A friend of mine has an 05' F150 with the 5.4 Triton. A few months ago he was getting misfiring readings from a couple of the cylinders. We changed the plugs which was a chore after finding out why the tool is available for broken plugs. The code went away.

About a month ago the fuel relay module needed replaced.

He's getting the code again for cylinder 7

He pulled his plugs, they are burnt from his description. He cleaned them up but is debating replacing them all again. The fuel filter had brown fuel coming out of it when he changed it to see if it would fix the problem.

The probem: He was pulling his trailer then seemed to lose all power. When he drives it is like he doesn't have power and gets a max of 20 mph. I am suspecting not getting enough pressure at the fuel rails and he is thinking maybe there is a problem in the transmission.

Not sure what it is really. He's ready to take it to the shop as he needs it being self employed. I don't really blame him, but if it's something that can be found quickly and easily I would rather him save that money.

 

He replaced a coil and it got rid of the one problem but it is still having issues as seen below.

 

Ok it now has a shutter and runs a little rough. He replaced only 2 of the 8 spark plugs but has the others. He went to take it around the block and it died on him. Any help would be great. Could it be not enough pressure from the fuel pump?

 

Get a mechanics stethoscope. They're about $10 at a parts store and you can touch it to your coils and hear better if they are having problems. I had a similar issue and it turned out to be either a bad plug or a plug not tightened properly. Either way the plug was completely burnt and missfiring. Causing all kinds of power loss and shuddering.