Digital Tuning 2005 Mustang Gt Idle Problem

Discussion in '2005 - 2009 Specific Tech' started by Harpreet, Jul 13, 2013.


  1. Harpreet

    Harpreet New Member

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    Hey guys I've recently been having some problems with the idling on my 2005 Mustang GT. So the other day I was gone for a drive on the highway and my cruise control randomly stopped working and later that day at the lights my car tried stalling so I revved it up high and the attempt to stall and the rough idle went away. The next day after I started it up it again didn't seem to be idling right but wasn't that bad. So I decided to clean the throttle body. After cleaning it, it now seems to be way worse. It idles around 2000 rpm and when I rev up it comes down really slow, also sometimes it randomly drops down to 1500 or shuts off. So I think it may be the TPS. Even when I turn the car off I feel an odd shake that is not suppose to be there from the front of the car. The engine light has been on since I got long tube headers and high flow cats a couple months ago, because of the O2s. But now it is giving some more error codes. I have reset the computer and erased the codes a couple times and I've gotten a bunch of different codes every time I reset it. The codes that it has been giving are (P0122, P0223, P061b, P2106 and P2110)(P0507 and P100)(P0122, P0233, P0507, P061b, P1000 and P2104)(P1000). Any idea what it could be? I'd like to know if it could actually be the TPS before I go out and replace it. Also do you think the car is drivable to my mechanic? Please let me know if you require any more info. Thanks
     
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  2. 805mustang

    805mustang Member

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    How did you clean the throttle body...more importantly how did u open the throttle plates? Did you just force them open? Was the key on or off? It sounds like you need to reprogram your PCM. Do you have a tuner and is your car tuned for the mods you have? After clearing the codes do any come back with just cycling the key off and back on.....not actually starting and running the car? Lets start with these questions and I will be able to give you some advice.
     
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  3. skypig

    skypig New Member

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    I evidently have done the same thing on my '06. I cleaned twice - first time forced open with key off, got check engine lights that cleared themselves. Second time I had someone sit with key on and held accel to floor. I get much better throttle response/control at low RPM, but returning to idle is fairly slow. My car is straight stock. I there anything I can do to get the car back to idle more quickly? In addition, is there a good scan tool out there for mild performance boost/read out check eng lights?
     
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  4. Harpreet

    Harpreet New Member

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    I took the throttle body off of the car and then cleaned it by manually pushing open the throttle plates. the key was off when i took off the throttle body. I do have a hypertech tuner but it does not allow me to tune for all my mods. I have jba long tube headers with a catted H-pipe and a roush intake, my tuner only allows me to tune for the intake. i cleared all the codes and turned the key to the on position and p1000 was the only code that came back up.
     
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  5. Steve491

    Steve491 Member

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    These are electronically controlled throttle bodies and CANNOT be pushed open with your finger. At best it can be recalibrated to the ECM, most likely you will need a new one. I learned this the hard way with a Nissan I used to have. Idle is not only controlled with the AIC Solenoid, but the throttle body itself. Imagine the computer adjusting it's foot on the gas pedal multiple times/second keeping the idle at 700 rpm? That throttle body has to be very accurate. Like I said, I learned the hard way with my wife's old Altima.
     
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  6. skypig

    skypig New Member

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    I hope I didn't screw the pooch but took off throttle body and cleaned it, once again manually pushing open to get everything. I disconnected battery while I was cleaning, reinstalled and idle is fine. Doesn't fall too quickly when I shift, but high idle seems to be cured. Drove a few manuals looking at these and don't remember how quickly they dropped rpm during shifts - it may be considered normal. I would still like to hear views on a tuner that would do me some good with stock parts that also reads codes.
     
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  7. 805mustang

    805mustang Member

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    I also say that you should not open the throttle body by pushing it open, rather turn the key and have a friend press the pedal down or use a broom stick or something similar and wedge it between your seat and the pedal, or if u have a scan tool use that to command it open. With that said I also took my throttle body off and did the same as you and it was fine, no codes no idle issues. When I worked in a shop cleaning throttle bodies was a pretty regular thing.....I was never told not to push the throttle blades open on electronic throttle bodies, we probably did a dozen cars that way until my boss did one on an infinity and sure enough the car would not idle correct after. The car was sent to the dealer and reprogrammed, it did not need a new throttle body! I have heard sct tuners are good and can tune for specific upgrades......they can be updated for free for life and you can download specific tunes for nearly every upgrade with a pc. I would look into one of those. Does your tuner have the capability to view live data? I believe the tps sensor should be between .7 and .9 volts at idle. You can use a multimeter if your tuner won't work. It sounds like you need a proper tune to fix your issues. If your still getting throttle body codes you may need to have your PCM reprogrammed by the dealer as well. Have you tried to disconnect your battery for (20min) then re-tune your PCM? What codes do you get then? What codes keep coming back?
     
