I installed a 2002 4.6L EFI Romeo engine in my 1997 4x4 F150. Original engine was also a 4.6L EFI Romeo. The original computer (TBL2), wiring harness and coils etc. are is being used with the new engine. Spark plugs AGSF32FMF6. K&N air filter, BBK 75mm throttle body.

I have ignition knock at low RPM and when the truck is under load running 87 or 91 fuel. Any suggestions of any what I can do to stop the knock?

 

First off, welcome aboard!

Secondly, and take this with me having no real knowledge of your motor or the electronics associated with it, but it sounds like you need to retard the timing a degree or two.
More knowledgable folks will chime in....

--Mike

 

Mike, retarding the timing on this particular engine would require taking the whole front of the engine apart and figuring out a way to move the crank cog enough and keep it there...

I would try some fuel system cleaner, like Sea Foam, to clean up the combustion chamber.

 

Sounds like it's running lean. Have you tried some injector cleaner? I've seen the Chevron Techron stuff work pretty good, it cleared up the check engine light and pinging on my dad's 2000 silverado.

 

[QUOTE=Mattsbox99]Mike, retarding the timing on this particular engine would require taking the whole front of the engine apart and figuring out a way to move the crank cog enough and keep it there...
[QUOTE]

Hence my disclaimer for lack of knowledge

The Techron stuff does work well, I have used it previously and would gladly recomment it too.

--Mike