TLSF150
Junior Member
New guy here in need of serious help...
first off, the truck is a 2006 1500 5.7 Hemi with 125k miles.
I bought the 3 days ago it was running extremely rough, but I'm a pretty decent mechanic, at least I thought I was lol, so I offered the guy $1000 and after some negotiating (me not coming off $1000) he took it and i drove the truck home
the only codes that show up is a p0300 random misfire cylinders 1 2 3 and 4 all seem to be completely dead with misfire counts at 500 in the minute or so I was pulling live data, cylinder 5 is hit or miss with over 200 misfires 6 7 and 8 seem to be the only live cylinders but still had 1-5 misfires between them.
What I've done so far, replaced all 8 coil packs, all 16 plugs, no change, so I moved to fuel. pulled the injectors and really nasty brown fuel came out of the driver side rail, I went to pull a part and got 8 injectors out of an untouched 5.7 that was rear ended.. I also cut one of the injector pig tails so that I could make a diy injector cleaner... cleaned and tested all 8 injectors using a valve stem and battery they all worked perfectly. cleaned both rails out, installed injectors and again no change...
used my scanner to actuate the injectors with engine off and could hear all 8 activate...
pulled both valve covers and verified all valves were opening/closing, everything seems to be working and moving correctly...
so, I did a compression test all cylinders were 180-195.
fuel pressure is about 58 key on engine off, bounces between 60-65 very quickly while idling, it evens out at 65 at 1500 RPMs
as it sits now I've pulled the intake and again verified valves are opening and closing as they should, I'm going to replace the intake gaskets before re installing but I don't have high hopes of it fixing anything
I'm at a loss here, never have I encountered a truck that I couldn't diagnose or fix... there's no other codes, no O2 codes, no lean or rich, no cam or crank position sensor codes, nothing to go off except this p0300 that's kicking my butt
first off, the truck is a 2006 1500 5.7 Hemi with 125k miles.
I bought the 3 days ago it was running extremely rough, but I'm a pretty decent mechanic, at least I thought I was lol, so I offered the guy $1000 and after some negotiating (me not coming off $1000) he took it and i drove the truck home
the only codes that show up is a p0300 random misfire cylinders 1 2 3 and 4 all seem to be completely dead with misfire counts at 500 in the minute or so I was pulling live data, cylinder 5 is hit or miss with over 200 misfires 6 7 and 8 seem to be the only live cylinders but still had 1-5 misfires between them.
What I've done so far, replaced all 8 coil packs, all 16 plugs, no change, so I moved to fuel. pulled the injectors and really nasty brown fuel came out of the driver side rail, I went to pull a part and got 8 injectors out of an untouched 5.7 that was rear ended.. I also cut one of the injector pig tails so that I could make a diy injector cleaner... cleaned and tested all 8 injectors using a valve stem and battery they all worked perfectly. cleaned both rails out, installed injectors and again no change...
used my scanner to actuate the injectors with engine off and could hear all 8 activate...
pulled both valve covers and verified all valves were opening/closing, everything seems to be working and moving correctly...
so, I did a compression test all cylinders were 180-195.
fuel pressure is about 58 key on engine off, bounces between 60-65 very quickly while idling, it evens out at 65 at 1500 RPMs
as it sits now I've pulled the intake and again verified valves are opening and closing as they should, I'm going to replace the intake gaskets before re installing but I don't have high hopes of it fixing anything
I'm at a loss here, never have I encountered a truck that I couldn't diagnose or fix... there's no other codes, no O2 codes, no lean or rich, no cam or crank position sensor codes, nothing to go off except this p0300 that's kicking my butt
