Help on misfire out of ideas
10-16-2018, 05:03 PM
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Help on misfire out of ideas
I have 09 Silverado 3500hd 6.0 vortec automatic 4x4 about 86000 miles I'm getting multi misfires I erase it then get misfire #5 I have done plugs, wires, coils and swapped them around still get mult misfire clear it then get mis Fire #5 have 60lbs fuel pressure I pulled injectors swapped #5 with #3 still get #5 mis Fire all injectors are putting out same amount of fuel o2 reading seem to be good today I sprayed whole can carb cleaner thru butterfly new code for map sensor figure that'* from spraying plenum it just runs rough at idal with no power flashing engine light truck did sit for 3 to 4 years but I put about 500 miles on it since I got it running that was a bad ignition and lost keys I did notice injectors weren't spraying per say but all had same amount of fuel in there containers when I tested them I cleaned maf sensor I need help I am out of ideas it doesn't smoke or backfire and there is no knocking or ticking when it'* running local mech said maybe broken valve spring just don't think it is for no noise when running any help or ideas greatly appreciated
10-17-2018, 01:14 AM
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Try swapping injectors between 5 and another and see if the problem moves with it or not.
10-17-2018, 05:55 AM
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I have 09 Silverado 3500hd 6.0 vortec automatic 4x4 about 86000 miles I'm getting multi misfires I erase it then get misfire #5 I have done plugs, wires, coils and swapped them around still get mult misfire clear it then get mis Fire #5 have 60lbs fuel pressure I pulled injectors swapped #5 with #3 still get #5 mis Fire all injectors are putting out same amount of fuel o2 reading seem to be good today I sprayed whole can carb cleaner thru butterfly new code for map sensor figure that'* from spraying plenum it just runs rough at idal with no power flashing engine light truck did sit for 3 to 4 years but I put about 500 miles on it since I got it running that was a bad ignition and lost keys I did notice injectors weren't spraying per say but all had same amount of fuel in there containers when I tested them I cleaned maf sensor I need help I am out of ideas it doesn't smoke or backfire and there is no knocking or ticking when it'* running local mech said maybe broken valve spring just don't think it is for no noise when running any help or ideas greatly appreciated
10-18-2018, 12:47 AM
#4
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True Car Nut
To be fair, "everything possible" hasn't been done yet. We can help you get there though, but you have to answer more questions.
We're still looking for answers to my question of 09-09-2018 09:57MDT and 09-10-2018, 05:57MDT where I asked:
. . . and . . .
. . . to keep thread sprawl under control. We are also awaiting a response on the question:
. . . as it appears you either have two similar trucks with the similar issues or posted the same issue in two threads.
Either way, in order to eliminate confusion, we need to keep Jroy'* issue in Jroy'* thread and your issue in your thread, preferably: https://www.gmforum.com/gmc-chevrole...2500hd-312060/
If you have suggestions for troubleshooting his issue we're happy to have the assistance, however, his issue and driveline are different enough compared to your issue and driveline that likely the solutions will be different. You can always keep tabs on Jroy'* thread just in case, and if Jroy'* solution looks like it will help you, I'll probably remember to relay to: https://www.gmforum.com/gmc-chevrole...2500hd-312060/
Thanks!
10-19-2018, 03:14 PM
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i did swap #3 and #5 injectors and got no change I checked all injectors wires with noid tester and got all good results gonna do compression test today will give results when I can anymore idea or suggestions is greatly appreciated
10-19-2018, 10:34 PM
#6
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True Car Nut
Yeah, that'd be a good check. Has the engine had any trauma in its life that you know of?
10-21-2018, 12:21 PM
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No trama I know of besides sitting for about 3 yrs I did compression test twice on all cylinders plus put oil in #5 after getting 0 both times
compression results
#1 168
#3 165
#5 0. With oil in cylinder still 0
#7 165
#2. 165
#4. 160
#6. 168
#8. 165
pulled valve cover on odd side valves are moving and rockers are not any looser than the others I snaked a camera in thru the spark plug hole looked at the piston no hole and watched it go up and down the cylinder as I turned the crank by hand no scratches or gouging on cylinder wall and the oil I put in the cylinder is still sitting on top of the piston I did notice what looked like a stain on one part of the wall but nothing else also looked at valves with camera and they are closing and opening inside the cylinder I am totally at a loss on why no compression next step I'm thinking of putting more oil in cylinder to cover top of piston to see if it leaks by or I can get any type of compression on #5 any thoughts or ideas will greatly appreciated
compression results
#1 168
#3 165
#5 0. With oil in cylinder still 0
#7 165
#2. 165
#4. 160
#6. 168
#8. 165
pulled valve cover on odd side valves are moving and rockers are not any looser than the others I snaked a camera in thru the spark plug hole looked at the piston no hole and watched it go up and down the cylinder as I turned the crank by hand no scratches or gouging on cylinder wall and the oil I put in the cylinder is still sitting on top of the piston I did notice what looked like a stain on one part of the wall but nothing else also looked at valves with camera and they are closing and opening inside the cylinder I am totally at a loss on why no compression next step I'm thinking of putting more oil in cylinder to cover top of piston to see if it leaks by or I can get any type of compression on #5 any thoughts or ideas will greatly appreciated
10-21-2018, 01:28 PM
#8
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Broken valve face. Cracked head. Piston rings gone.
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10-23-2018, 06:12 PM
#10
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True Car Nut
Yeah, what they said ^^^^^^ .
A five year old C3500 being suddenly parked at less than 200,000 miles is unlikely. That'* a lot of investment to be left depreciating. Any idea why was it parked for so long?
Is it a construction/contractor/service truck or a personal truck?
A five year old C3500 being suddenly parked at less than 200,000 miles is unlikely. That'* a lot of investment to be left depreciating. Any idea why was it parked for so long?
Is it a construction/contractor/service truck or a personal truck?