LandArch

This started about 6 months ago, it happens sometimes when I start from a stop position but most of the time its associated with the following. When I am cruising along, really no matter the speed, then slowly depress the gas pedal to maintain speed or slightly accelerate I feel like I am on a bucking bronco.

At first I thought it was a dirty fuel filter, no dice. Then I changed all the plugs and spark plug boots, loaded them up with dielectric grease as well. No codes are being thrown and its driving me insane. Everyone that I talk to is stumped. Any thoughts?

2002 f-150 XLT Supercrew, just shy of 100k. I love this truck I need to get it corrected. Any thoughts would be greatly appreciated!

Ice-Cable

It could be U-joints, but none of the U-joints I have had go out, feel like a "bucking bronco". It has always been a shudder, or a vibration, no bronco......and if it is the u-joints, then it wouldn't throw codes either.......

harley9703

Buy all 8 new coil packs, basically when your putting your truck under a load, a coil/if not some are breaking down.

stan2973

Have you tried cleaning the IAC valve? Mine did a similar thing and I cleaned it and it went away...so I knew what to replace. Just a thought.

ryanroma

Hate to be the bearer of bad news but it MAY be in the transmission. Mine started doing it and I took it to the shop and they checked it out, metal shavings were in the pan so they took it out and 1/4 apart, only because the parts had fused together and stuff and the truck was trying to shift into 2nd, 3rd, and reverse at the same time. Ended up costing me $1500 to replace all the electronics associated and internals.

Kattumaram

The MAF has gone south. My granddaughter's '94 Ranger was a bucking horse and, although I found it hard to believe, the MAF was bad. Go to a salvage yard and pick up the sensor module from a like vehicle and give it a try, or spend ~$110 for a replacement at Advance Auto.

dhunter300

it sounds like 1 or more coil packs r bad! thats the same thing my truck was doing. it was 1 coil pack

LandArch

Update: I don't know if this might make a difference on anyone's diagnosis, but I noticed that it seems to always do it around 1500 rpm. Also when I replaced the boots and plugs last weekend one smell substantially different than the other, Maybe I will replace that one first. Is it possible for a coil to be going bad like that and not throw a code? If it is a coil or two, whats the best to get? I picked one up from the dealer, 110 bucks later I am hesitant to open it since I might return it.

I appreciate all the suggestions, I will most likely work through the list and see what happens. I will leave the tranny to last though, I am going to pray that it is not that since I had one go in my 93 F-150. That hurt big time.

cbf150

Im going thru the same thing right now. I replaced all plugs and plug wires, coil packs. A major tune up. I checked fuel pressure, and it was low. I changed fuel filter, and air filter, Checked emission system components, and still no dice. I may be looking at replacing fuel pump. This is my first Ford and probably my last!

jdf150

its not Ford's fault that you replaced a bunch of parts that didn't need replacing.