High Revving Engine

[nsstang]

Just wondering if anyone out there is having an issue with their car not idling down when coming to a stop. Different times it's continues to rev around 2000 - 2300. Giving it a quick shot does not help. Any ideas what causes this?

[fcettner]

Sounds like a tuning issue. I would re-flash the tune and if that doesn't work datalog and send file to your tuner so he can see the trims.

[2007tungstenGT500]

this seems to be pretty common from my experience, both with the FRPP tune and now my current Jon Lund tune, but at more like 1,200 RPMs (until completely stopped). it used to happen at a higher RPM on my 2006 Mustang GT, like you are describing, but it resolved itself when i switched from a canned DiabloSport tune to the FRPP tune. hope that helps.

Edited July 31, 2014 by 2007tungstenGT500

[2010KonaBlueGT]

Sticky throttle plate? Loose blade?

 

I've seen this happen when one of the blades gets a little loose. They'll shift and give you a intermittent condition.

 

Or the shaft will gum up.

 

Or the throat will get a build up of gummy shit from the fuel fumes that accumulate.

 

I recommend you clean your throttle blades, shafts and throttle body throat/s with a shop rag and some berryman/chemtool carb clener. I do it every so often on ALL EFI cars. Can't tell you how many customers have gone off happy as hell for very little money (it's a common problem with EFI cars).

 

I always tell people to START WITH THE BASICS. Don't just automatically jump to the conclusion that it's a bad tune, or PCM problem or something of that nature just because it is computer controlled. It can very easily be something real simple like gummy TB, vacuuum line off or split, etc. etc. etc.

 

I mean, if a car is overheating wouldn't you check the coolant content/level FIRST? Or would you automatically jump to the conclusion that it's a stuck t-stat, bad coolant sensor, etc.?

 

Basics my friends, BASICS.

 

 

 

Phill

[CSX4833]

I've had this problem since day one but only at certain times. Sometimes, it'll idle as high as 1800 for quite a while. I was told by SA that this was normal depending on the conditions. It doesn't happen often, but goes away after I pull away. I have found that it does it less if I let the engine slow down with it in gear (as opposed to coasting in neutral).

[nsstang]

Thanks all. Will try a little cleaning. Thought that things may be getting a little gummed up.

[2007tungstenGT500]

you should also buy some Mass Air-Flow Sensor Cleaner, while you're at it. you don't need to use much...just a couple sprays and let it dry. over-oiling your air-filter can also wreak havoc on the sensor, in turn causing strange behavior. not saying that's what you've done, but any kind of debris can cause issues with the sensor.

Edited August 1, 2014 by 2007tungstenGT500

[nsstang]

So the Mass Air-Flow Sensor Cleaner does work? Just spray and leave it? No wiping or cleaning needed?

[2007tungstenGT500]

that is correct.

[nsstang]

Thank you. Will try it first thing in the spring.

[NJPat]

OP-

 

WHAT THROTTLE BODY DO YOU HAVE?

 

THE FRPP OVAL TB CAN SOMETIMES STICK, AND THAT WOULD RESULT IN THE CONDITION YOU DESCRIBE

 

IT HAPPENED TO ME A LOT, AND HAD ZERO TO DO WITH THE TUNE (WHICH WAS JON LUND)

 

JON LUND WAS THE PERSON WHO DIAGNOSED THE PROBLEM, AND NOW THAT IT'S FIXED IT'S A JOY TO DRIVE

 

BEST

 

PAT