Hoping someone can give me an idea. I changed out the fuel filter thinking I had water in the lines as the truck was hestitating/"jerking" from time to time. It did not improve. Today it started "jerking" (in lack of a better word as I do not know the terminology) going uphill, seemed like it wanted to stall. The service engine light came on, was blinking. Then it disappeared. Any ideas? Fuel pump? Or is it worse, i.e. transmission or something. Thanks.

 

Go to your local pep boys/autozone/other shop and see if your vehicle is throwing any codes. Is it jerking when you have your foot slightly on the gas and your tach is around 1.2K? Mine does that also quite often, and it is fine if I stomp it up to 3K or just take my foot off the gas completely. My truck only jerks, the check engine light is always on from a bad EGR valve that has yet to get fixed...

It seems like its pushing to accelerate just a slight bit, like 1MPH more than your going and once you reach that speed, it lets off quickly and than when it slows down in half a second it reachs that extra .2MPH and does this over and over again.

 

I agree with the above. Check for codes first. You will probably find a coil or spark plug is intermittent under load. It takes more to fire a spark plug under load so any weak point in the ignition system will be revealed under duress.

I washed my engine in preparation for a spark plug change. I've done it many times before so I was not worried. But she coughed and sputtered going up mild hills such that I drove straight home before cooking a catalytic converter. Everything online pointed to a bad coil.

After checking coil prices I decided to go ahead and change the spark plugs first then see what other issues remained. After it was all said and done, she started up and ran flawlessly and needed no coils replaced. I suspect some moisture got up where it is not supposed to and cause an intermittent short. Dielectric grease should help here.

Pulling codes will at least tell you which cylinder is at fault. I suspect a bunch of coils get replaced when they really have connection problems. So my recommendation is to clean and grease all connections first before changing an expensive coil. before you reinstall, clean and inspect the whole boot since they are replaceable; any weakness will allow a path to ground which will result in a miss.

I hope this helps.

Surfinmutt

 

When I got my '01 expedition I was told they replaced a coil pack that fixed a hesitation problem, but it happened to me again. I replaced the 02 sensor in the cat and cured the problem. A little over a hundred dallors and it screws into the cat like a spark plug, just don't touch the end of the sensor, it will pick up oil from your skin.

 

Something else to try.......Look for spark plug wire arcing to another wire or to ground on a really dark night.... If it looks like 4th of July when you race the engine (using the butterfly valve, of coarse)... then time to change them...

Also get you codes check like mentioned above.... a check engine light for a misfire (that comes on than goes off during really rough uphill driving) most likely a bad plug or COP..... but at least the misfire tripped the light... One of the most frustration thing is having a misfire, but no codes to pinpoint the cylinder.

Seafoam in the gas tank and directly in the intake seems to help, but sometime "fouls" the plug if it pushes alot of crap downstream into the pistons...

Check vac lines. Check EGR Valve function.

A fuel line moisture remover additive has helped me in the past... only a few dollars to try if you have water in the lines...

 

Sounds like the problem I just had with "97 Expy. It was the #5 COP and spark plug. But, like the other guys said check your codes. That's what pointed me in the right direction.

 

I have this problem exactly with my 03 Expy. Its been 30K since I changed the trans fluid and filter, so I did that today, no change. Has anyone found the solution for this symptom? Thanks,
-Paul

 

The jerking/hesitation is almost certainly due to one of the COPs. Most likely the insulator has cracked and is shorting out causing the jerk/misfire. Changing the plugs and the insulators will likely correct the condition. Pulling the codes will probably allow you to pinpoint which cylinder is the culprit. The insulators are inexpensive, but the job to replace them is nearly the same as a full tuneup so why not change the plugs at the same time. A aftermarket set of COPs can be purchased on e-bay for a little more than $100/set, I assume they already come with insulators.

By the way, I had the same issue on my 2003 and the insulators and new plugs solved the problem.

Good luck.

 

Thanks for the advice, after some more research yesterday I'm leaning toward a misfire as well. I saw the $100 set of COPs on ebay, but I'm wary since Ford gets $140 each and $60 at Autozone. I think I may start with plugs and insulators and see if that cures it. By the way...Are you using the platinum plugs or iridium? Thanks,
-Paul

 

It probably is just the plugs and insulators. From what I've read most people have had good luck with the sets purchased off e-bay. I have not changed my own plugs (done by the dealer) but I know the people on this board mostly recommend staying with Motorcraft plugs. Make sure to use lots of dialetric (sp?) grease on the connections between the COP and plug.

 

I purchased the $100 COP's off eBay almost a year ago, as well as a set of the Motorcraft plugs in preparation for having my plugs & COP's changed. The eBay COP's have performed flawlessly and I would recommend them.

 

2001 expedition 5.4
I'm having a shudder under power between 1000 and 1800 rpm. I have the service engine light on with error code p0171. Lean bank 1
I recently had a misfire #2 cylinder which I replaced the cp and it ran great for about a week.
It has a passenger side exhaust manifold leak on start up.

I have also replace the
fuel filter
egr valve

any suggestions would be great.

 

I Googled your error code and got these types of findings:

These are lean codes. This means there is not enough fuel to mix with all of the air that is entering the engine. This could be a problem with fuel pressure, vacuum leaks, or a dirty MAF sensor heating element. 9 out of 10 times, it is the MAF that needs to be cleaned, so start with that.

Luckily, I have not had this issue (yet).

 

Forgot to post an update on this one. The plugs and insulators were the cure, ran like a champ immediately afterward. Highly recommend blasting out the plug recesses with compressed air, mine had lots of dirt and sand that could have otherwise fallen into the cylinder. Thanks for all the great advice guys.

 

i have a 2002 f-150 5.4 v8 and i seem to have the same problem at 1200rmp and 1800rpm bu tmine only does it in the summer time and usually after its gets hot and it will only do it form about 43 to 50mph any suggestions ive had my whole rear end done and the drive shaft has been balanced twice i'm stuck on where to go i believe i had the plugs replaced at around 80k and im at 116k right now. also my check engine light hasnt come on and ive put the black n decker scanner on it but nothing came up.