F-250 V-10 engine miss

Keith Molden · Dec 17, 2009

My 2000 F-250 with a V-10 engine developed a dead miss on #5 & # 10 cylinders & we can't seem to locate the problem. We've tried new coil springs & boots to the plugs, tried a new injector, pulled the valve cover on 1 side to check rocker arms. Checked for vaccuum leaks & found none.The test equipment shows no miss fire on any cylinder. Compression is 150+on all cylinders.I have it in a repair shop & the mechanic is usually pretty darned good, but he can't find the problem.I was pulling a pretty heavy load on my gooseneck when the miss developed.Just wondering if anyone has any ideas as to what it could be.Thanks, Keith

bradk · Dec 17, 2009

Are the injectors pulsing? You replaced the coil boots ,but what about the coil itself?

Coil-on plug Fords eat up coils pretty regularly.

How did you check for vacuum leaks? Using scanner and carb cleaner,right?

ted regentin · Dec 17, 2009

I assume that your tech has a good scan tool. Have him go into global diagnostics and go to mode $o6. Then go to either mode 50 or mode 53. Then he can count misfires. A lot of times that will help nail down the problem. As I remember that system is coil on plug. Did he try moving coils around and see if the miss moved. Ford has had a lot of problems with coils. Some techs if they find one bad coil will change all coils.
Hope this helps,

oldnnew · Dec 17, 2009

How do you know it's cylinder #5 and #7? I would put my money on a bad C.O.P. Go to your local parts store and buy one. Install this new one on each cylinder, starting with #1 until you find the bad one. If you find a bad one and still have a miss, buy a second one and repeat the procedure until you find the second bad coil. It is relatively easy to do since these coils can be replaced in a matter of minutes. I did this to my Ford 5.4 and it was an easy repair. Coil #3 ended up being the bad apple.

Keith Molden · Dec 17, 2009

When we first put it into the shop it read missfire on #5 & # 10. We have changed coils out with different cylinders with missfire staying on those 2 cylinders. I bought a new injector, tried it & the miss is still there . The scanner however now reads no missfires. He checked for injector pulsing & K.

noncompos · Dec 17, 2009

If this turns out to be a real puzzler, two suggestions:
Review some Ford forums for similar problems and, hopefully, the fix;
See if your tech/shop belongs to IATA (Int"l Auto Tech"s Assn?); it"s a professional techs only group that has it"s own forum, just like this one, for the same purposes.

200cs · Dec 17, 2009

(quoted from post at 06:56:42 12/17/09) My 2000 F-250 with a V-10 engine developed a dead miss on #5 & # 10 cylinders & we can't seem to locate the problem. We've tried new coil springs & boots to the plugs, tried a new injector, pulled the valve cover on 1 side to check rocker arms. Checked for vaccuum leaks & found none.The test equipment shows no miss fire on any cylinder. Compression is 150+on all cylinders.I have it in a repair shop & the mechanic is usually pretty darned good, but he can't find the problem.I was pulling a pretty heavy load on my gooseneck when the miss developed.Just wondering if anyone has any ideas as to what it could be.Thanks, Keith

What is the compression on that engine. You may have an internal problem like a headgasket.

RusselAZ · Dec 17, 2009

Try new ignition coils. common bad on this engine style. (4.6, 5.4, and the 6.8 liter)

if the computer sees mis-fires on a cylinder it will shut down the injector for that cylinder to save the convertor.

504-1 · Dec 17, 2009

Did you try new plugs?

F-250 V-10 engine miss

Keith Molden

Well-known Member

bradk

Well-known Member

ted regentin

Member

oldnnew

Member

Keith Molden

Well-known Member

noncompos

Well-known Member

200cs

Member

RusselAZ

Member

504-1

Member

Similar threads