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  8. 805mustang

    805mustang Member

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    I went ahead and looked up all your codes from the previous post and all but 1 relate to the throttle position and throttle actuator sensors. Both of which are located on either side of the throttle body. If the codes keep coming back I would recommend a proper tune and a reprogramming of your PCM (dealer only)
     
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  9. skypig

    skypig New Member

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    I did not have codes - but could not leave well enough alone. Idle getting a little better but still a little high. I cleaned MAF, and thought I would pull TPS/actuator to see if any play on shaft or debris etc.....stinking TPS bolt sheared right off. Only the bottom one good now. I doubt an easy out will get top one out. Can it be drilled/tapped? Should easy out be tried first? Lastly is a new body in order? If so is a bigger aftermarket a good idea - going to keep rest stock for now.
     
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  10. 805mustang

    805mustang Member

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    Stock throttle body is just fine.....capable of much higher air flow than what stock or modded engine uses. I would try easy out first.....get some penetrating oil on it and let it soak for a little bit. They are tough to get out .....I thought I was going to break one too. If there's anything showing try vice grips, with either easy out or vice grips try turning both ways until it losens up, then back it out! Last resort ......DRILL IT!!! I have had to drill and tap smaller bolts/screws before, just make sure your straight. I would do it out of the car for obvious reasons! Might even leave sensor in to use the hole as a guide!
     
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  11. skypig

    skypig New Member

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    Ok thanks - give it a try. I have changed throttle body parts before on other vehicles with no problem at all! Once I get past the broken screw I would still like to see a quicker rpm drop during shifts and a slightly lower idle. I did see mention of adaptive learning (idle and auto trans shift) in manual but I have driven it 150+ mi since replacing body and idle still takes awhile to retard. Most noticable when I am downshifting. Before I cleaned, got a nice braking action in 2nd with a throaty tone - now acts like it holds idle >1000 rpm during decel, no roar until almost stopped. I stop - then will settle to around 700. May be normal, but would like more snappy reduction. Any ideas? Called 2 ford dealers, one said make appt we can flash, the other said no need unless he sees a reason.
     
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  12. 805mustang

    805mustang Member

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    I would compair to mine but I have a 5speed......and I love to engine brake! It take a few seconds for my car to drop below a 1000 as well when I come to a stop. It likes to sit right at a 1000rpm then will drop to 740-750! Have you tried unplugging the tp sensor and snap the throttle???? Any difference? Adaptive learning means if u drive like a grandma it will respond like one, if you drive like Kyle Busch it will respond like a race car....more so with your shift points if you have an automatic! I'm not saying drive it hard but you don't want to just cruz all the time.....RIP INTO IT BROTHA! When it's warm, after a drive......if you snap the throttle in idle/park will it drop to 740ish or will it hover around a g then fall to low 7's
     
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  13. skypig

    skypig New Member

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    I have a 5 speed as well and I don't leave any hp unused! The idle response now sounds much like yours, but before I cleaned it snapped right back to around 650 without the 1000 hang (engine braking was much better then). Does your rpm hang up high during shifts if rpm > 3000 ish? If I do drive more gently(shift around 2500 or less) the rpm does drop ok, but as soon as I get in just a little there is a good delay in rpm decrease such that when I hit the next higher gear the rpm has to drop a good bit to be locked in. I was worried about clutch wear. Maybe this is normal ops for this rig, just doesn't act like my old manuals ('66 stangs, '73 vette) did. It is as if I don't get my foot off accel enough when in fact I take it all the way off.
     
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  14. 805mustang

    805mustang Member

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    That is how my car runs as well......a couple things to remember, the higher your rpm the more rotating force you will have at your fly wheel so it won't suddenly drop to idle! Also these are electronic tb's so the throttle will not snap shut as in an older car....it's safer on the engine this way. Rapid deceleration can be very bad on your motor! My car is acting up right now and does seem to idle slightly high according to the data.....not much though. It says warm idle should be about 700 and I'm at 750! I have a problem though.....not positive what but I'm suspecting a cam phaser solenoid! I have a decent scan tool and can monitor throttle position and rpm! I notice that I get a rough running condition between 1200 and 2700rpm so it's hard to compair the two cars! Also I have noticed my scantool will sometimes say pt (part throttle when it's actually suppose to be ct (closed throttle). I have no engine light on or any misfire data so its not an easy diagnosis. Are you getting any codes back? Did you do anything but clean throttle body recently, anything at all? Does the car seem different to you in regards to falling rpm's? How long have you owned this car.....are you quite familiar with it? Did you stop driving it for a few days and start driving a different car.....vette or classic stang? I know that tuning your car has a lot to do with changing the throttle response.....tricks you to think you gained hp and torque. If you want we can compare .....wait until your car is warm and had been driven then let it idle for a few minutes then hit the throttle to 3 or 4 grand and time it or take a video.... I can do the same if you want!
    P.s. good to hear you have a 5 speed and driving it like a champ!
     
