#8 cyl miss

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Oct 8, 2012 | 08:26 AM

MYFORD250

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Joined: Dec 2003

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#8 cyl miss

hello all. i have a 2002 f550sd. 7.3, i have a engine miss, i did a cyl contrubution test, and it gave me cyls 1 and 8. so did the tested the connections at the under valve cover connector, and showed ok. plus i have no codes. i replaced both injectors, and started the truck it ran better, but still had a dead cyl. repeted the balabce test and still shows #8 not contributing. number 1 is fine now. i did a compression test on # 8 and it showed good, thought i might have got a bad rebuilt injector so i got another one and installed it. still have the same problem. the engine also seems like its loading up like a injector isnt closing. lots of blue smoke and raw fuel smell. is there a possibility that another injector could cause the contrabution test to falsley read?
any ideas?

Oct 8, 2012 | 09:24 AM

stinson 108-1

stinson 108-1

Joined: Jan 2012

Posts: 1,015

Likes: 8

From: south jersey

I'm not a mechanic, but I would stop replacing injectors for now. Research the cps threads, I think you'll find info on miss firing inj. like #8 or others from the cps. Guys with the real info will see this and steer you right. Also I believe 8 starves some for oil because of where it is in the firing order and its at the end of the oil rail.