Is anyone else experiencing "cylinder 7 misfire detected?"

30

Asked by Jul 15, 2009 at 09:43 PM about the 2004 GMC Yukon SLT 4WD

Question type: Maintenance & Repair

After going through the normal checks - plugs, wires, coil packs - a new fuel injector in no. 7 cleared the code.  That was in May.  It is now July and the problem has returned.  Same cylinder, same problem.  Upon further inspection of the injectors, I found they are comtaminated with what looks like rust.  Ironically, there are a couple of Technical Service Bullitins out that describe what I am seeing.  Unfortunately, the TSB's only contain summaries.  Does anyone have any details they can share on a fix for this?

Oh, and another thing.  There is no exrenal fuel filter on this truck.  I happen to own the GM service manual and it shows where it is and how to replace it, but it is not there.  In the description of the fuel system, it says there is a filter in the fuel sending unit assembly inside the tank and is non-servicable.

2 Answers

12,125

You obviously at this point know what the problem is ( Rust ) - I would guess the fuel line enters the fuel rail around #7 cylinder hence it getting plugged Just a guess there :) Pull the tank my friend - Depending on the mileage do a PUMP and Filter screen ( No Cash then the screen is replaceable ) - Flush the tank and all lines INCLUDING the injector rail and injector screens ( they clean pretty easily with carb cleaner ) Reassemble ... Good Luck

30

Thanks for the response. That's what I was afraid I'd need to do. probably a good idea to flush the entire system out. Can't imagine where the rust (if that's what it is) is coming from since most of the system is plastic. Thanks again.

Your Answer

GMC Yukon Experts

  • #1
    clayduster71
    Reputation
    2,540
  • #2
    David Boccabello
    Reputation
    780
  • #3
    Drpsychmom
    Reputation
    650
View All

Related Models For Sale

Used Chevrolet Tahoe
618 Great Deals out of 36,026 listings starting at $1,800
Used Cadillac Escalade
216 Great Deals out of 11,009 listings starting at $2,900
Used GMC Yukon XL
224 Great Deals out of 12,948 listings starting at $1,495
Used Chevrolet Suburban
273 Great Deals out of 20,215 listings starting at $1,195
Used GMC Sierra 1500
781 Great Deals out of 67,901 listings starting at $1,800
Used Ford Expedition
393 Great Deals out of 21,971 listings starting at $1,500
Used Chevrolet Silverado 1500
2,119 Great Deals out of 183,385 listings starting at $1,900
Used Ford F-150
2,216 Great Deals out of 180,841 listings starting at $1,500
Used Jeep Grand Cherokee
919 Great Deals out of 70,536 listings starting at $995
Used Ford Explorer
820 Great Deals out of 62,484 listings starting at $1,495
Used Dodge Durango
277 Great Deals out of 20,105 listings starting at $999
Used Toyota 4Runner
234 Great Deals out of 21,052 listings starting at $1,500
Used Nissan Armada
149 Great Deals out of 8,863 listings starting at $3,977
Used Toyota Sequoia
119 Great Deals out of 5,347 listings starting at $2,695

Used Cars For Sale

2017 GMC Yukon SLT 4WD For Sale
26 Great Deals out of 1,897 listings starting at $43,677
2016 GMC Yukon SLT 4WD For Sale
7 Great Deals out of 256 listings starting at $38,495
2015 GMC Yukon SLT 4WD For Sale
21 Great Deals out of 444 listings starting at $34,998
2014 GMC Yukon SLT 4WD For Sale
5 Great Deals out of 72 listings starting at $23,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.