Hi Folks-
1997 F250, 5.4, auto, 4x4, 70,000miles. The check engine light started flashing and the truck started bucking. I was going about 35mph. It seems to idle fine but if I punch it it seems okay sometimes and other times it has little power. I haven't wanted to drive it to town for fear of not making it (chicken, I guess).
Low speed seems fine. Thanks for any help.

 

Sounds like a bad ignition coil. Just got my F-150 with the 5.4 V* back from the dealer with the same problem. Cost me $236 for replacing the #7 coil and a spark plug. Charged me $121 for the coil itself. AutoZone sells a similar coil for 40 bucks so you choose...oh, this is my second bad coil. First one was covered under warranty at 30,000 miles (#3) this one (#7) was at 67,000 miles. 6 more coils to go and I'll get to start over again.

 

Have you drawn the code yet?

Good luck,
Doc

 

Haven't gotten the code yet. Didn't want to do dmage driving to Auto Zone, 15 miles

 

Have the spark plugs ever been replaced? Fuel filter?
It shouldn't do any damage driving it to get it scanned and then you'll at least have some idea where to look for the problem. Write down the code number and not just the description and post if here. Someone will have some ideas.

 

Got the codes, 442 (small evap leak), 304 (misfire cyl 4). Thanks

 

Check the heater hose above the #4 coil for leakage. If any sign of leakage is noticed, install a new clamp on the hose and replace the #4 coil.

 

I'm having the same problem with my truck. It is exact same truck only exception is the comp says my evap leak is large. But it's been that way for about 8k miles. Then the bucking started to happen. I had the plug replaced and it wasnt fixed. Gonna replace the fuel filter today. Does anyone think it will fix the problem or is there something else I should look for?

 

Mechanic insisted it was plug, changed it, no better. Changed the cops and all was well.

Good Luck-- nancyjack

 

I had to replace the # 3 coil on my '99 F-150 (5.4L) at about 80,000 miles. It cost me $40 at NAPA and the part they gave me was a Motorcraft part (the only difference from the OEM coils my truck has is that the Motorcraft stick on the NAPA part has a green sticker whereas the factory coils have yellow Motorcraft stickers).
My truck developed an engine misfire, replacing that coil fixed the problem.
Octane

 

Had a similar problem on my 97 F150 4.6 - turned out to be a sticking EGR valve.

 

A sticking EGR valve might have given you similar drivability concerns, however, it would have given codes that related to the EGR system, not a single cylinder misfire or an evap system leak.

Steve

 

HI All Im having the same problem how do i find out witch coil is bad?