1999 f250 missing
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1999 f250 missing
I have a 1999 ford f250 with a 6.8 liter v 10 engine. At about 40mph the truck will start missing and lacks power to accelerate further. This problem is intermittent. Some days it runs great and others the miss appears. Well I scanned and the code reader said that I had a misfire on cylinder 7. I took a chance and replaced the COP and the boot for that cylinder . Ran great for a day and then the miss came back. Same code again. What else might cause this? Are plugs difficult to change in these engines?
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Joined: Mar 2013
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From: Kent Station, WA
The plugs aren't real difficult to change. Definately use the motorcraft platinums, dielectric grease and take your time. Antisieze on the plugs is also a must.
Have you checked for any vacuum leaks or changed the pcv valve?
What brand COP did you replace with?
Has your fuel filter been changed and when?
Also check out the V10 forum down below a lot of good tech info and knowledge there
Have you checked for any vacuum leaks or changed the pcv valve?
What brand COP did you replace with?
Has your fuel filter been changed and when?
Also check out the V10 forum down below a lot of good tech info and knowledge there
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cop was made by bwd. The parts store guy said the Motorcraft was just as troublesome. I guess its possible I got another bad one. I will switch the coil onto another cylinder and see it misfires. No I have not changed the filter or the pcv valve. I will check those too.
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I had the same issue with my V10. This was even after new spark plugs. At 40 mph it felt like a gremlin was under the hood hitting the motor with a hammer.
So I pulled the COP's to have a look. I had the intention of replacing the boots and springs.. until I found this...
Cracks in the COP bodies. This was about 6 out of 10 of them.
Anyway.. 10 COP's later.. miss is gone!
My truck was a fleet truck but only had about 145k miles when I got it. I suspect it idled a LOT, not really sure why the bodies were cracked though.
Thanks!
Jeremiah
So I pulled the COP's to have a look. I had the intention of replacing the boots and springs.. until I found this...
Cracks in the COP bodies. This was about 6 out of 10 of them.
Anyway.. 10 COP's later.. miss is gone!
My truck was a fleet truck but only had about 145k miles when I got it. I suspect it idled a LOT, not really sure why the bodies were cracked though.
Thanks!
Jeremiah
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Today I switched the number 6 and 7 cop to see if it changed which cylinder was misfiring. While doing this I noticed that one of the inlets on the plastic airflow tube that runs from the throttle body to the air cleaner was creased pretty badly. I guess this was the result of someone over doing it on the the hose clamp. I manged to pry it back into to shape and reinforce it with some pipe. Started the truck drove around for about an hour and a half with no miss! Not sure if it was the cops or the air leak but I am glad its fixed.
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paulcalif
1999 - 2016 Super Duty
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Jul 18, 2010 10:09 PM
