4.6 to 5.4 swap

[SmallTownFool]

Hey all. A good friend of mine is doing an engine swap as the title implies. This project as taken roughly 3 years. He did his homework and done the work properly, moving and rerouting all the necessities. Such as PVC lines and coolant lines. He also replaced maf with the 5.4 part number. The problem is on his first test drive it ran good but all of a sudden it bogged misfired and now runs poorly. Now the problem is the engine light came on and we can not scan it. I have searched throug this forum and have came up empty. I have checked fuse 41 and it is good. Is there any other things we can check in to????

 

[stamp11127]

Why can't you scan it?

 

[SmallTownFool]

The scanner we have just will not link up to it. It links to everything else, just not this one.

 

[stamp11127]

I would find out why it doesn't connect first. That way once you have the codes it will be quicker to fix.
PM me an email address to send some info to help you out on.

 

[k_aimone]

Have you checked the OBD fuse, or is that the 41 you mentioned

 

[stamp11127]

Need some basic info -
Year we are dealing with?
What all swapped when the 5.4 went in, sensors, harness etc?
Any mods done during the swap to make it work?

Going to assume you have access to a meter & test light...

Is the scanner not powering up or not communicating with the pcm?

 

[SmallTownFool]

The truck is am 03 xlt. He used the stock 4.6 wiring harness and PCM. The only sensor that was replaced with one specific to a 5.4 was the MAF. The only other sensors replaced were damaged. The throttle position and the idle air. The only modification was an oil filter relocation kit. The scanner powers up right up when plugged in. There is one pin in the ALDL that has no power or ground. Also I just learned that my buddy dropped the PCM during all the work he was doing. Probably the cause of the problems but not sure.

 

[stamp11127]

Sent you an email.
Check the connector pins on the pcm, looking for broken or bent pins. Handle with care....