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  15. skypig

    skypig New Member

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    No rough running, no codes, and sounds very similar to your ride. Other things I did were disconnect battery for 30 min to clear initial check eng light, sucked a can of Seafoam thru brake boost vacuum line, and replaced stock air filter with a K&N that fits in stock hole. I still would expect a little sharper drop during shift just to get it close to next expected rpm even considering the extra flywheel pop, but sounds like that is the way Ford planned it. My idle is now right at 700 if I let it sit for a few seconds after a complete stop. I did not used to have to stop - idle just moved smartly back. I suspect that I have the same pt vs ct issue now after cleaning - have a Dodge that is programmed to hang up in the decel around 1000 using IAC in a similar manner. Dodge mechanic buddy told me that was a design thing for reduced emissions in decel (BS?) I only base my ford pt/ct on less effective engine braking initally and what I can see on MPG indicator in dash. If I do a prolonged engine brake in 2nd it will eventually act as it did before (suspect it finally gets ct with increased eng braking and throaty growl)Regardless, I think I will leave it alone for now - thinking of doing mods thru Anderson Ford Clinton IL - they have a performance shop associated with the dealer. If I understood correctly they use an intake, throttle body, MAF, headers, and a diablo tuner - maybe injectors?? as a kit - just north of 2 grand with a dyno I think. Still haven't got the TPS screw out - had already done what you suggested except easy out/drill. Will try tomorrow - if works I will sit back and let dust settle awhile, think about mods if it doesn't.
     
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  16. 805mustang

    805mustang Member

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    Your idle is perfect at 700, are you basing that number on the original tach in the car?....do you have a scantool that can view live data? I know you said you had headers right? What about mufflers.....stock or aftermarket? if you put your ear up to each muffler do they sound the same? Have you cleaned your air filter with a recharge kit? Or changed your oil recently? is your pcv system still hooked up or do u have breathers? When you engine brake and it makes the same noise as before is that only because your playing with the clutch or are you setting the ebrake and throttling it too? When you say it doesn't sound as throaty is that only at idle or when decelerating ....say around 2 grand in second gear? that's when it really roars? Does tuning it make any difference in this rpm issue ...tune vs non tuned? Last question....you say rpm don't drop fast enough when shifting, do they kick up ever so slightly then drop?.......they really should not drop much when shifting under any acceleration? Answer these last questions and I will have all the info I need to tell you what you need to do to diagnose this issue! There are only a few reasons rpm will hang up and exhaust and or intake rumble ( throatiness) would occur! Air fuel ratio is off, throttle body is not closing fast enough or closing all ( most likley this way due to sensor being slightly off or valve timing is slightly off or not retarding enough. In your case I'm almost sure it's has to do with the maf or complete throttle, with both tb sensor
     
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  17. 805mustang

    805mustang Member

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    Just answer these last questions and I can look up in my scan tool for possible causes and related tsb's! And when I said a/f ratio many things will cause this, maf, map, airtemp, baro sensors, all in the same sensor...mass air flow sensor ......is also the baro, air temp,map, Throttle sensor will also have this effect, more noticeable issues would be an issue with your slow idle return would be a cam timing, compression issue. Without the last few questions I can only give an educated guess! Right now I will say it sounds like a throttle body/tp/small vacuum leak or var-valve-timing phaser/phaser solenoid! Please answere these questions as I would like to know if there pertain to my whip! I will do a little research ! Make absolutely sure at idle between 1100-2300 in neutral you have no rough conditions, there minor but you'll notice. If it does I know your problem, if not I also have an idea! -thanks ---mike
     
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  18. 805mustang

    805mustang Member

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    Oh and iac can reduce emissions if set right!
     
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  19. skypig

    skypig New Member

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    Based on car tach - no scan tool, no headers, all stock except brand new K&N for stock breather. Oil change yes, but well before these symptoms. Eng brake with my foot completely off accel - as I said noise and performance different than before clean - seems like throttle does not close all they way until rpm gets below about 2000 - that is when it starts to sound like eng braking. RPM does kick up slightly on high rpm shifts, not on shifts below around 2300.
     
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  20. skypig

    skypig New Member

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    Have to revise info - just drove and the rpm kick up can happen at any rpm, but more prevalent today in the 2000-3000 band. Early in the drive today the rpm dropped well from 3500-4000 during shifts. but as car got warmer the rpm kick up thing even got up in that range sometimes
     
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