Multiple misfire?
#21
I'm not doubting your methodology, just asking for a little clarification is all.
Truck got parked because of a flashing CEL and p1300, p0300, p0304, and p0308.
I purchase truck, put it new, good coils, plugs and wires. Make sure everything is right- this is my 3rd D2, and the 4th time I've done the job, so, while I clearly don't have as much experience as you, this isn't my first rodeo, and I do work on vehicles for a living, so I'm at least somewhat mechanically inclined lol.
After I i stall new parts, the codes become- p1300, p0300, p0303, p0304, p0306.
If I crossed wires or something, I's have at least 4 wonky cylinders, not 3. So while I am willing to do the work you described above, a modicum of detail and/or explaination would be very helpful. May help me, or others think of something else, or what have you. Thanks!
Truck got parked because of a flashing CEL and p1300, p0300, p0304, and p0308.
I purchase truck, put it new, good coils, plugs and wires. Make sure everything is right- this is my 3rd D2, and the 4th time I've done the job, so, while I clearly don't have as much experience as you, this isn't my first rodeo, and I do work on vehicles for a living, so I'm at least somewhat mechanically inclined lol.
After I i stall new parts, the codes become- p1300, p0300, p0303, p0304, p0306.
If I crossed wires or something, I's have at least 4 wonky cylinders, not 3. So while I am willing to do the work you described above, a modicum of detail and/or explaination would be very helpful. May help me, or others think of something else, or what have you. Thanks!
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Helias86 (02-24-2024)
#22
it is method known in industry as is/is not . As John So states we are comparing know good with suspected bad. It is misfiring on cyl3, is not on cyl5. So process of elimination to determine what are bad components. Many of us have had brand new components bad out of box. Most d2 misfire issues are ignition related. My recommended sequence is easiest to hardest in terms of time requirements.
Ooohhhh!!, ok!! Thanks so much! I'll give that a go then! I wasn't trying at all to aound ungrateful for advice, it just sounded a little overwhelming and a lot to try and process was all. I'll keep folks posted!
#23
Ok, long but productive day.
Switched junk around, and the misfires just continue to seem...random. i verified each cylinder is getting spark, the wires are indeed routed correctly, and the fuel injectors are for sure at least getting the signal to fire. Did a compression check and numbers were ok. Not great, but ok.
I did the compression test while the engine was cold, aince it's missing hard enough I don't wanna let it sit there and just idle and get warm..
I wedged the throttle open, and removed all spark plugs, and the lowest cylinder tested at about 135psi, the rest were 140-150psi when cold.
So.... I have 100% verified each cylinder has compression, is getting spark at the correct time, and that all 8 injectors are at least being told to squirt some petrol.
the engine starts up very very easily, so I feel inclined to rule out the crank sensor, but am curious about the camshaft position sensor, or the MAF, since either of those can c
ause such random and eratic misfires.
If anyone has any other ideas, I'm all ears!
Switched junk around, and the misfires just continue to seem...random. i verified each cylinder is getting spark, the wires are indeed routed correctly, and the fuel injectors are for sure at least getting the signal to fire. Did a compression check and numbers were ok. Not great, but ok.
I did the compression test while the engine was cold, aince it's missing hard enough I don't wanna let it sit there and just idle and get warm..
I wedged the throttle open, and removed all spark plugs, and the lowest cylinder tested at about 135psi, the rest were 140-150psi when cold.
So.... I have 100% verified each cylinder has compression, is getting spark at the correct time, and that all 8 injectors are at least being told to squirt some petrol.
the engine starts up very very easily, so I feel inclined to rule out the crank sensor, but am curious about the camshaft position sensor, or the MAF, since either of those can c
ause such random and eratic misfires.
If anyone has any other ideas, I'm all ears!
#24
I went through something similar chasing random misfires. I had “refreshed” my ignition system as well, got some Bosch spark plugs, NGK wires, etc. misfires started up shortly after. Chased that around like you did above. I ended up going with OE everything…Champion spark plugs, OEM wires (yes that hurt $), Bosch coil packs and OE O2 sensors.
