unusual idle/click click - vid inside

[JPstealth]

Hey all... had this 00 GT with 64k miles for about a year now been. I have been at school and dont drive it much.... i cant seem to get any straight answers out of anyone so ill try my luck here...

car has a wierd idle.. drops to about 600 or so bubble a bit then shoots up to 1k.. when rpms drop it makes a click click noise but seems to disappear as rpms climb. SES light is on saying running to lean as well but i think that just may be to the mods. Ford tells me the engine is built and may have cams but I dont trust them.

engine mods from what I can tell:
C&L intake and MAF
K&N filter
reichard Racing manifold
LT headers of some sort
3inch Hpipe w/cats
3inch catback

Remedies to try to turn off SES light:
new MAF
cleaned k&N and whole intake
New IAC
cleaned injectors
new fuel filter
checked for vacuum leaks


thanks


any ideas???

VIDEO....

YouTube - 00 mustang GT idle

 

[JPstealth]

oh AND it has some weird bolts that obviously look like that have been put there any ideas to what they were for??

 

[snidehockey]

well the only thing I really see there that hasn't been done is your front o2 sensors. Also maybe you're injectors are gunked up.

as for those bolts...they're studs of some sort for something that was previously mounted (obviously) not real sure what would go over there though...

 

[RedDaemon]

i would try changing out your IAC (Idle Air Control) to see if oyu can get the rpms to even out at idle. or at least try cleaning it ($45 at NAPA)

you could also try putting some of your favorite fuel system cleaner in your gas tank

 

[Killa]

if you ever need to buy a IAC, get one from ford !!!!

 

[blubullett]

Those bolts were for a strut tower brace.

 

[JPstealth]

did both.... have a new IAC and cleaned the fuel system...multiple times

strut tower brace? well i wish they left it on in that case

 

[RedDaemon]

if you ever need to buy a IAC, get one from ford !!!!

the one i pick up from napa is the same thing. the only difference is that the serial number engraved into the aluminum is not there. ive been running a NAPA IAC for about 2.5 years now. works just fine


i understand where you are coming from, however.

 

[nyuk98gt]

JPstealth:

Have you pulled the codes to see why the light is on? There are many, many causes and you don't want to throw parts at it (unless you are wealthy and handy with a wrench and have the time). You can get them read at AutoZone or you can use an XCal or Predator (if you have one). Once you know what the root cause is, it is easy to fix.

If the engine has cams then the problem might be in the tune. Look at the PCM (passenger side footwell) and see if there is a chip installed. If not, the PCM may have been reflashed by the last owner. Do you have contact info for the original owner? If so, you can find out what is in the engine and if there is a custom tune.

HTH,

Chris

 

[Smokeurhonda]

Could also be a vac leak.

 

[AdRock]

It doesn't sound at all like it has aftermarket cams. With the way the idle hangs then drops I'd bet there's a vacuum leak somewhere.

Do you have any aftermarket tune in the car? I

s the C&L MAF larger than the stock MAF?
If it is and you don't have the ECM tuned for it it could cause these problems.

Your IAC is working because it's trying to get the engine to sit at the idle it's supposed to.

Try starting the car and while it's hunting for idle, just unplug the IAC and see what happens. With the IAC unplugged the car should either die or the idle will settle either high or low but quit hunting. Then check for vacuum leaks with it unplugged. If you leave the IAC plugged in while you check for vacuum leaks (by spraying carb cleaner around all hoses and gaskets) it can sometimes give a false rpm jump or drop. If the idle will stay stable, whether it be high or low, it will allow you to notice and activity when the cleaner is being sprayed.

 

[fastfive_ogt]

Is the lean code just one bank or both banks? Meaning p0171 and p0174? If your get both banks lean you 9 out of 10 have a vacuum leak. Unless the maf is bigger and then the pcm can't tell that so your voltage at the pcm from the maf is to high at idle which means its seeing to much air or at least it thinks that. You will have to get a flash for the maf then. But its pretty simple if thats not the problem. You can take it to some one who has a scanner like ids or snap-on maybe and get them to read the fuel trims long and short. If you get that there is a tsb to figure out whether its a vacuum leak or not. I would have to look it up but I believe its adding the long and short trims together and divide by 2 or something. I can look it up for you if need be. But these are all things you can do. Unfortunately you can't do much diag work anymore with out haveing a scan tool or for that matter having an IDS for fords. I am a cert. ford tech. If you have any more ?'s just post them I will check back. Hope this helps. Good luck.

 

[Badd GT]

my wifes car has the P0174 code. i thought it was the O2 sensor........i changed it and it seems to run worse.

anything else?

 

[the98stang]

Could also be a vac leak.

+1

vac leaks will cause high idle..i would start there

 

[R.J.]

Now that you have replaced your IAC, try resetting your idle with this procedure.

1. Disconnect the negative terminal to your battery and turn on your headlights for about 10 minutes(there's a lot of speculation as to how long. some people will even say to disconnect the positive terminal and some people will say to leave it disconnected over night.)

2. Disconnect the wiring harness connector to the IAC

3. Turn off headlights and reconnect battery. DO NOT TOUCH THE GAS PEDAL!!

4. DO NOT TOUCH THE GAS PEDAL!! Try to start the car. If the car won't start adjust the set screw on the throttle body a 1/4 - 1/2 turn and try again. Repeat until the car will stay running. It will run rough but that is what you want.

5. Let the car sit and idle (DO NOT TOUCH THE GAS PEDAL!!!) until the car reaches operating temperature.

6. DO NOT TOUCH THE GAS PEDAL!!! Step 5 allows the computer to relearn idle settings. It's pretty cool when you follow my procedure because you can actually hear and feel the car figuring out the proper idle settings. It will go from idling rough to idling smooth as it warms up. Once the car is warmed up verify that the car is idling at around 700rpm. If the car is not idling where you want it, adjust the screw until it hits ~700rpm and then let is sit maybe another 10 minutes DO NOT TOUCH THE GAS PEDAL!!!

DO NOT TOUCH THE GAS PEDAL!!!

Turn the car off. Reattach IAC wiring harness. Now remember we adjusted the set screw on the throttle body. That means that the voltage reading from the TPS sensor has changed. It should read between .96 and .99 volts. Anything outside of that range will cause all sorts of issues including misfires and rough idle.

7. You will have to back probe the TPS connector. With the connector attached to the TPS stick a paper clip into the rubber boot on the connector where the top and middle wires go into the connector. The rubber is very flexible the paper clip will slide in between the rubber and the wire.

8. Set your multimeter to volts. Turn ignition to ON. Then place your multimeter leads on the metal pins. If it comes up as a negative that is okay as long as you are -.96 to -.99. If you get this reading then great you are done and hopefully your issues are gone. If not proceed to step 9

9. This is where and extra pair of hands come in handy. Using a large screw driver you will need to loosen the bolts that hold the TPS. DO NOT USE A SCREWDRIVER THAT IS TOO SMALL BECAUSE YOU WILL STRIP THE BOLTS. They probably will be really tight so you have to really lean on the screwdriver and use some finesse.

10. Once the bolts are loose you will need to move the TPS up or down and continue to read the voltage. Once you get it to the desired setting you can retighten the bolts. What I do is I find .97 and then as carefully as possible I tighten the TPS down. what will happen is the voltage will change usually to .96 or .98 but that it okay. Once you are done with this manually open the throttle body a few times and close it then reread the voltage and make sure it is still within our desired range.

11. Depending upon how loose your set screw was you might want to cover it in RTV to hold your setting. At this point you have CORRECTLY reset you idle.