Minor hanging RPMs

Discussion in 'SN95 4.6L Mustang Tech' started by Jinx, Apr 13, 2012.

  1. 2003 GT
    108k on the clock

    RPMs seem to hang at initial start-up and when coming to a complete stop. They eventually drop to normal idle RPMs and there is no stumble or rough idle. I think it may be a sticking valve, because fuel consumption has not increased and power levels seem fine.

    everything air related between the TB and exhaust manifold is original 2003 stock.

    I've listened for vac leaks, and can't seem to hear any.

    Any other suggestions before I take the IAC off for cleaning/replacement?? Is there a how-to write up somewhere??

  2. Replace IAC = win

    It's not rocket science... remove 2 bolts and the tubing running to the IAC and replace.
  3. Yeah, been a while since I've had to repair anything on the pony. Found out that most of my genuine Ford parts bookmarks are no longer valid. Need to find a new retailer that is trustworthy and economical.
  4. Tousley Ford here in MN gives 10% over cost to forum members on SVTP and ModdedMustang... you could just call and ask for Kevin and tell him you're on one of the forums. He'll ship right to your door :nice:
  5. Got my first SES light today for this car since I bought it 9 years ago.
    P 0171 Bank 1 lean
    p 0174 Bank 2 lean

    I removed the tubing from the IAC to the PCV valve and covered the port to the IAC with duct tape.
    Then I started the car and the issue of the hanging RPMs has stopped.

    Upon closer inspection :rlaugh:(you will see why this is funny in a moment) it appears that I do indeed have a vacuum leak.


    It's the 90* elbow from the tube that comes off the PCV valve just in front of the IAC valve body.
    Now where can I get a replacement for it??
  6. i had a similar situation a few weeks ago. youll need to go to a parts store and buy a random vacuum hose they have in stock that has a right angle with the right diameter measurement. youll just have to cut it to fit
  7. Yeah, I have taken the rest of the tubing off so that I can use it at the store for fitment. :nice:
    I saw that The stealership wants $40 on average for the tube assembly which consist of a 12" plastic tube and 2 of those 90* rubber ends. :nonono:
  8. Well I found a high heat 90* coolant elbow for $5 at Discount Auto. It's not perfect, but it will work until I find a PCV elbow that is gas/oil resistant.

  9. You should be able to find a preformed fuel line that is that size. Like mentioned before, you just have to cut it to fit. If you can't find it at the regular part stores, they should be able to order it. Diesel shops should have that stuff on hand.
    Jinx likes this.