On my 1996 F150 I get the code P0305, cylinder 5 misfire. I changed the plug and wire. The code came back again tonight. The truck shakes a little bit at idle sometimes , thats the only thing that is not perfect.

Anyone got any ideas? injector ?



Its a 1996 F150 5.0 4x4 auto trans with 98,000 miles

Oh and its got motorcraft platinum plugs, ford racing wires and msd cap and rotor

 

Did you look at the old plug? Did it look fouled? Overheated? Did you inspect #5 post on the distributor cap? Did you check compression in #5?

 

Try swapping those platinums with Motorcraft or other brand's coppers, gap them to 0,044 to further reduce the misfires (if you don't want to do the sixlitre tune up).

 

yes i inspected the cap and rotor, the cap terminals were not any different than the others. and the plug looked just a little white on the tip. Didnt do a compression test.

 

i looked up the six litre tune up. didnt find much on it. Is it just plugs wires cap and rotor and coil?

 

basically, yes.

 

ok thanks, then im set there. I took the wire off my mustang and swapped it to my truck to make sure its not the wire and its good. since its cylinder 5 i think i can remove the injector without taking off the upper manifold. so i was thinking i could swap two injectors say 5 and 6 and see if i get a cylinder 6 misfire and that would tell me if the injector is bad.

What else is there?

 

try that. then if possible do a compression test. a dead cylinder would be odd in a motor that young but weirder things can happen. hmm... only on #5 well another thing you might wanna do is test your ignition coil.

 

if it still does it you might have a bad dizzy. I replaced mine not too along ago. had a miss on #1 and #3

 

Also, make sure plug wire 5 & 6 do not route next to each other. Those two cylinders are next to each other in the firing order and one can induce voltage onto the other causing detonation.

 

whats a dizzy? never heard of that

And i do have cyl 5 and 6 wires ran nextto each other, ill separate it

 

Dizzy = slang for distributor .

 

My apologies sir. Got to use the correct terms next time lol

 

haha thats alright, now i know. Tomorrow ill look more into this ill start by seperating the wires. Im tempted to say its a fuel issue with the injectors, because it shakes only once in a while while idling. other times i cant even tell its running its so smooth