Ive posted here a while back, i have a 2004 F-150 5.4 3v 4x4(i know its not a 4.6 mustang) but with similar design i thing you mustang guys can help me. I have done a FRPP "hot rod" cam swap a while back and have been driving around with it for almost a year now, the engine shakes at idle speed, but cannot find and vacuum leak and the truck has great response and power gain from the swap. I even pull a car trailer loaded down with atvs and it pulls better then stock. I have more upgrades that have gone along with the cams such as CAI, Long tubes, full magnaflow exhaust, 24# FRPP injectors, accel coils and so on. The motor was fully torn down and installed melling hf/hv oil pump, MMR tensioners and guides, FRPP rocker/lifters. And tranny "4r75w-4x4" was upgraded with 2200 stall, stage 1 Raybestos clutches, and "custom" trans-go shift kit. I still have not installed the 4.11 gears yet, but i would like to see if i could get a dyno tune to see if that may fix my idle shake issue, it idles around 680-750rpm with no big surges on 87oct, but runs the same if not better on 89oct. So if anyone has any suggestions on either a fix or a good dyno in Louisville, KY that be great, thanks in advance and sorry for rambling.

 

You changed a major major engine component and didnt tune it for a year while beating around in it ? First thing you should have done was get it tuned

 

the truck has an email tune from Power Hungry Performance, they have done research on the 5.4 2v and 3v and have been great so far but i want more fine tuned, due to PHP being specialized to Ford diesel performance. Sorry for the late reply

 

Definitely not a "fix" thing. You need a dyno tune. Can't help you in that department but, just iterating what the ideal solution is.

 

The engine is not going to idle smooth with those cams in it. It is supposed to have a bit of chop or gallop.