By this time it was my third time removing the intake to get everything right….and I have been good ever since.
Not saying that you have the same issue, but you usually can’t go wrong using what the factory used.
By this time it was my third time removing the intake to get everything right….and I have been good ever since.
Not saying that you have the same issue, but you usually can’t go wrong using what the factory used.
#25
I went through something similar chasing random misfires. I had “refreshed” my ignition system as well, got some Bosch spark plugs, NGK wires, etc. misfires started up shortly after. Chased that around like you did above. I ended up going with OE everything…Champion spark plugs, OEM wires (yes that hurt $), Bosch coil packs and OE O2 sensors.
By this time it was my third time removing the intake to get everything right….and I have been good ever since.
Not saying that you have the same issue, but you usually can’t go wrong using what the factory used.
By this time it was my third time removing the intake to get everything right….and I have been good ever since.
Not saying that you have the same issue, but you usually can’t go wrong using what the factory used.
I hear ya. But at this point, I have verified each cylinder is getting fuel, spark, and has good compresaion. So this leads me to be rather certain it is something on the outaide of the engine, like the MAF or a cam position sensor, something like that.
#26
Sticking with the ignition, maybe check to ensure the coil grounds are solid. Could be a loose connection that works most of the time, or a wire that is partly cut.
Looks like there's been some electrical work done on the truck. Maybe check power to the coils as well for an intermittent voltage drop.
Then same logic for the injectors wiring.
Looks like there's been some electrical work done on the truck. Maybe check power to the coils as well for an intermittent voltage drop.
Then same logic for the injectors wiring.
#27
Sticking with the ignition, maybe check to ensure the coil grounds are solid. Could be a loose connection that works most of the time, or a wire that is partly cut.
Looks like there's been some electrical work done on the truck. Maybe check power to the coils as well for an intermittent voltage drop.
Then same logic for the injectors wiring.
Looks like there's been some electrical work done on the truck. Maybe check power to the coils as well for an intermittent voltage drop.
Then same logic for the injectors wiring.
I have verified each coil and each injector is working, so I am looking more towards the crank of MAF sensor at this point.
#28
OK. I suppose a bent or broken reluctor ring at the crank sensor could possibly cause misfires, but don't know how that would just show up one day. Maybe monitor timing advance with a scanner looking for sudden jumps. Is it different cold vs hot?
For the MAF, read real-time values with a scanner to rule that out. Same deal, looking for sudden unexpected changes.
For the MAF, read real-time values with a scanner to rule that out. Same deal, looking for sudden unexpected changes.
#29
OK. I suppose a bent or broken reluctor ring at the crank sensor could possibly cause misfires, but don't know how that would just show up one day. Maybe monitor timing advance with a scanner looking for sudden jumps. Is it different cold vs hot?
For the MAF, read real-time values with a scanner to rule that out. Same deal, looking for sudden unexpected changes.
For the MAF, read real-time values with a scanner to rule that out. Same deal, looking for sudden unexpected changes.
Today I'll be cleaning the MAF and checking the crank sensor after work.
#30
Update-
MAF got cleaned, crank sensor looked fine- wasn't loose or dirty looking, I know it may still be an issue, I just can-t quite get my hands in there right now. Tired and extremely frustrated.
throttle body got cleaned.
Checked plug wire routing again, all checks out.
Now I have misfire codes for 3,4,6,7 and a MAF low voltage code, after cleaning the dang thing. It was pretty dirty, jist find it funny that it wasn't throwing a code until after I cleaned it lol.
It is missing *hard*. Like I am starting to worry about breaking a piston at idle.
MAF got cleaned, crank sensor looked fine- wasn't loose or dirty looking, I know it may still be an issue, I just can-t quite get my hands in there right now. Tired and extremely frustrated.
throttle body got cleaned.
Checked plug wire routing again, all checks out.
Now I have misfire codes for 3,4,6,7 and a MAF low voltage code, after cleaning the dang thing. It was pretty dirty, jist find it funny that it wasn't throwing a code until after I cleaned it lol.
It is missing *hard*. Like I am starting to worry about breaking a piston at idle.