OK...

Long story short, I'll keep it nice and simple. Did TB mod, intake porting, etc, car didnt want to start, it was massively flooded... Got it started, had to keep my foot on the throttle while it blew white smoke, then it finally idled on its own but at 500.

Did everything on RETed's site for adjusting idle, everything in the FSM, still idled at 500-550. Also cleaned the bac and checked its functioning (seems to be functioning when 12v power and ground are hooked straight up to it but not when it's plugged in).

Started it again today after sitting over night and it started but then stalled imediately. Had to put my foot on the throttle for about 5 min or so then it idled on its own, once again at 500. Only way i was able to get the idle up (after checking and adjusting everything in the FSM AGAIN!!) was to tighten the throttle cable. It seems to idle fine now and start every time, but I dont know what will happen tomorrow after it's been sitting.

Any suggestions or ideas why it's doing this?

 

bump

 

Tightening the throttle cable has probably done the same thing as playing with the throttle stop screw. You've just opened the primary throttle a bit. You should loosen the cable to the specified slack, and then use the throttle stop screw to get it to idle.

It sounds like the BAC valve isn't working. With the ignition on and the engine not running, you should be able to hear the BAC valve buzzing as it's rapidly pulsed open and closed by the ECU. If it's not, but it does click when you put power and ground to its terminals, then it may be an ECU problem. Read this page for more info on checking the ECU's BAC valve circuit.

 

What's the throttle stop screw exactly?

I did everything in the FSM to adjust the idle but none of it did anything. The screw on top of the TB is as open as it can be, the variable resistor was messed with, the TPS is set to the specified 1k and is functioning properly, and it was idling at 500-550 at most. The only way i could get it to idle properly was tighten the throttle cable thus opening the throttle slightly. I realized this is kind of cheating, but I didn't know what else to do.

 

If you look closely at the primary throttle linkage, you'll see a screw that can be used to adjust at what position the primary throttle stops at. It's on the side facing the firewall, and it's on top of the TB on turbos so it must be on the bottom on NA's.

 

Bottom of the TB? Like under the dynamic chamber? I'm confused... Isn't the throttle linkage what the throttle cable hooks onto thats located on the firewall side of the TB?

 

It is indeed on the bottom on a non-turbo. But you can overcome this. If you look at the front of the throttle body there is yet another throttle stop screw. Its for the secondary throttle plates. Apply your screwdriver and 8mm socket to that one and give it a go.

Or......just remove the throttle body. Its just four 12mm socket size nuts and a water hose and a little of this and a little of that. Off in fifteen minutes.

 

Yah I'll have to remove it then since I did the TB mod and have no secondary plates anymore

 

Yes you do. You've removed the #2 secondary plates. If you removed the other set, which sit directly above the primary plate, you'd have an unthrottled engine...

 

Yes I know.

Hopefully playing with that will fix my idle, cuz I've seriously tried everything in the idle setting/adjustment how-to's and what the FSM says like 10 times

 

will the TB mod lower the chances of passing smog?

 

Not that I have read or know of.

 

May this will help..



Yes- I know the TPS lock nut is loose.
I was adjusting my TPS when I took the picture.

Note: You still may have a BAC problem, and you will need to reset the TPS after changing the idle stop.

 

Playing with that screw did absolutely jack ****... Still idles at 500


Anyone know WHY my car is idling so low?

 

BAC valve!

 

Hmmm, but people block off the BAC valve all the time, so why is it being such a bitch for me and my idling?

 

Also, my BAC valve wasn't working before I did the TB mod/porting/etc etc etc, so why would my idle have dropped so much after doing all this?

 

The BAC valve isn't working, thats probably your problem then.

BTW- NZ, that link you posted doesn't work, any other links to info on the BAC valve?

 

Yah i understand my BAC valve is probably not getting the signal from the ECU or something... but my question is, how come its making a difference now? Before I did everything my idle was perfectly fine (actually a tiny bit high) but now all of a sudden it makes a difference, why?

 

it's just idling low right? It's not like it's erratic or anything? You could adjust your timing some, or check the resistence on the TPS. If it's erratic i'd say you have a vacuum leek.

 

it's not erratic, the TPS has already been set... My problem is that it idles way too low, so if i start it when its been sitting for a long time it dies at first because it doesnt like idling at 490-500, so i just have to hold the throttle down for a couple min then it idles on its own, and if i turn it off/back on it will idle on its own right away (meaning when i start it when its warm). So i also dont think its a vac leak since it's just low...

What do you mean by adjust the timing? I've checked it when my idle was 750 and it was right on where it should be... are you talking about either advancing or retarding the timing?

 

Bad link, sorry about that.

http://www.teamfc3s.org/info/articles/idle.html

You need to find the throttle stop screw that governs how far open the primary throttle sits with your foot off the pedal. The screw indicated on the picture above is not it (it's on the secondary shaft). When you turn it inwards you can actually see it opening the primary throttle. It's a foolproof method. If it doesn't work you either have the wrong screw or you have a vac leak somewhere.

You've just done the TB mod and had the manifolds off, so check for vac leaks at the TB's plugged holes, vac lines, manifold gaskets, etc.

 

Yah I took everything off again today and found that one of my silicone vac lines BROKE somehow...

So I replaced that and left everything off cuz I'm getting the replacement solenoids tomorrow and after replacing those I'll see how it goes

 

I find it more than just a littel bit odd that you say you adjusted that idle stop screw shown in the picture and got no response with the idle. That screw will crack the secondary throttle plates open if you screw it down/clockwise. The one with the 8mm size jamnut is the one I am talking about.

Fixing a broken BAC is in this article for turboii cars. It's down at the bottom quarter of this link http://www.teamfc3s.org/info/articles/idle.html

People who remove the bac, for whatever strange reason, usually have to adjust the THROTTLE STOP SCREW to get the idle up.

 

I have no secondary throttle plates, i did the TB mod