High Idle / Surging
Thread Starter
|
New User
Joined: Nov 2021
Posts: 2
Likes: 0
High Idle / Surging
Hi Everyone -
First post. I have a 1999 F250 Super Duty V10 6.8 liter (non-California emissions) with about 289,000 miles that idles high at 1300 rpm and surges to about 1650 rpm every 10 seconds or so. Runs smooth when using the throttle. No trouble codes. I recently cleaned the MAF sensor, cleaned the throttle body, PCV valve, and EGR valve. Replaced the PCV hose, replaced the EGR valve pressure feedback sensor and EGR solenoid. Replaced the IAC valve. Running the A/C while idling doesn't change anything. Cannot find any vacuum leaks. No air is coming past the throttle plates. When it is idling, air is screaming through the bypass hose. I can squeeze the bypass hose and drop the RPMs down to a steady and smooth 650 RPMs. If I unplug the IAC valve the RPMs drop to around 400-500, it stumbles a bit, then dies.
Any help is much appreciated!
First post. I have a 1999 F250 Super Duty V10 6.8 liter (non-California emissions) with about 289,000 miles that idles high at 1300 rpm and surges to about 1650 rpm every 10 seconds or so. Runs smooth when using the throttle. No trouble codes. I recently cleaned the MAF sensor, cleaned the throttle body, PCV valve, and EGR valve. Replaced the PCV hose, replaced the EGR valve pressure feedback sensor and EGR solenoid. Replaced the IAC valve. Running the A/C while idling doesn't change anything. Cannot find any vacuum leaks. No air is coming past the throttle plates. When it is idling, air is screaming through the bypass hose. I can squeeze the bypass hose and drop the RPMs down to a steady and smooth 650 RPMs. If I unplug the IAC valve the RPMs drop to around 400-500, it stumbles a bit, then dies.
Any help is much appreciated!
Thread
Thread Starter
Forum
Replies
Last Post
