Forums
New posts
Search forums
What's new
New posts
New media
New media comments
Latest activity
Media
New media
New comments
Search media
Members
Registered members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
SportTrac Discussion
Engine & Drivetrain
Engine shakes and surges in neutral at 3000 rpm
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support Ford SportTrac Forum:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="napierjohn" data-source="post: 1048740" data-attributes="member: 77757"><p>This site has been a great resource for me so thanks guys.</p><p>I have an engine issue I'm hoping a wrench turner or two around here could help me resolve. My 2004 4.0 4WD with 145,000 miles has a strange engine issue. I don't often rev my engine too high but found recently when I rev the engine in neutral it starts to shake around 2800 rpms and gets into a surging mode at 3000 rpms. Under load, though, the truck drives great, even when I hit it hard. It isn't throwing any codes.</p><p></p><p>My question is: What is the behavior of the engine when it reaches the 3000 rpm rev limit? Could the surging just be the effect of the rev limiter?</p><p></p><p>I have ruled out some reasons for surging in neutral and so far I have</p><p>- checked for vacuum leaks </p><p>- cleaned not to dirty ERG valve</p><p>- checked the spark plug wire connections</p><p>- used a small scan tool and can see at 2000 rpms in neutral the O2 sensor oscillates in range, short fuel trims hover +/- 2%, and long fuel trims are low, too.</p><p>- read fuel pressure at 50 psi though spec is 60-65.</p><p></p><p>If the rev limiter isn't making the surges, I suspect the fuel pump but don't want to jump to conclusions. </p><p></p><p>Thanks in advance guys.</p></blockquote><p></p>
[QUOTE="napierjohn, post: 1048740, member: 77757"] This site has been a great resource for me so thanks guys. I have an engine issue I'm hoping a wrench turner or two around here could help me resolve. My 2004 4.0 4WD with 145,000 miles has a strange engine issue. I don't often rev my engine too high but found recently when I rev the engine in neutral it starts to shake around 2800 rpms and gets into a surging mode at 3000 rpms. Under load, though, the truck drives great, even when I hit it hard. It isn't throwing any codes. My question is: What is the behavior of the engine when it reaches the 3000 rpm rev limit? Could the surging just be the effect of the rev limiter? I have ruled out some reasons for surging in neutral and so far I have - checked for vacuum leaks - cleaned not to dirty ERG valve - checked the spark plug wire connections - used a small scan tool and can see at 2000 rpms in neutral the O2 sensor oscillates in range, short fuel trims hover +/- 2%, and long fuel trims are low, too. - read fuel pressure at 50 psi though spec is 60-65. If the rev limiter isn't making the surges, I suspect the fuel pump but don't want to jump to conclusions. Thanks in advance guys. [/QUOTE]
Insert quotes…
Verification
Post reply
SportTrac Discussion
Engine & Drivetrain
Engine shakes and surges in neutral at 3000 rpm
Top