Replacing the IAC Valve
#1
Replacing the IAC Valve
I’ve been having a problem starting my 99 F-350 V10 in the morning. It seems to fit the classic IAC diagnosis: lightly press on the accelerator and it will start (the sputters a couple of seconds at ignition and then rev’s up but with no need to continue pressing on the accelerator). This only occurs in the morning. I have NO idle or stalling problems.
After searching this forum I decided to replace the IAC valve. The procedure as described in the shop manual is
After searching this forum I decided to replace the IAC valve. The procedure as described in the shop manual is
- Disconnect the battery ground cable
- Disconnect the electrical connector to the IAC valve
- Disconnect the throttle bypass hose to the IAC valve
- Remove the two bolts and washers, and discard the gasket
- Reverse the procedure for installation
- It appears that disconnecting the power brake booster vacuum supply hose and the main vacuum supply line from the throttle body would provide easier access to the IAC. Is this recommended?
- I tried to pull off throttle bypass hose from the IAC valve but it’s on very tight with little room to get any leverage. Any suggestions?
#2
I have had the same problem with my 99 V-10, but did not replace the valve, just remove it, clean it very good, use some good cleaner and a tooth brush and get all the carbon off it, until it is clean and shiney inside and works smoothly, then just replace it, no cost except for your time. I have had to do it twice now on mine since I bought it new in 1998, last time took me about an hour, the bottom bolt is something else, but it is not too bad a job..
as far as the bypass hose, the first time I took it off from the other end from the valve and removed valve with the hose still attached, then I could work the hose off gently after it was out and away from everything, it is much easier and then easy to replace the hose when you get the valve mounted back again..
as far as the bypass hose, the first time I took it off from the other end from the valve and removed valve with the hose still attached, then I could work the hose off gently after it was out and away from everything, it is much easier and then easy to replace the hose when you get the valve mounted back again..
Thread
Thread Starter
Forum
Replies
Last Post
97ExpGuy
1997-2006 Expedition & Navigator
77
03-13-2022 08:13 PM
jas88
Ford Inline Six, 200, 250, 4.9L / 300
14
06-16-2021 06:43 PM