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

11,945

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

Add photo

Related Questions

Search GMC Yukon Questions

GMC Yukon Experts

#1 clayduster71
clayduster71
Reputation 2,280
#2 David Boccabello
David Boccabello
Reputation 600
#3 Danielle Heller
Danielle Heller
Reputation 500
View All

Related Models For Sale

Used Chevrolet Tahoe
584 Great Deals out of 32,568 listings starting at $1,500
Used GMC Yukon XL
207 Great Deals out of 12,656 listings starting at $2,000
Used Cadillac Escalade
210 Great Deals out of 11,023 listings starting at $3,000
Used Chevrolet Suburban
262 Great Deals out of 19,840 listings starting at $1,800
Used GMC Sierra 1500
765 Great Deals out of 69,781 listings starting at $1,800
Used Ford Expedition
455 Great Deals out of 25,000 listings starting at $1,495
Used Chevrolet Silverado 1500
1,835 Great Deals out of 182,528 listings starting at $1,595
Used Ford F-150
2,068 Great Deals out of 208,304 listings starting at $290
Used Ford Explorer
993 Great Deals out of 70,217 listings starting at $997
Used Jeep Grand Cherokee
1,070 Great Deals out of 72,964 listings starting at $1,200
Used Dodge Durango
290 Great Deals out of 21,344 listings starting at $1,495
Used Nissan Armada
155 Great Deals out of 8,827 listings starting at $3,000
Used Toyota Sequoia
135 Great Deals out of 5,457 listings starting at $2,900
Used Toyota 4Runner
269 Great Deals out of 19,071 listings starting at $2,695

Used Cars For Sale

2017 GMC Yukon SLT 4WD For Sale
11 Great Deals out of 2,138 listings starting at $46,590
2016 GMC Yukon SLT 4WD For Sale
10 Great Deals out of 314 listings starting at $39,207
2015 GMC Yukon SLT 4WD For Sale
10 Great Deals out of 357 listings starting at $32,890
2014 GMC Yukon SLT 4WD For Sale
4 Great Deals out of 74 listings starting at $20,995

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.