I have a 2007 Mustang GT, Manual - BBK CAI, BBK TB, Flows and 93 Bama Tune.
82k miles.

Currently when i start it, it does the normal cold start than idles down to 1000 Rpms little rough but not much. Than hits 750 RPMs and bounces between 500-1000 and sometimes sits at 600 and bounces to 800 than 750 than 1000. Sometimes 700-800 RPMs for a 10 sec than a 750-900 Rpm bounce, You get the idea.

After 3 weeks of pulling my hair out and reading forms I have done the following, I cleaned.....

air filter, Mass Air sensor/filter, Throttle body (highly dirty), Fuel injector cleaner (I know not much help was desperate), and the TPS voltage is at .987Volts

No CEL or codes, no leaks in hoses or unattached and never actually stalls....

I have new spark plugs on the way and I think I am going to buy a new TPS... not sure if thats the issue sense the reading is fine.

Please any advice would help....

Also yes I have looked all over the internet but everyone has seemed to cured there issue after the above. I feel like I have tried everything.

 

It has improved sense but not right still. For some reason it seems to idle at 650ish now and stays between 600-750 really...... But still not right..... Oh and reset the batt a couple times on my adventure here. I did the disconnect reconnect key on not started pump pedal hold down, let up turn off than start for till it warms drive for 25mins thing.

 

Have you unplugged the battery so the adaptive memory clears and let it relearn the idle ? If not do that and then do the idle reset procedure , let it idle for 2 mins with the a/c off and then 2 minutes with the A/c on. I actually let it idle for 5 - 10 minutes for both so it gathers more data.

 

Yup I have done that more than once immidetly after it helps alot than soon after back to surging. I am starting to think the computer is bad I don't know... I have a bama tune that installed correctly and fine unfortantly I don't have the stock cai or tb to swap back to stock

 

Could be a bad bama tune seen this more too often these days

 

My car does the surging after startup. It will stall when the A/C is on. Steeda CAI. BAMA 91 tune. I'm gonna call Bama. Idled fine before.

 

Not that I am defending bama but I know 110% it is not the tune, it did it before. Than I put one in finally to just see if it would fix it plus I wanted the extra power. Honestly just got the car 6 weeks ago and started about two weeks after I bought it. Figures right. Bama tune helped alot on performance I so love it it was night and day hp/tq wise. Honestly I think ill replace the tps with a new one vs just doing the .9v bs. Ill do it with the spark plugs I bought. If anyone has any theories please suggest, ill proably take the car to ford here soon. But I am worried they won't know due to no codes or blame the cai and tb or exhaust. I don't trust dealerships usually.

 

Does anyone know if it could be hurting the car? That's my main concern it never stalls nor is that bad usually on average it's 550ish to 800. I just worrie one day it will blow up or something.

 

Mike I would do what I did. What I did helped a but but it's still funny. Yours is worst than mine for sure mine has never stalled.

 

try the misfire re-learn...I screwed mine up by improper decel first time I drove it after a clear, it would barely run...clear it by unhooking batt for a while, drive till warmed up, get on highway, cruise at 65 or more, at a long offramp let it coast down in gear without braking to under 40...it relearns the crank trigger alignment for misfire detection.

I messed mine up by first time going to work after replacing the battery, lifted on the offramp from pretty fast on a bumpy ramp and pushed the clutch in as I turned off the ramp- the car immediately stalled and only idled with wild surges in rpm...was shocked that it had just learned a bad map, and relearning fixed it right up...Ive got a link somewhere to the official ford instructions on this, but dunno where I put it...but basically ts just warm/over 65/coast down in gear to under 40...during the first coast down it maps the tooth spacing on the crank sensor to measure machining variations, guess it measures minute crankshaft torsional variations to detect misfires by missing/excessive twisting of the crank, measured by time tooth to tooth...hard to believe the computers can read that fast, but they do...

be sure the coast down is on a fairly smooth ramp- think the bumpy ramp likely contributed to mine, as crank endplay and such probably changes stuff as much or more than manufacturing tolerances on the starwheel

 

I didn't start this thread but its helping me. Battery disconnect seems to have worked but I didn't do all the highway and coasting stuff. It was posted after I did the battery disconnect. Thanks for the help. Hope it sticks.

 

Heres a link to the motorcraft pcm section explaining the recalibration... Look at page 14 " profile correction"... Might suggest saving this link, had a hard time finding it again, lots of good stuff in there...

http://www.motorcraftservice.com/vdi...f/OBDSM903.pdf

 

Thanks!!! There are some quality people on here.

 

+1 on the Thanks I saved the PDF instead of the link

 

I have new spark plugs and a motocraft tps ill let everyone know what happens. It was only 150 and the spark plugs were due anyways. But I won't be able to get to it till the weekend or so. Btw mine got worse suddenly. I do think the tps is bad I hope anyways lol. After I do everything I will try that batt reset with the mapping thing. Along with properly doing the resets thanks for the link that helps alot.

 

Btw the only code I get is the p1000 code. I haven't tried to delete it seeing how its just that cycle code. I have driven it at least 200 miles sense I reset the battery I am not sure how long this takes to go away. I've heard it's a tattle tell code for tunes and won't go away. But idk I doubt this has anything to do with the idle.

 

hmm...have heard of a lot of issues with the antiseize fouling the plugs right after a install- was the surging thing there prior to plug change?

 

Well I had time to drop it off to the dealer. They said idk after 100 bucks later lol. Figures, I still need to do the spark plugs and take the throttle body completely off and reassemble. Also the tps I ordered from amazon was broke all well. No worries I just plan to gather my thoughts and start all over again a couple months from now I plan to do a overhaul on the car. Gears, plugs, Tb clean, tps swap, cover up rock chips ect ect. But for now it is what it is and I have to focus on life and catch up and revisit this a couple months when I get time and my buddy gets time as well sense he's a mechanic ill wait for him to look at it when he can.

 

Also no I have not done the plugs yet. Didn't get to it.

 

So I took the evening to completely clean tb all around and put wd-40 on the joints. No diffrence so far. Although feels smoother and not sticky lol idk it sucks all well will do tps I think tomorrow or by the weekend. It is what it is.