99-04 motor swap

[Fingers]

hello im new here and am having some problems with my 99 mustang gt.
i have just finished up a motor swap.

my mustang is a 99, it had a bearing knock so i replaced the motor and transmission with a 2004 setup.

my problem is that the engine is lacking power. if i drop the clutch i can only get it to chirp before it feels like it bogs down. its showing me symptoms of a vacuum leak.
throttle is not snappy.

my question is, could it be possible that i am missing a major piece to the swap?
did ford change the timing in the ecu or even the ecu between 99-04 or any other changes that could give me problems like maf possibly? or am i most likely looking at a vacuum leak? any other suggestions?

thank you very much for your time i appreciate any help i can get at this point.

 

[the98stang]

if you have a vaccuum leak the idle will be high- most likely above 1000RPM. You can find the leak by waving butane gas around the vac lines....when the butane rushes into the leaking vac line you will hear the engine RPM increase....

 

[squeak93]

To answer your question, ford made no major changes to the tuning or cars in the matter. 99 and 00 had windsor based pi engines while 01-04 had romeo's. The trans also changed but none of that would cause the issues your talking about. Good chance you have something leaking or not functioning properly.

Any codes?

 

[Fingers]

no codes and no excessive rpm...
the problem is it doesnt feel like its breathing properly like a cat would be clogged. un bolted exhaust though and that made no difference. it feels hotter under the hood then it should also. and lacks power.

i just wanted to make sure they did not switch the timing ecu or maf from 99-04 or anything else that would make it not function properly that im unable to think of.

i did notice the transmission was different and also on the h pipe where the o2 sensors are were different. what i did was kept my old exhaust set up and transmission harness, and changed the sensor on the transmission. everything else lined up fine. only other problem im having is it doesnt seem like the toggle switch for the traction control is working. i was thinking that it might be possible that its stuck on and that why i dont have power out of the whole but while driving if i let off the throttle it lingers rather then decelerate.

what is it that controls traction? is it the transmission or the rear end?

also could it be possible that the ecu needs to learn to time correctly? motor has only been ran 5 times around after the swap and no long drives.

 

[squeak93]

The timing tables are pre set. The only thing it has is called adaptive learing (kam memory) for fuel curves. They will effect it a bit, but you'll never notice.

Sounds like you may be having wiring issues as you trac control doesn't matter which motor is in there. Check and recheck that nothing has got hot or touched a heat souce.

Oh, and never run a mod w/o exhuast. Good chance when you did that it may of popped an exhuast gasket. (does it have a leak?)

 

[Fingers]

wiring issues sounds like a possibility but i did not touch the trac control wire. i just disconnected the switch to remove the shifter.

and no i dont believe there is an exhaust leak but i will also double check that as well, thx

i will double check the wiring and for vacuum leaks and let you know how it goes.
are there any suggestions on why it would lack power and continue to rev when i let go of the throttle? its not an excessive rev its just a very gradual decline in rpm rather then the slight snap it should have

thank you for your time