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08-28-2012, 02:37 PM
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#1 |
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Registered User
Join Date: Jun 2012
Location: charlotte, north carolina
Posts: 950
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2004 duramax rough idle?
I have a 2004 gmc duramax and when its at idle it seems to surge? anybody had this problem or no how to fix it?
__________________
1969 chevy camaro Z28 #matchin Factory 4wheel disc 1969 chevy cst10 big block overdrive 5/7 drop dog dishs 1997 gmc yukon 2 door 2 wheel drive project 4/5.5 22s 2004 gmc sierra dually 4/4 lowering daily driver |
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08-28-2012, 08:46 PM
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#2 |
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Senior Member
Join Date: May 2009
Location: Fort Worth, TX
Posts: 6,370
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Re: 2004 duramax rough idle?
2 different Duramax engines were offered that year.....
LB7....8th digit 1 LLY....8th digit 2 So whats the 8th digit in the VIN? |
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08-28-2012, 08:47 PM
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#3 |
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Registered User
Join Date: Jun 2012
Location: charlotte, north carolina
Posts: 950
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Re: 2004 duramax rough idle?
It's a lly
Posted via Mobile Device
__________________
1969 chevy camaro Z28 #matchin Factory 4wheel disc 1969 chevy cst10 big block overdrive 5/7 drop dog dishs 1997 gmc yukon 2 door 2 wheel drive project 4/5.5 22s 2004 gmc sierra dually 4/4 lowering daily driver |
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08-28-2012, 10:04 PM
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#4 |
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Senior Member
Join Date: May 2009
Location: Fort Worth, TX
Posts: 6,370
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Re: 2004 duramax rough idle?
If you dont have a scan tool....Have someone check....
1. Fuel Rail Pressure (FRP) sensor & connector. Verify that actual vs desired fuel pressure match in scan data at low speed and under load and high speed. Wiggle the FRP sensor connector while the truck is idling, check for RPM change, Replace the FRP sensor and pigtail connector if RPM change is noted. 2. Graph the input pattern (desired) for the fuel pressure regulator. If the pattern has a saw-tooth appearance, replace the fuel pressure regulator. I replace the FRP sensor, Pigtail connector & Fuel Pressure Regulator. If I find ANY of the above. |
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08-30-2012, 04:57 PM
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#5 |
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Registered User
Join Date: Jul 2012
Location: hyrum utah
Posts: 45
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Re: 2004 duramax rough idle?
generally that's a good sign the fuel pressure regulators bad
__________________
'67 c10 lwb-"toothpaste fresh" '05 3500 dmax/alli ext.cb lwb 4X4 |
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08-30-2012, 11:13 PM
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#6 |
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Registered User
Join Date: Aug 2010
Location: AZ
Posts: 3,069
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Re: 2004 duramax rough idle?
My brother in law's 04 (LLY) does this same thing..... surging at idle. I will pass this info along to him as well.
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