Random misfire help
11-19-2012, 08:13 PM
#11
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Truck runs fine. CEL shows random misfire. With a snap-on solus scanner the o2s look to be working fine. The only strange thing I see is in the pic below 99kpa It never moves from there either. I have swapped coils and wires and plugs at 2 and 4. because 2 was showing the misfire. The misfire moved over to cyl #1 and it just floats around. What say you guys on the subject? Map sensor? Sorry I did not get a better pic.
Do you feel a misfire or is it running fine??
Ryan
11-19-2012, 08:21 PM
#12
Then I have to find a shop or person to do it for me. I just do not have time and trust almost no one with my vehicles.
11-19-2012, 08:39 PM
#13
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2004 6.0 2500hd . You do not feel the misfire at all. I replaced the map sensor and it threw another code as if it was a gang sign. LOL I think it is going to need that tsb that does something with that thing around the gas tank and reruns a vent line to the intake. Something to do with emissions and not venting the gas fumes into the atmosphere. I can not remember the code. I have not done it yet and am not too worried about it. I am more worried about the door hinge that a body shop is replacing for me Monday. Then I have to find a shop or person to do it for me. I just do not have time and trust almost no one with my vehicles.
Then I have to find a shop or person to do it for me. I just do not have time and trust almost no one with my vehicles.I promise that will solve it. It you have ran it for any period of time like that flush the transmission.
A misfire prohibits converter lockup which causes higher trans fluid temps. Hard on fluid. Its cheap maintenance.
Do the variation relearn and post your results, im confident it will fix your problem.
good luck!
Ryan
Last edited by BetMinesFaster; 11-19-2012 at 09:04 PM.
11-20-2012, 01:28 AM
#15
2004 6.0 2500hd . You do not feel the misfire at all. I replaced the map sensor and it threw another code as if it was a gang sign. LOL I think it is going to need that tsb that does something with that thing around the gas tank and reruns a vent line to the intake. Something to do with emissions and not venting the gas fumes into the atmosphere. I can not remember the code. I have not done it yet and am not too worried about it. I am more worried about the door hinge that a body shop is replacing for me Monday. Then I have to find a shop or person to do it for me. I just do not have time and trust almost no one with my vehicles.
Then I have to find a shop or person to do it for me. I just do not have time and trust almost no one with my vehicles.
If your refeerning to TSB 02-06-04-037D for P0446 and routing the new canister vent valve above the transmission. That has nothing to do with a miss fire issue. If you swaped coils from 2 and 4 and the miss fire moved from 2 to 1 that shows you may have an issue with weak spark. When is the last time you did plugs and wires??? If its been a while do that first, then Preform a crank relearn.
I have no idea what your referring to under the 99KPA value that you were concerned with.
11-20-2012, 06:49 AM
#16
If your refeerning to TSB 02-06-04-037D for P0446 and routing the new canister vent valve above the transmission. That has nothing to do with a miss fire issue. If you swaped coils from 2 and 4 and the miss fire moved from 2 to 1 that shows you may have an issue with weak spark. When is the last time you did plugs and wires??? If its been a while do that first, then Preform a crank relearn.
I have no idea what your referring to under the 99KPA value that you were concerned with.
The plugs and wires are new. The 99kpa was associated with the map sensor. I will look at all of that this afternoon. p0446 was the other code it just recently threw. I sometimes hate being a cheap skate. I bought a truck with small issues because I had a mechanic on my staff. I no longer have a mechanic on staff and it sucks.
11-20-2012, 08:13 AM
#17
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If your refeerning to TSB 02-06-04-037D for P0446 and routing the new canister vent valve above the transmission. That has nothing to do with a miss fire issue. If you swaped coils from 2 and 4 and the miss fire moved from 2 to 1 that shows you may have an issue with weak spark. When is the last time you did plugs and wires??? If its been a while do that first, then Preform a crank relearn.
I have no idea what your referring to under the 99KPA value that you were concerned with.
With an unlearned CKP variation the misfire can float and change cylinders as well. Seen it happen numerous times.
You seldom see coils bad on these trucks. Very seldom.
I would not be concerned about PID data on a sensor that looks way out of wack unless there is a code for that sensor/system. If the MAP signal was way off it would have set a MIL and a code for that.
Ryan
11-21-2012, 09:28 AM
#19
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Glad that looks to have solved your problems.
That P0446 will not affect how it runs, but is worth fixing in case the MIL needed to be on for something more critical.
You can get un updated evap vent kit from Napa, the dealer, etc. But, its worth paying someone to diagnose it. If the code sets right away when you turn the key, its likely a circuit fault or something of that nature.
That kit costs more than a diagnostic does, so...its worth a diagnostic from a qualified tech. If you dont know of a good shop near you, I would go to a Chevy dealer, at least they are very familliar with the vehicle and its evap. system.
Ryan
That P0446 will not affect how it runs, but is worth fixing in case the MIL needed to be on for something more critical.
You can get un updated evap vent kit from Napa, the dealer, etc. But, its worth paying someone to diagnose it. If the code sets right away when you turn the key, its likely a circuit fault or something of that nature.
That kit costs more than a diagnostic does, so...its worth a diagnostic from a qualified tech. If you dont know of a good shop near you, I would go to a Chevy dealer, at least they are very familliar with the vehicle and its evap. system.
Ryan
11-21-2012, 09:34 AM
#20
Glad that looks to have solved your problems.
That P0446 will not affect how it runs, but is worth fixing in case the MIL needed to be on for something more critical.
You can get un updated evap vent kit from Napa, the dealer, etc. But, its worth paying someone to diagnose it. If the code sets right away when you turn the key, its likely a circuit fault or something of that nature.
That kit costs more than a diagnostic does, so...its worth a diagnostic from a qualified tech. If you dont know of a good shop near you, I would go to a Chevy dealer, at least they are very familliar with the vehicle and its evap. system.
Ryan
That P0446 will not affect how it runs, but is worth fixing in case the MIL needed to be on for something more critical.
You can get un updated evap vent kit from Napa, the dealer, etc. But, its worth paying someone to diagnose it. If the code sets right away when you turn the key, its likely a circuit fault or something of that nature.
That kit costs more than a diagnostic does, so...its worth a diagnostic from a qualified tech. If you dont know of a good shop near you, I would go to a Chevy dealer, at least they are very familliar with the vehicle and its evap. system.
Ryan