recently replaced the 5.4L 3v engine in a 2004 f150, have everything in also replaced the starter. Got it in and ready to fire her up and nothing just a click, positive battery wire is getting hot, diconnected changed ground wire, inspected wires all a go, took new started to get tested and was bad so replaced it.. Currently at my wits end on where to even begin to look after inspecting everything I could think of, have been trolling this site while I put engine in.. Now looking for some help

 

are all of the wires connected , good ecm?

 

It was a loose connection at the transmission, now back at square one, engine has no get up and go as before replacing engine. So I am currently checking vacuum lines, almost everything has been replaced on the truck so its very frusterating.
It drives yet the brakes are tight wont stop good, I have driven maybe 10 miles on it so far trying to get all the leaks out and such.
Yet as I stated back to square one, prior to engine replacement there was no power, lack of idle and it was bucking. Now the bucking is gone, and it will idle better great power at low speeds yet when accelerating feels like I am towing a semi.
Any help would be great.
Also looking for a vacuum diagram

 

If it lacks power at wot it may be a fuel supply problem. Can you put a fuel pressure gauge on it and drive it?

 

Fuel pressure all good. Sprayed engine and do have a vacuum leak in process of trying to fix that and see how it does, if I cant find it will take intake off again and make sure it isnt cracked.

 

The bucking was prob a bad spark plug and the lack of power is prob a bad cat converter from the bad plug. The brake booster vac line connects to the bottom of the intake at the back and can be a PITA to put on. If that is not hooked up you will have no power brakes and a large vac leak. I would start there before I pulled the intake again. Also loosen up the exhaust where it connects to the manifolds and see if it has power. If it does, then you have a bad cat.

 

Your old sick engine probably cooked a cat or 2. X2 on vacuum leaks, easy to miss and hard to find. An unlit propane torch will smooth out the idle if it is a leak. The MAF and intake pipe are also suspect, but you should see a Code. Code reading is good at this time for a faulty catz or O2. The Pids can take you to suspected problem answers driving in real time. Look for abnormal 1's vs 2's and extremely high values.