hey guys, its a 99 e250 w/ the 5.4 and 171k on the clock.

its been hesitating/stumbling lately, and it threw a code for cylinder misfire in #3.

i have since changed out all the coil packs and spark plugs, it feels like it runs better and has more power, but it still feels like it stumbles right on takeoff and on the freeway, but only in overdrive. if i turn overdrive off and give it gas, it feels fine. also, it seems to only do it in 1/4 -1/2 throttle, anything above that it feels fine.

cruising on the freeway at 55-60, it hesitates.

what do you guys think? have changed the fuel filter a couple months ago. should i run some fuel injector cleaner through it?

 

injector cleaner in the tank doesnt work to well. u should take it and get the injectors directly flushed from the rail if u want to clean them. have u changed the fuel filter or transmission fluid?

 

I'll bet he still has a bad COP - Infact , I almost sure of it - just no light yet..

 

betcha a dollar...

 

I'll raise yuh- 2 dollah

 

timinos, as soon as it starts to hesitate - get on it, floor it to produce a light..

 

i have tried, right when it hesitates on the freeway, i floor it, it downshifts, and it feels like nothing's wrong.

you guys still think it has a bad cop? i just changed all 8 of them. no light yet.

i have changed the fuel filter and transmission fluid about 25k ago.

when i pulled the #5 plug, it had a bit of oil on the upper half of the plug(the part thats not in the combustion chamber).

at first, when i threw a code for misfire in cylinder 3, i only changed the coil in cylinder three. but then later, it threw a code in cylinders 3,7,8 i changed all the plugs and changed all the coil over plugs.

i don't know what else could be wrong with it, maybe it's time for a new van

 

i guess i'll just drive it around till it throws a code again. in first gear it seems like it hesitates, but i can't really tell. maybe i got a faulty cop.

 

Nah,you don't need a new one, unless you want one lol, you might still have a weak COP - it's common that a new one could be bad which it sucks how common it is..All you can do at this point (without a light)is make sure your MAF is very clean and the air filter is new and clean you throttyle body and elbow (all the ports) ..

If it's not a COP , boot or plug , that motor should run awesome after all that..

 

sounds like you have gone through this before. haha.

how do i clean the maf? i had the entire air filter assembly off and there were these special torx bits with indents that came up so i couldn't loosen them. are these special ford bolts?

i have heard to spray the maf with brake cleaner. how do i clean the throttle body and intake elbows?

thanks for all the help so far jbrew.

 

check the EGR valve.. take a wrench and tap on it. it could be stuck open

 

You said there was oil on the plugs...Since you have changed them have you checked them again. Do you know if it is getting on them from above or from inside the chamber? I know you can fry a plug and COP the second crap gets down inside there from not getting seal up tight. Also if you are getting oil on the plug from inside the chamber you may want to do a compression check...rings may be worn down. About Jbrew's comments...I had the same problem with my 5.4, and just replaced them and my fault is gone...for now anyways.

 

Well , if you have a pair of vise grips (that's what I used) you can break them loose with those. try to twist without bending - they will break off if your not careful. Replace those screws with user friendly ones once your successful..

Clean with brake cleaner or you can get some MAF cleaner if you want..

If you have an air compressor - use about 10lbs of compressed to dry for best results..



To clean your throttle body - heres some help -

http://www.fordf150.net/howto/throttlebodyclean.php

Wow ,Heres a link for cleaning the MAF , never seen this one yet , but it's good.-

http://www.fordf150.net/howto/clean-...low-sensor.php

 

I have a simular problem with my 2000 F150. I changed the plugs around 100K, and now have around 120K on it. I am new to Fords and have no idea where to start. In reading the posts I assume that my hesitation could be the cop's, or the injectors, or the fuel filter. Where should I start? Where is the fuel filter located?

 

I was going to start another "Stumbling/hesitation" string but might as well tag onto this one. 2000 F150, 5.4l with 140k. Only symptom is will idle rough, stumbling quite a bit but only at idle after warmed up. Has just been serviced by mechanic after finally throwing a code for bad cop and other codes. This is like 3 or 4 cop in the last 2 years. At this time found broken tensioner causing wear through valve cover. All this fixed and after full tune up and clean up of intake track it still does it. It won't throw a code and mechanic sais no pending codes as well. He's contacted Ford and they've suggested I get computer reflashed. Local guy can't do it so it would involve taking it to Ford. What do you take of this? Only stumbles at idle and only once warmed up. Runs perfectly fine otherwise with plenty of power and no other hesitation.

ricochet