I kinda loosened it yesterday, because I wasn't exactly sure on how to disconnec the Throttle Body. Now, it's finally disconnected (woo hoo! btw, got a little coolant leak though, but it stopped).

What does the screw do in the picture? It has a nut on it, and its end is a phillips type.

Anyone? thanks

 

Idle adjust...dont mess with it...

Well, kind of. The ECU controls the idle. But, if you close or open that screw too much, it won't work. That screw is set form the factory. If it is out of whack, the ECU wont be able to control the idle like it's supposed to.

 

This is a mechanical stop which limits the travel of the Throttle Body butterfly valve as it approaches the full closed position. The tip of this adjustment screw is aligned with a tang on the throttle cable guide. On my car this screw appears to be adjusted so it does absolutely nothing.

Turning this screw clockwise could prevent the butterfly from closing completely. That would increase the engine idle speed but is not the preferred means of regulating idle rate.

 

Daniel and mz, I'm glad you replied. I performed the Throttle Body Cleaning, and obviously, I separated the throttle body from the rest of the car. Man! was it full of gunk and carbon build up. A thick layer that I couldn't scrach off with my nail...

anyway, It's all clean now. So I put everything back together, and tried to make sure that adjustment screw I was asking about was back in the right place. I found out the hard way.

When I started the car, It reved to about 2500, and then dropped to 1500, or around there. But it was very unusually high (idle speed, that is.) Well, I put the car in reverse and I felt a major jerk, and I got scared. I didn't really know what to do, so I tried adjusting the idle screw (on Andi's MaxFAQs) but it didn't work. Then I thought about that screw that I was talking about. Found out that it was the problem, and I adjusted it so I couldn't see any of the threads from the back side. Idle is much smoother than before, and there isn't anymore hesitiation when I try to punch the gas.

My question is, could anyone take a quick look at the screw in the picture I attached, and tell me (to the best of your ability) how far in the screw goes? Does any of the threading show on the back side?

Thanks

 

 

Ethan, right?

I want to be sure what you're referring to. The thread on the back side, without the phillips, towards the side of the intake mainfold, is sticking out 1.5-2mm?

Or are you referring to the other side with the nut?

 

Turn that screw CCW until the tip doesn't touch anything, even with the throttle completely closed.

 

could you do me a favor? I need to know how many theads (if any at all) can you see on the back side of the screw I was referring to (on the TB). I need to know approx. how far out it goes, DBM says it shouldn't come out at all, but my engine feels like it would stall when it was like that.

thanks

 

Back it out all the way. When a technician is adjusting the Throttle Position Sensor he will insert a feeler gauge of a specific thickness between the tip of that screw and the tang on the throttle cable guide. That's the only time this screw performs a useful purpose. If your engine stumbles and stalls when you back out this screw, you have a problem. Perhaps some of that thick coat of gunge is clogging air passages in your TB. You may have to do a more thorough cleaning.

 

This thick layer could be a sign of trouble with your Positive Crankcase Ventilation valve. Please see my recent post Blowby at http://forums.maxima.org/showthread....&postid=466851

 

You have a butt-load of dampening materials !! I have 2 12.1 Perfects in my trunk, and it rattles like a *****. I took off the grey peice and sprayed expanding foam right on the other side of "M A X I M A" and put the grey sheet back. Everything still rattles like mad.

I just don't wanna spend a grand on padding !

Man, you really are an audiophile!

 

well I studided the mechanism of this stop screw. It keeps the throttle cable from releasing all the way, correct?

I had the TB out for a while, and I was pressing the butterfly valve in. Then I tried adjusting the screw since I already messed with it anyway. There's a point where if you don't have the screw sticking out a bit, the idle hole ( a very tiny one at the bottom of the TB right under the butterfly valve) would be covered by the buttetfly valve itself. The more I screw CC, the more exposed that hole becomes.

and I think, if my memory serves me correctly, I remember the back end sticking out a bit. I hope I can get more approximations from everyone.

I totally cleared out the TB, I don't there's a possibility it can get clogged. Thanks for your help though, DMB.

 

I was wondering... if you tighten the throttle cable too much and hit the end... where can i go to tighten the other end...?

 

I hope someone can answer Jung's question. Craig Mack, you're a funny guy. I bought about 3, or 4 rolls of RAAMmat, if you haven't tried it yet, GET IT. raam@raamaudio.com...he has a special price in August. He is probably the best salesperson I've ever met. I was running low on cash and posted a plea on elite car audio, asking if anyone could donate a few strips of ramm mat in an envelope. hehe, pathetic huh? but anyway, he replied, saying that he'd include 4 sq.ft worth in a priority mail envelope. He is a lifesaver, and as whitemax says, a "car audio god." he really knows his stuff, he's a ISCSA (those are the letters, right? heh heh) judge, and he's done probably 3 times the work I've done on my car. anyway, go get some RAAMmat (e-mail me some time too, lets talk)

DBM, thank you for your help. Right now, I feel really great because I took the car out for a drive and everything is feeling a notch better than it was before...acceleration is much smoother, downshifts aren't as laggy, and idle speed is great.

I'll keep an eye out for that stop screw so until then...

 

My reply was reffering to the "other side with the nut" .
I took a look at the side your interested in and it sticks out approx. 1mm and shows no threads, it does not contact anything when the car is off. If you need any more help let me know, BTW Ethan is correct .

 

I agree with Emax. No treads are showing, the end sticks out approx. 1.5mm or 1/16", and it doesn't contact the throttle cable guide. Here's a pic of mine, which hasn't been touched by anyone outside of Oppama, Japan:

 

TarHeelMax, I was dreaming in my head that someone would be nice enough to take a picture of that stop screw I was referring to. THANK YOU!! I can make mine exactly like yours now.

And Ethan, thanks for your clarification, it was great in combination w/ TarHeel's image.

I'm a happy camper again. And my car is feeling faster than ever