Serious bucking/hesitation problems

[ike1012]

I was hoping to get some help as to what can be the problem I am having with my 2003 Explorer. 6 cyl, 87K. It runs great when cold, but once it worms up, on acceleration, it starts some serious bucking and hesitation. Can anyone point me in the right direction? Coil? Transmission? Not sure if this is a common issue with the explorers and I just bought it approx 3-4 months ago..Thanks in advance!!

 

[vipersinu2]

probaly a bad mass air flow, you can try cleaning it. unplug sensor when it is acting up and see if it runs alittle better. only bye a ford mass air flow. I tried 3 autozones and each sensor made the truck drive different.

 

[matt0248]

Could be a failing coil, failing cam or crank sensor too. All can start to act goofy when they are failing, usually after heating up.

When is the last time the plugs, wires, and fuel filter were changed?

 

[ike1012]

I just did a full tuneup on it right after i bought it. plugs, wires, etc. Had it done at my friendly ford dealership. The odd thing is that whenever it acts up I can never get a code from the computer when I plug the analyzer in...

 

[sethmorgan]

Pull the plug wires from the coil and look down into the coil where the plug wire connects to the coil. Sometimes the little brass contact can come out with the old plug wire when you replace your wires. It will still fire that cylinder most of the time but the resistance readings will be way off if you measure the coil with a multimeter. A long shot but it happened to me with these same symptoms. I bought an aftermarket Accel coil to replace the Screamin Demon I had on there and problem solved.

 

[mctommyt]

Explorer bucking/missing

I was wondering if anyone was able to figure out the root cause of this issue. I have a 2003 Explorer which I recently replaced the engine. New plugs, wires, filter.... I have cleaned the MAF replaced coil with existing one and still same results. I took it out and it was running great for about a month. Now as I am going through town I get a bucking option if I hold the gas petal in one spot. I am just wondering what might be some options or places to start trouble shooting this. I would like to keep this around for a few more years which is the original reason I replaced the engine. I am hoping I don't have to do that so soon.

It acts like a misfire but not sure where to look next.

Thanks Tom