I recently rebuilt the 4.6 in my 99 F150. After installing the engine it shakes at idle and has no power. I do not have any dtc's. The engine is not running on cylinders 1,4,6,or 7. I have spark to these cylinders and the injectors are firing. What could cause this problem?

 

That is a coil pac model, right? re-double check your firing order and plug wires, not to bag on ya but it is a very common mistake. Start from square one.

Just because there is fire at the plug doesn't mean it's there at the right time, it will fire even if it's the wrong cylinder.

just my $0.02
good luck.

 

I have checked the wires several times and they are as they should be. I have been reading on here that these engines run best on Motocraft plugs so I replace the new Autolites with Motocrafts which made no difference. I have replaced the crank and camshaft sensors also and nothing changed. Any other ideas?

 

Sounds like your timing is off. Did you remove the timing chain and if so is it back on correctly?

 

Autolites ? - Yea some engines will tolerate them, some won't. It's a roll of the dice whether they leave you stranded or not; why chance it ?

I went 40 miles with a new set of 103's/104's. By the time I made it back home , I was running on 6 cylinders.

Pulled the plugs and upon inspection, - the plugs heated up so much , they turned colors.



Advise - Install the OEM Motorcraft Plugs

 

Yes I had the timing set out and installed all new gears and chains. I installed the the set the way that Alldata said to. Maybe I did something wrong. Can anyone tell me how the to set up the timing set on this engine? It is the Romeo 4.6 if that makes a difference.