I have a 98 f150 4x4 lariat and drive it everyday on our farm. I dont drive it really hard. But last night i went out to talk to someone and when i fired the truck back up i felt it shaking. It was very odd cause i maintain the truck pretty well. I recently replaced my spark plugs (bosch 4 prong platinums) but still running the stock plug wires. But im just trying to figure out whats going on with my truck. I know she bucks alittle while driving because i have a damn helicoil in her and i cant for the life of me get it out to change that plug. but i think i might have to get all new wires? Please help lol

 

get those plugs out of there and put in OEM Motorcrafts with new Motorcraft wires. these engines are very picky about ignition parts and only original Ford parts seem to satisfy them.

 

Alright i can do that. Thats not a problem. I've had this truck since 07 when i graduated high school. I had to replace the ball joints but that was the only thing i had to replace. but i put those bosch plugs in there in the winter cause i noticed the truck wanted to backfire when i got on the gas. that curred the problem for a bit. but now she started jerking again when going down the road. and its gotten to the point of the motor vibrating harder than usual motor vibrations.

 

Any check engine light on ?
Sounds like you have a misfire..........

 

affirmitive.. the check engine light is on.

 

from what im learnin on these trucks sounds like you might have a coil packin takin a dive on ya.. id pull those codes and see what it says

 

first start with plugs and plug wires. use only motorcraft parts.

simple thing to do and may be all you need.

 

1st get the CEL checked to see what code('s) you have. Definately sounds like a misfire problem. If a random misfire code comes up, change plugs and wires. If the wires are original get them changed ASAP.
I just fixed a truck with simular problems, the codes read lean on both banks, plus random misfire code. I put new plugs, wires, (way over do on both) and fixed a vacuum leak. Truck runs great now with no CEL coming back on and greatly improved MPG's. Keep in mind, I used MOTORCRAFT PLUGS. I have always had good luck with Beldin "Super-Blue" wires, from NAPA. There will be other's on here who will state to use only MotorCraft wires, I respect their decision's but I have good luck with the Beldin's.

 

My 98 started running rough on start up when coolant started leaking into cylinders...head gasket.

 

Bosch plugs are the WORST plugs you can put in a Triton. Get a set of Motorcraft SP's in there, disconnect the battery for 20 minutes to clear the codes, and go from there. If the CEL comes back on, go get the codes read. Be prepared to replace the plug wires and maybe one or both coil packs. Check for vacuum leaks, especially the PCV elbow behind the intake. To avoid plug blowout, run the new ones in dry (no antiseize) and torque them to 28 ft/lb. Use dielectric grease in the plug wire boots.

 

I am having the same issue with my 1998 4x4 / But i need a diagraham of the plugs and wires! Can u tell me wher to find this online for free?

 

https://www.f150online.com/forums/v8...gs-can-do.html
noones is sure what happened to the valve, just look at the plug. bosch plugs=junk
and yea, you need to find out what the codes are. make sure you post the actual code number and dont listen to autozone telling you what you need if they scan it.

what do you need a diagram for? wire routing? where everything is?

 

There is no need for a "wiring diagram"
The easiest thing to do when changing plug wires, is to pull one and follow it back to the coil and mark it's spot. Draw a picture if you need to reference back to somthing. If your like me, I like to pull all of the plug wires to get them out of the way. If I don't own a Haynes repair manual for the vehicle I'm working on, I draw a quick diagram to reference back to. I have never cross wired plug wires using this method.

Below is your cylinder layout looking from the front of the truck.

4 - 8
3 - 7
2 - 6
1 - 5

# 1 cylinder from the front of the truck, looking at the engine, is front passanger side.