RPM Surge When Pressing Throttle Lightly

[brycelino]

Hello all, my 96 mustang 4.6 2v is experiencing this surge when i just barely press the throttle. i just noticed this. i had a cel for P0171 i replaced an emissions hose. I also clean the MAF sensor and the throttle body. My spark plugs are only about a year old maybe 6k miles on them the looked okay. This doesn’t happen at all during idle and it won’t happen if you just step on the gas regularly. Only when you just barely press the throttle. Has anyone gone through anything similar or any suggestions
Link to video of the issue

 

[96blak54]

We modular nuts are discovering the original plastic intake manifolds degrade with age, including the original intake manifold gaskets which in turn will allow a hidden vacuum leak. With this said if you have updated to a better original Ford intake manifold and new intake gaskets, a certain intake manifold gasket is required and not just some run of the mill 4.6l manifold gaskets. The required 4.6l intake manifold gasket for an original Ford manifold(npi or PI) made by Montaplast requires the thicker intake gaskets made by Fel-pro or Ford(same). These specific gaskets are roughly .040" thicker to compensate for manufacturing warpage of the original 1 piece plastic manifolds. In other words, if you ever have replace intake manifold gaskets with ebay, amazon, or run of the mill 4.6l intake gaskets, you most likely have a leak. How do I know this you may ask?......I worked for the intake manufacture Montaplast and this is well known within the factory. So long story short, hidden vacuum leaks with the original Ford manifolds and original gaskets can have you chasing problems due to age and/or overlooked incorrect replacement parts. Do you know the history of your engine? Has there ever been any manifold work done?