I've read "P0304 misfire" threads until I've passed out.... I'm thinking about sticking the '70 351 CJ spare into my truck...

1997 F150, 4x4, 4.6 w/205,000 miles. Nice tight truck but a misfire in #5 cyl. Paid $3500 as is so even if I have to throw another $1000 at it I may be doing good.

Not sure of the history of the truck. Lot porter kid at the dealership told me it was his dad's and they just decided to buy a 2012 F150 and keep it for 13 years like this one. I asked him about the misfire and he told me it was in #5 cylinder and when I got home and ran the OBD sure as heck, I got a P0305. The kid told me that his dad and him had determined that the problem was the "connector to #5 injector" so I'm going to stick a noid light on that connector and see what I get.

I'm very happy to have read the many posts regarding the spark plug removal proceedure by the way... cold engine, carb cleaner soak, wiggle etc. as per Ford TSB. So I will be pulling that plug to take a look. The plug wires look to be original as well (!) and having misted H2o on the wires and not seeing any arcing I'll probably still replace the plug wires. Coil packs rarely fail on a single cylinder so I won't be going there. I already have a new set of Motorcraft Platinums waiting... I'll also remove the front wheels and lower the truck onto a pair of small jack stands to ease access to the compartment without developing a hernia (thank you to the guy that came up with that idea. I still have bruises on my chest from an F350 Turbo Diesel, turbo replacement).

I should also think about replacing all of the injectors with this kind of mileage, right? I'll be replacing the fuel filter as well. $$$$$$$$$$$$$$

But.... I've kinda been dere done dat with a 4.0 SOHC engine in a 2004 Explorer with a P0304... New injectors, plugs, wires & bloody knuckles and only to find out that the engine had dropped an exhaust valve.... The replacement engine got the new injectors, plugs and wires though....

So I'm kinda paranoid about valve train issues..... It would really sucketh to have to replace the engine.... never mind my wife freaking out about me buying another "fixer upper". Do the valve guides regularly fall out of the heads on the Triton engines? I've read a few nightmare posts that described just that and rocker followers that are laying inside the valve cover.

So..... I'm thinking about pulling #5 plug, checking it and the plug boot for carbon arcing, coolant in the plug well, wire integrity, etc....... and THEN doing a compression check on #5 cylinder before I get carried away with a lot of time, labor, blood and $$$ only to find out that I have zero compression in #5.

So for now..... here's a question... Is it possible to get a compression tester hose down into the plug well or do I need an adapter of some sort?

I'm keeping my fingers crossed that it's a simple problem with the injector but.......

 

The 4.6 dont require anything special to get the plugs out. That is the 04-08 5.4 3v engines. No carb cleaner nothing just remove the plug. No anti seize on installation. Torque the plugs to 28 lbs dry. Get the noid light if you getting power your problem is plug, injector, wires, coil (pack) or no compression.

 

Whew! Thanks! I bought the plugs and wires yesterday and was relieved to open the little plug box and find a normal plug...

Still a major PITA to get to these plugs.....

 

You may have trouble pulling the wires off the plugs, when I did my 97 it only had 40,000 mi. on it and i tore two wires. It was as if the factory glued them on, I replaced them with 8.8 MSD wires and they work great I also used Denso iridium plugs. This was done in 1999 I now have 154,000mi. on the truck.

 

I used dielectric silicone grease on the porcelain insulator portions of the plugs and on the outside of the plug boots with the hope that at 300,000 miles I won't be pulling the plug wires out in pieces.

 

Dielectric doesn't make them easy to come out. It helps seal keeping water out. I think after a few years it actually makes wires or plug boots harder to get off. I knnow when ever I pull off my boots its like there glued on.