5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
Sponsored by Weld Racing
Welcome to Mustang Forums!
Welcome to Mustang Forums.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
I have a Cobra replica with all Mustang running gear: diff, spindles, rack, engine, trans, computer, etc......
The reason I came here is that you have a technical forum for 5.0s. The other forums I'm on don't discuss engine stuff exclusively. Sometimes, you get decent advice but not consistent. Now that mine is running and I have app 1K on it, I want to tune and discover ways to improve the performance.
My 5.0 is mildly modified: Holley Systemax EFI, 24 lb injectors/MAF, 75mm throttle body, GT40p heads (ported), E cam, BBK 4x4 headers to side pipes, Crane rocker rollers, cold air system to fender well, alum fly wheel. The PCM is from a 92 GT.
My question is: what will cause an intermittent surge +/- 1K rpms? I just replaced upper intake gasket and throttle body gaskets and checked for vacuum leaks. At times, it idles perfectly and lopes like it should. This is my first experience with a FSB and EFI so I am thinking that I may have a computer issue but the problem is on and off so it's hard to get a handle on it.
Thanks in advance,
This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Mustang Forums!
This forum is owned and operated by Internet Brands, Inc., a Delaware
corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford
Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor