I just bought my FD and noticed a problem with it. When im on the throttle it doesnt act up, but when i leave off or hold it steady the car bucks around something terrible. Has anyone here ever had this happen and if so could you help me out with it? Keep in mind, it doesnt do it all of the time, and sometimes not at all. Every now and then the check engine light will come on as a result of it, but the car runs perfect while the light is on. ?????? Any help would be great. Thanks

 

This happend to me and I replaced the o2 sensor with a bosch universal one. Fixed the problem right away. If not, you may want to check your TPS

 

bucking is also known to come from bammer grounding...one to check is next to the firewall.
pettitracing.com sells or gives away free a grounding kit.
maybe check spark plugs as well

laters!!!!

 

My FD does the same thing. I have a PFC and I checked the O2 sensor voltage and the numbers were all over the place. I say new ground and new O2. I'm using the Bosch right now...it's a good sensor, but they don't last forever. Oh, and a bad ground will make U run way rich. If your car is running way rough at idle and U see black smoke from the exaust...normally a ground prob.

 

I had the same problem a little while back. IT;S THE GROUND. Double check all your grounds. I mean unscrew the bolts clean the serface and tourqe it down. Replace any grounds that don't up to par. This should solve the problem. And your bucking Bronco should return back to the Stalion it really is.

 

Wow thanks all! I just replaced the o2 sensor the other day and since then it really hasnt acted up. Today I will check my grounds as well seeing as how it has sat for a few years before i bought it. Im new here and that was my first post. I must say the people on this forum are very helpful. Im glad there is a place like this for us on the net.