Engine problem Supercharged 4.6
 

Car info: 2006 Mustang GT with Saleen blower installed and custom tuned by Performance Autosport (PAS) in Richmond, VA. Driven it for almost 2 years now without any problems before the one described below.

A couple of weeks ago, the battery short cut when turning the ignition nothing happened except that I heard some "ticking" sound from the dash board. Replaced the battery and everything seemed fine.

Now 2 weeks later with the PAS tune loaded, the idling rpm is unstable 800-1300 rpm and changing with the on/off of the AC. When pushing the accelerator pedal in first gear (even only slightly), the engine revs uncontrollable and I have to turn off the ignition to get it to stop. Have reset the onboard computer several times according to the manual and let it run and adjust idling rpm according to every instruction available, but no improvement.

With the Saleen tune loaded (the one Saleen re-flashing the onboard computer with when it was sent back to them when the blower was installed), the idling rpm is stable at approx 750 rpm, but when driving 60-70 mph on flat surface, you can feel acceleration/deacceleration once every second, pretty much like the accelerator pedal was pushed slightly every second. Similar behavior also with the cruse control on. When shifting gears and pressing the clutch down, the engine revs 200-300 rpm before returning towards idling rpms. Also, the engine feels a little bit lame, like it has lost about 100 hp.

Started with changing the throttle position sensor - no improvement. Changed the entire throttle body (replaced the Ford stock, with a brand new Ford stock), but this did not solve the problem either.

No "engine failure" light is lit and no error codes in the onboard computer.

Anyone experienced similar problems or have any suggestions how to get this problem solved?

RE: Engine problem Supercharged 4.6
 

I had this problem with my paxton, but to add to your story when comming up to a red light the car would stall out. The steps i took were moving my heatshield lower on my intake, cleaned my TB and Sensor and reset the computer. This has fixed my problem with the idle. Im not sure about the ticking, only thing i can think of is the starter maybe. Im sure someone with more tech then i will chime in and help you further. Goodluck.

RE: Engine problem Supercharged 4.6
 

You've driven the car for two years, and are only now noticing some of this?

The idle change with AC is SOP. My car has done it the whole way through. The AC compressor puts more strain on the serpentine belt, as does the blower, so the idle "stumbles" a bit while it attempts to catch up.

The revving a couple hundred R's before falling down.. This is by Ford, by design. Every manual transmission Mustang out there does it. Something about burning off excess fuel or some crap. I forget the actual reason, but it, also, is SOP.

I'm sorry I can't offer any advice on the rest of your problems.. :-( Well, maybe.. Have you cleaned the MAF lately?

RE: Engine problem Supercharged 4.6
 

So why is one tune working and one isn't working anymore? Why is only one tune having idling problem recently while it has worked fine for 2 years before that? Wasn't really any useful answer you came up with, was it?

Please, I do not really need any wise guys to tell me what is SOP and not, I need suggestions how to solve the problem that has occured now.

The problem isn't really the uncontrolledidling , it is the immediate uncontrolled reving of the engine, and thus acceleration out of control, when driving. Would be really nice to be able to use the old PAS tune again.

RE: Engine problem Supercharged 4.6
 

Clean the MAF first and then come back with new results......this seems like it could easily be a part of the problem

RE: Engine problem Supercharged 4.6
 

Listen here, Newbie. You came in here looking for information. I'm simply telling you that two of the "symptoms" you describe are THE WAY THE CAR IS SUPPOSED TO BEHAVE, meaning that you needn't worry about them.

If you want to be a dick, that's your prerogative, but I doubt you'll get much help from anyone if you continue.


BTW - welcome to my ignore list.

RE: Engine problem Supercharged 4.6
 

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RE: Engine problem Supercharged 4.6
 

did you have to extend any of the sensor wires for the saleen install? Sounds like a wiring problem. You could have a pedal position sensor that's going bad, but i've not heard of that happening to anyone.

Obviously a vacuum leak would cause the surging while at idle and cruise, so definately check all your vacuum hoses.

RE: Engine problem Supercharged 4.6
 

+1 to vacuum leak or a dirty MAF sensor

RE: Engine problem Supercharged 4.6
 

Maybe your the problem exx. I have seen you not get along with alot of people and you saying your on my ignore list numerous times. Think about it?:eek: