you mess with the throttle plate stop screw, which changes TPS output, you could in fact open the plate enough to tell the ECU that you just want to increase engine speed...so fuel cut is not used in this case, thus there really isn't a problem to the ECU.

So shineyjerry - it sounds like you have a vacuum leak; have you cleaned out your IACV to see where that gets you (could be sticking causing the leak)?

B16CRXT - In your case it just sounds like something is holding the throttle plate open a little too much....throttle plate stop screw perhaps/tight throttle cable?

 

Thanks for the tip. I replaced my IACV tonight with a spare from a B16A - it seemed pretty similar to the one I had. When I replaced the unit I found the rpm's were staying up around 1300-1500 when warm and it was still hunting up and down (i was kinda pissed). I then used the idle screw to bring it down to normal idle (about 2 full turns!!) and all seems ok now. The test will be tomorrow when it gets a bit more driving as the problem was an on and off again affair.

Cheers again

 

this is a great time to visit http://www.helminc.com, and pick up a factory service manual for $70, so you can actually fix the problem instead of just covering it up. dozens of things can cause a rough or erratic idle; you should go through the proper steps to diagnose the problem, and fix it so you can stop worrying about it.

75% of technical questions would never be asked if people would just read that book.

 

OK swapped the IACV over last night and the rpm's are not hunting at all anymore - but the idle has become rough when cold when it wasn't before. I have to admit that I really don't know much so this question might seem stupid - is the spring sensor attached to the IACV called the TPS or throttle position sensor? After watching my mate reconnecting this last night I noticed it moved from side to side altering the rpm's significantly. I am now thinking this was my problem all along - not the actual IACV that I swapped over? Either that or the B16A IACV is causing the rough cold idle as it's now on a D15b motor and it's a slighty different design.
Any help would be appreciated. Cheers.

 

Hey thanks, I have the service manual now - got it online. It's not detailed enough for me to know what the problem is for sure so I'll just keep plugging away. Trial and error is the best way to learn.