mojopony

My '06GT was idling rough so I removed the throttle body and cleaned it with CRC cleaner. After re-installing the T/B the idle is now smooth & steady, but every time I fire up the car the RPM's jump up to 2,000 and then it settles back down to a normal idle. The rev's have always increased a bit at startup, but never this much. Any advice or input would be greatly appreciated.

ticopowell

Did you reset the computer when you cleaned the T/B? unhook the battery for a few minutes and turn the lights on to make sure all the power is drained from the system, then hook it back up and see what it does.

waykooljr

You should go through the idle relearning process anytime you disconnect the battery, you could even try disconnecting the battery for a bit to try this to see if it helps with your problem.

The process is in your owners manual, on page 204.

Here's a link to the owners manual from Ford, 2006 Ford Mustang Owner's Manuals

mojopony

Thanks guys. I did disconnect the battery overnight, but I didn't follow the re-learning process as specified in the manual. I'll give that a try. Thanks again!

drewsky

The first time I cleaned mine years ago it did this. I started the car and something wasn't right, shut it off immediately and realized I didn't plug the left (driver side) wire harness back!! It revved up just like that for 4-5 days on startup then settled back to normal.. If you disconnect the battery for a while it should solve it right away.. If not don't freak out. It will return to normal, could also be it was really dirty and the computer is adjusting to clean easy opening tb. Just a thought

mojopony

I tried disconnecting the battery again and went through the idle re-learning process per the manual. No change at start-up. I checked the TPS voltage and measured 1.24 volts on my meter. I'm guessing that's around nominal, but I'm not really sure. The culprit must be some quirky thing. I'm not gonna sweat it too much since its not a major issue.

Nuke

Check for air in-leakage before going nutz.

dlazrael

How exactly do ya check that?

Simon1

Ever since mine has been tuned it does this. With the first tune it was higher.

Nuke

Check all of the plumbing ahead of the TB. Any clamp or joint could have slipped or loosened, allowing a gap which allows unmetered air into the engine. There's also occasions where people over-tightened a clamp, deforming the connection.