Ram 1500 misfire

Bigjay73

Bigjay73

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Scan came up with:
P0174 system too lean
P0308 cylinder 8 misfire
P2323 ignition coil h secondary circuit.
Store computer recommends a new fuel pump, can anyone give an opinion with only these codes? Rough idle, CEL blinks if I floor it. New plugs, swapped the #8 coil with the #2 coil to see if the codes chased the coil to no avail.
 
Mine was cylinder 7 and it was in the CPU. Fried 3 coils fast before figuring that out… had to find schematic and hard wire it. I’m no mechanic but my BIL did this all for me.
 
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I was mistaken it was cylinder 7 when I bought it that was misfiring and we rebuilt the engine, it appears it was cylinder 6 that kept frying when we did this about a year after running fine.
 
Depending on the year, this is most likely a cam/lifter failure. You’re getting the slightly misleading ‘cylinder misfire’ code because at least one of the valves in that cylinder has drastically less lift than it did before. If it was just a misfire, the problem would follow the coil, or the plugs if you moved them too. Flattening the cam is a common problem in the Hemis, I’m the middle of fixing it on my wife’s Challenger.
 
As stated above, camshaft and valvetrain issues are common. Especially when you have a lean condition and just one cylinder misfiring (and bank two valvetrain failures are more common than bank one). Coil wiring is also a fairly common issue. You'll need to clear codes between diag steps as the pcm will shut off that injector when it flags a P2323. Start by checking for ignition on that cylinder. Another easy test is to use a vacuum gauge to monitor manifold vacuum. If the needle is bouncing at idle, it's likely a cam or lifter.
 
Last time I had a misfire, it was a scored cylinder and had low compression. Hopefully it's nothing serious. Simple would be the coil or plugs.

Check to see if there's resistance between the coil wires. There should be 2 terminals on the coil plug, put your multimeter in Ohms, touch one side to each side of the wire. If the circuit is open (OL) then the wire is broken, or there's a connection issue.
 
I had a similar problem with my Ford coyote motor. Not certain, but I would imagine problems might be similar. The #8 seems to be prone to going bad on motors. My problem was the cylinder/wall itself. (I don't remember the exact diagnosis) But it was throwing a misfire code, and had a shiny spot on the top of the cylinder. If the code isn't chasing the coil when you move it, I would lean towards it being an internal failure.

Good luck

That sucks.
 
mevertsen said:
I had a similar problem with my Ford coyote motor. Not certain, but I would imagine problems might be similar. The #8 seems to be prone to going bad on motors. My problem was the cylinder/wall itself. (I don't remember the exact diagnosis) But it was throwing a misfire code, and had a shiny spot on the top of the cylinder. If the code isn't chasing the coil when you move it, I would lean towards it being an internal failure.

Good luck

That sucks.
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Yeah, I'm kinda leaning towards seeing what I can get for it as is as a trade in. 10 years old, it's been a good run
 
If you end up replacing the motor, Jasper makes an MDS-deleted motor that I believe takes out a lot of the cam and lifter issues. I had one installed in my truck a couple years ago and still get 19-20 mpg on stock-sized 10-ply tires.
 
Bigjay73 said:
Friggin marmot or squirrel chewed some wires. Can't complain, I really thought this was it for the ole girl
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Best outcome you could hope for! We’ve done three camshaft jobs on Mopar products this week (diagnosed over several weeks and finally got parts in one lump sum).
 
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