Engine will not stay running after replacing IAC

2003 FORD EXPLORER
320,000 MILES • 4.6L • V8 • 4WD • AUTOMATIC
Avatar
TELWALSH
  • MEMBER
  • 2 POSTS
Hi, I was having an issue with intermittent high idle when idling, so I cleaned the mas and IAC and now the car will fire up but will not idle and cuts out, anything that I may have missed?
Dec 1, 2021 at 7:41 PM
Advertisement
Avatar
KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
It is possible that something was not connected correctly but the more likely issue is the IAC was damaged and now requires replacement.

Not sure how you cleaned it but here is a guide that will show how to clean these:

https://www.2carpros.com/articles/idle-air-control-valve-service

If you cleaned the IAT as well then that may be damaged as they are normally not too happy with being cleaned using harsh chemicals. However, this is not likely to cause a start and stall event. That is more likely the IAC.

I am attaching the process below on how to replace this which is what I would do and then retest the operation. One way to help confirm this is to see if you can keep the engine running by opening the throttle but that is not always definitive because it is not the easiest thing to do.

However, I have replaced enough of these IACs over the years to know that this is the most likely cause of this at this point.

Let us know what you find with this, and we can go from there. Thanks
Dec 2, 2021 at 6:56 AM
Avatar
TELWALSH
  • MEMBER
  • 2 POSTS
Hi, thanks for getting back to me, I will look in to replacing the IAC. could the cleaning have caused this to now be faulty or was just on its way out already?
Dec 2, 2021 at 8:04 AM
Avatar
KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
Could be both. It may have been beginning to fail and the cleaning pushed it over the edge or if you cleaned it with harsh chemicals, it could have damaged it.

Either way, cleaning them is worth the try but most of them end up needing to be replaced as they normally don't present an issue until they are too far gone. So, the cleaning is more of a maintenance item and not a correction when they fail.
Dec 2, 2021 at 11:27 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.