tcross

im new to the Ford scene and a few weeks ago i bought a 98 F150XLT with the 4.6L in it. for the first 2 weeks i had it drove it around and had no problems with it. the check engine light was on when i bought it but when i drove it before i bought it, it ran wonderful. now for the past 2 weeks its been running like a miss fire so i had the check engine light ran. i cant remember the code it pulled up but it said it was a missfire in cyl 3, or wither high/low fuel pressure. i have been reading diff post on here about what to change and check, i changed the pcv valve, and tomm will do plugs wires, fuel filter, air filter, and will check for any vaccum leaks. does any body have any other advice on what to change or check that isnt to complicated of a job? any advice will be greatly appreciated since i am new to the Ford. thanks in advance

97f150garza

My 97 4.6 also had a 3rd cylinder misfire. I changed all the plugs and plug wires and everything is fine now. I suggest u start with those first. If that doesn't fix the problem it could be a bad coil pack or a fuel injector.

tcross

ok thanks. ya im hoping thats all it is. gona change the plugs and wires and a few other things like the fuel filter and fix an oil leak i have on the oil cooler hose today but hopefully the plugs and wires fix it.thanks for your input though i appreciate it.

llhrpm

hi there, idk if you have read my post about my problem i have it very detailed and explained whats going on with my 4.6 i have the same truck and the same cylinder misfire... today im going to do a test and see if i have a burnt exhaust valve and if that pass's then im going to do plugs and if that dosent work im going to put an injector on

tcross

another thing did you remove the fuel rails to replace your plugs? i was reading a how right up on here and the guy said it makes it a lot easier to do. i was a lil worried about doing it myslef because it doesnt look like the esiest set of plugs and wires to change when first looking at it, and did you have any problems replacing them? thanks

tcross

ya i have read it, ive been reading different post on here about missfires on our type of trucks for the last week and trying to get as much info about this problem as i can. im gona try to do my plugs and wires today but first gona check for some vaccum leaks b/c i have read a lot about that too. not quite sure where and what all to check for the vaccum leaks but im gona keep looking, i just wnat to make sure im checking the right things. but let me know how you make out today im interested to know. seems like a lot of people have the smae problem as us but its not always the same thing but i would like to change as much parts as i can that are not too crazy exspensive so i can put money into my truck for tires and a lift and such but deff want to get it running 100% first. good luck today hope you solve your problem as well.thanks for the reply by the way

garbill2003

World of advice start cheep and work your way up it wouldn't hurt to give it a tune up but ive never seen a spark plug throw a missfire and i seen some really bad plugs

tcross

^^^
ya thats what i want to do before i go dumping a lot of money into it for no reason. i have read a few post when i joined the site a few weeks ago saying ppl changed injectors, and all kinds of stuff and it didnt fix a thing. i would love to do that just to have the piece of mind that everythig is new but for now i just want to fix the problem. any other suggestions on what to change or look at to fix this problem besides plugs/wire, pcv valve, fuels filter?thanks

garbill2003

Ok well let me start by asking were you driving it when the code came up and how were you driving it was their any noise when it came up

tcross

the check engine light was on when i bought it. but i drove it all around before i bought it and there was no problems with it. it ran fine. then after driving it for about a week and a half it started doing it when i would hit about 40-45 mph but if i steped on the gas it would go away. then a week later it started doing it when going up hills too and the problem just started getting worse. now it does it sometimes when im stopped and step on the pedal hard to start goinng it will do it. if i let off the gas when ever it starts to do it it will stop and if i apply light pressure to the gas pedal to keep going it useally goes away, sometimes the check engine light blinks then stays solid.