I've only owned the car a month, a 2007 GT with 16,000 miles, but the throttle is very unresponsive. The car doesn't decelerate properly when I lift, it just seem to coast with the rpm at a constant level. When trying to rev match on down shift I barely get any response when I blip the throttle between gears. When shifting up the rpms actually increase as I lift off and push in the clutch. Is this normal? It doesn't occur on my other cars.
Welcome to the forum Floyd! we will try to get you fixed up. the easiest things that come to mind are to clean the throttle body (TB) and mass air flow sensor (MAF). there are dedicated cleaners for each. next, I would suggest changing the fuel filter. if the car only has 16k miles, that to me, means the car sat for long periods between startups and drives. run a few cans of your favorite fuel system cleaner thru a few tanks of gas. I use chem-tool B12. you can also change out your plugs as well, read up on that. another obscure cause of "lack of throttle" is the gas pedal itself. these are drive by wire cars so no actual cable from pedal to TB. in some pedals, the circuit that the "fingers" ride over can develop a dead spot therefore the ECM reads no pedal motion until the fingers get to the end of the dead spot. you can search that as well. there is a thread that shows you how to remove the pedal assembly, take the cover off, tweak the fingers, clock the body and put back together. lastly and the most expensive is to get a programmer/tuner with non bama tunes for the 2 or 3 highest octanes in your area, or 2, like 87 for DD and 91 or 93 for having fun. welcome again and good luck
Yea, an 07 with only 16k on it? I'm calling BS. Lol.
But if this is true, then I would highly suggest cleaning the throttle body, maf sensor, change fuel filter,put some top tier 93oct gas in it, then run the balls off of it for a while.....I mean get into it.
Then let us know if the throttle response is any better.
If not, then we'll talk tunes. Btw, Every tuner has had some issues.
Someone fried my cats and it wasn't Bama.
16k miles on an 07 means it was probably driven extremely conservatively, and the adaptive PCM has softened the throttle response.
The easiest way to fix it is to do a few hard runs as suggested by marylandGT, which will cause the PCM to make the response crisper. Just make sure the engine is fully warmed up.
If no luck, then the suggestions from the others should help.
Thanks.
It wasn't a good experience. I know I can be hard to deal with at times. It could have been handled better.
Back on topic. Any updates on your car Floyd?
Is this the first manual Mustang you've owned/driven? When I hopped in a Mustang for the first time I thought mine had a throttle issue as well as it seemed very lazy compared to other cars. I drove another one and saw that it was just as lazy as mine. Now yours could be worse than mine but if not, that is just the nature of these big lazy v8's. When you push harder on the throttle to rev match, does it respond better or no? If it responds better than I don't think you have a problem.
Clean the TB, clean the MAF sensor, disconnect the negative battery terminal for 30 minutes, run through the idle relearn procedure, and then drive the piss out of it.
Of course follow what are "Top-Tier" Members above have suggested.....AND...Since I tend to agree that a '07-MY Stang. that only has 17,000 Miles on it was most likely driven VERY EASY!....Therefore I Myself would also Reset the KAM (Keep Alive Memory) in that "Spanish-Oak" PCM by Removing the Negative Battery Terminal, and keep it off for at least 5 Minutes. Then reconect, Start Car, Let it come up to warm operating temp........Then go Drive it Like You Stole It!:wink: ........
Thanks for the input, I'll try the above and see this weekend. At idle I can floor the accelerator, just a quick blip, with maybe a 200 rpm response from the engine. If I'm at 1K rpm the engine responds. Heel and toe gives virtually no response unless I'm dropping into 2nd and then it seem intermittent.
I ordered a new throttle body motor. The throttle response is never consistent. Sometimes pulling away from a stop I get a big rev and sometimes almost nothing until I press the throttle about 25%. If I let off and depress the clutch between gears the engine rpm goes up 400-500 rpm. We'll see if the new tbm helps when it arrives.
I did all of the above and nothing changed. The only part I have not touched is the pedal assembly. If I can get a response from the throttle when downshifting the revs drop so slowly that the engine is going too fast for the drivetrain. When accelerating, the engine rpm actually increases when the clutch is depressed, as if I don't know how to drive. I've only ever driven manual cars and I'm really old.
I did all of the above and nothing changed. The only part I have not touched is the pedal assembly. If I can get a response from the throttle when downshifting the revs drop so slowly that the engine is going too fast for the drivetrain. When accelerating, the engine rpm actually increases when the clutch is depressed, as if I don't know how to drive. I've only ever driven manual cars and I'm really old.
This much is an emissions control technique that's built in to the ECU. The reason is that on suddenly closed throttle - like during a normal lift-throttle upshift - the engine will produce a brief emissions "spike". Delaying throttle closure and possibly increasing the revs briefly minimizes this. The EPA doesn't care if it pisses off the driver.
I'll do the code scan. The new motor fit just like the old one. There is a spring but there doesn't seem to be a way to pre-load it due to the way the parts go together, and it works (doesn't work) just like the old one. Thanks.
Pikapp had a good question. Was anything modified by the previous owner? Does the air intake tube and filter look stock?
I'm wondering if certain untuned aftermarket cold air intakes would cause hanging and/or fluctuating RPMs. My car had similar symptoms when it was running lean. It would rev higher or hang when I'd push the clutch in while up shifting. Downshifting was the same.
Btw, any update on codes or anything else?
Latest installment. Went out to start the car and it started but the idle was at 600 even though ice cold, and there was no throttle response at all. Drove fine the night before, nothing this morning. I still had the original throttle body motor so I switched them back. The car started normally, shut it off to put tools away, came back and it would not start. Tried 4-5 times and it finally fired and felt normal. I took it for a drive but it surged terribly, 500 rpm over revs on upshifts, I tried a rev match down shift and the engine dropped to the 600 rpm idle and no response to the gas pedal. Switched TBM again, still nothing. I admitted defeat and had the car towed to my shop. They ran all diagnostics and their conclusion is that the powertrain control module believes the throttle to be wide open and closes the throttle and won't accept input from the gas pedal. All sensors and input to the PCM are within spec. Apparently Ford has no parts in-stock, and none are available so my unit is being re-built.
I will be reluctant to say that most pcms on fords side do not fail as often as other manufactures do. I have seen, though, in my work i have done is that when the pinpoint test or the wsm refers to replace any module after series of checking for wiring problems and operation of several items it means something has been over looked. My guess is that the throttle body is not operating correctly, either there is carbon on the butterflies or the motor was not swapped over properly. That spring also does not apply preload to allow the throttle plate to close but to keep it open for idling purposes.
But on the fact that the pcm "thinks" the car is at WOT while the accelerator pedal is showing a CT(closed throttle) application, this will cause the pcm to "shut down" operation to keep from any unwanted acceleration. However, with that said the pcm only gets that information from the output from the throttle body module so for it to believe that i would assume the throttle body is junk.
Regardless how this ends it is in the shops hands to fix it, i hope that when you get your new pcm( in probably 5 months cause thats how long it took me to get one even with dealer privileges) that it fixes your problem and allows you to enjoy your car again. Good luck, keep us posted.
What I was told by the tech was that with the key on everything acted normally, when the engine was started the pcm shut everything down. Hopefully the pcm will fix it, if not, it's on the shop. I asked if putting in a junk yard pcm, just for testing and to confirm their opinion, was a good idea but they didn't think a used part would be reliable. So we sit and wait, 3 weeks for the rebuilt pcm.
The PCM couldn't be re-built (I was told it had death codes) so we had to find a new one from the manufacturer. I hope to get the car back next week. The shop has had the car almost as long as I have
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