NEED HELP. Cyl 1 misfire & all circuits open

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Mikebigham32

Junior Member
Joined
Dec 24, 2021
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Location
Monroe NC
Ram Year
2008
Engine
Hemi 5.7
Hey guys I have an 08 ram 5.7 and about a year ago it randomly cut off driving down rd.. did it like 3x so ignored it.. then when I would fill it up completely it would cut off about a mile down rd so I just stopped filling it up completely.. then it started struggling to start it would take about 2 tries and it would fire up.. didn’t happen everytime but close enough. Took it to a mechanic and he couldn’t get it to duplicate.. we told him drive it then let it sit for 30 mins and it would happen.. he just said probably ECM needs replaced.. he said common issue.. so we found one on eBay.. installed didn’t fix problem.. then after a few months of driving it with these issues it started cutting off more while driving.. then check engine light came on said cylinder 1 misfire.. took it to another mechanic he said he could find anything maybe PCM needed replaced.. so we bought one.. didn’t fix. So we thought maybe it’s electrical.. took it to a shop that specializes in auto electrical issues... he could figure it out.. he traced wires and all.. said maybe new PCM was bad.. so got another one.. ended up getting 3 still didn’t fix. Now it says cylinder 1 misfire and all circuits open.. which is odd bc it still cranks and runs just rides rough/shakes and all at 40mph. At this point we have replaced injectors, coils, PCM, ECM, ignition switch... I’m wondering if I should replace injector wiring harness or the complete engine wiring harness.. ANY SUGGESTIONS or ANYONE had this issue or know someone who has? This is my sons truck he got it drove it for about a year and now it has sat since April. Only extra stuff he did to it was upgraded radio, added subwoofer-amp and installed train horn with air compressor .. THANKS
 
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Mikebigham32

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Dec 24, 2021
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Location
Monroe NC
Ram Year
2008
Engine
Hemi 5.7
The #1 cylinder injector is not pulsating but has power. Was yours like that?
 

MikeT

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Jan 28, 2017
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Location
Chino Valley, AZ
Ram Year
2006
Engine
CTD
How old is your battery, strange and not so wonderful things happen when batteries start to go south. At a minimum have a load test done on it.

Mike
 

BadHemi2014

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Feb 7, 2020
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Location
Greater Cincinnati area
Ram Year
2014
Engine
5.7 Hemi
Spark plugs? Compression test? Any tick or knock that might indicate a failed lifter? Just throwing ideas out there.
 
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Mikebigham32

Junior Member
Joined
Dec 24, 2021
Posts
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Location
Monroe NC
Ram Year
2008
Engine
Hemi 5.7
We did spark plugs, lifters, PCM, ECM. It’s definitely been a headache trying to figure it out. Motor is in great shape. I guess we will try intake gasket... we thought maybe fuel pump.
 
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