Intermittent miss

Tiny
FLKELLEY
  • MEMBER
  • FORD F-150
2000 Ford e 150 conversion van. 4.6 triton, 120,000 mi. I recently purchased this van that appears to have been well maintained. It ran great until I washed the engine. Then I learned you don't wash the Tritons because of spark plugs mounted like early hemi's! It missed badly & didn't "dry out" The plugs were replaced-old ones look as tho they had been replaced not too long back. Started replacing coil boots, then one at a time the coils. After two and still a miss-not as bad- I had all 8 coils replaced, including the earlier 2. It now ran like it did when I bought it. 2000 miles later, now in TX. (1200 miles from home) it started missing one damp cool morning. At idle I can not feel miss. Put in gear at idle & I can feel it. When driving, miss is intermittent. Under hard throttle it does not seem to miss, but with soft throttle and moderate pull-like in overdrive at 50 on slight hill- it will miss.
I plan to replace the coils, 2 at a time using the new ones that I had replaced & see if that will fix. I Understand it is not easy on van, so would like your opinion before I start. MAP sensor? I read some of the articles in the faq & wondered if it would be easier to try that first. During routine maint I replaced the air filter before leaving on trip alto the old one was not very dirty.
Thanks, Frank
Friday, January 26th, 2007 AT 4:07 PM

4 Replies

Tiny
SERVICE WRITER
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Having the codes in the computer may help on this. It may indicate which cylinders are the troublemakers and shorten your testing time down. The Fords are common to have MAF and DPFE sensor problems.
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Saturday, January 27th, 2007 AT 8:34 AM
Tiny
SUSAN VALERIO
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I am wondering if this problem (coils failing) once they are replaced is common. I believe it may be worthy to replace the coils one time. My vehicle has 97,000 miles. But my concern is whether they will continue to fail after 2000 miles as the gentleman indicates in his original message.

Can you tell me the life expectancy of the coils?

The van gets excellent mileage and runs smoothly when this problem is not occurring. It is just starting to happen with frequency. Every time we are charged labor. We thought that replacing them all might save lavor. But if it is a problem that recurs, then I am wondering if I should report is and try to get Ford to stand behind it.

Thank you for your opinion.
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Tuesday, February 27th, 2007 AT 4:57 PM
Tiny
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IMHO, I doubt Ford really cares. We never found the result of his problem, so I wouldn't jump to a coil problem, or recurring problem. I would recomend starting a new post however.
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Tuesday, February 27th, 2007 AT 5:45 PM
Tiny
FLKELLEY
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After once again replacing all the plugs-some had a brown ring where the porcelin meets the metal (outside), with no improvement, they started replacing coils again. I had saved the two new ones the original repair shop put in when I furnished 8 new ones and had them install my new 8. The "reader" would not show a miss occuring altho we could feel it. Sure enough, the right rear (I don't know how ford numbers the cylinders) coil replacement cured the problem. I've driven it about 500 miles with no problem. However we leave for home tomorrow, so will see how long it lasts.
Flkelley
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Wednesday, February 28th, 2007 AT 12:12 AM

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