P0306 Misfire Problems
#1
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P0306 Misfire Problems
Howdy everybody! This is my 1st post and I appreciate any help i can get.
I bought my sisters used 97 T100 v6 S/C with both heads blown.I got a pull out 96 t100 3.4L v6 motor from the local junkyard, and swapped it out leaving it normal aspirated. With motor in, vacuum lines matching the 97's diagram, I started it up. motor fired up 1st try but its missing. It throws P0306 (misfire on cylinder #6.) p0304 (cylinder 4) and p0300(random misfire) and runs really rough and the check engine light flashes. So i turned it off. I'm not having the truck adjust its fuel trims. Which i dont know if it would with misfires recorded. Just for fun i switched out this trucks ECU with my Soon to be race motors ecu and it still failed so i'm eliminated that option....so im left with more questions than answers..lol any ideas?
I have Replaced with new spark plugs
Swapped coil packs with wires
Check that i have spark at the plug
Swapped injector 1 to 2 ……3 to 4 … 5 to 6
Check coil ohms on injector 13 ohms (all 6 where 13ohms)
Check voltage from ECU that feeds # 6 injector 12vdc
Checked for any loose grounds
replaced fuel pressure regulator
Check compression 130psi on all 6 cylinders
Still misfiring on #6, #4 Any ideas before i pull the head and look for anything screwy with the valves? I know this is not a tacoma and this is a tacoma fourm, but the motors are pretty close to being the same.
Thanks in advance!
I bought my sisters used 97 T100 v6 S/C with both heads blown.I got a pull out 96 t100 3.4L v6 motor from the local junkyard, and swapped it out leaving it normal aspirated. With motor in, vacuum lines matching the 97's diagram, I started it up. motor fired up 1st try but its missing. It throws P0306 (misfire on cylinder #6.) p0304 (cylinder 4) and p0300(random misfire) and runs really rough and the check engine light flashes. So i turned it off. I'm not having the truck adjust its fuel trims. Which i dont know if it would with misfires recorded. Just for fun i switched out this trucks ECU with my Soon to be race motors ecu and it still failed so i'm eliminated that option....so im left with more questions than answers..lol any ideas?
I have Replaced with new spark plugs
Swapped coil packs with wires
Check that i have spark at the plug
Swapped injector 1 to 2 ……3 to 4 … 5 to 6
Check coil ohms on injector 13 ohms (all 6 where 13ohms)
Check voltage from ECU that feeds # 6 injector 12vdc
Checked for any loose grounds
replaced fuel pressure regulator
Check compression 130psi on all 6 cylinders
Still misfiring on #6, #4 Any ideas before i pull the head and look for anything screwy with the valves? I know this is not a tacoma and this is a tacoma fourm, but the motors are pretty close to being the same.
Thanks in advance!
#2
Me too!
Howdy everybody! This is my 1st post and I appreciate any help i can get.
I bought my sisters used 97 T100 v6 S/C with both heads blown.I got a pull out 96 t100 3.4L v6 motor from the local junkyard, and swapped it out leaving it normal aspirated. With motor in, vacuum lines matching the 97's diagram, I started it up. motor fired up 1st try but its missing. It throws P0306 (misfire on cylinder #6.) p0304 (cylinder 4) and p0300(random misfire) and runs really rough and the check engine light flashes. So i turned it off. I'm not having the truck adjust its fuel trims. Which i dont know if it would with misfires recorded. Just for fun i switched out this trucks ECU with my Soon to be race motors ecu and it still failed so i'm eliminated that option....so im left with more questions than answers..lol any ideas?
I have Replaced with new spark plugs
Swapped coil packs with wires
Check that i have spark at the plug
Swapped injector 1 to 2 ……3 to 4 … 5 to 6
Check coil ohms on injector 13 ohms (all 6 where 13ohms)
Check voltage from ECU that feeds # 6 injector 12vdc
Checked for any loose grounds
replaced fuel pressure regulator
Check compression 130psi on all 6 cylinders
Still misfiring on #6, #4 Any ideas before i pull the head and look for anything screwy with the valves? I know this is not a tacoma and this is a tacoma fourm, but the motors are pretty close to being the same.
Thanks in advance!
I bought my sisters used 97 T100 v6 S/C with both heads blown.I got a pull out 96 t100 3.4L v6 motor from the local junkyard, and swapped it out leaving it normal aspirated. With motor in, vacuum lines matching the 97's diagram, I started it up. motor fired up 1st try but its missing. It throws P0306 (misfire on cylinder #6.) p0304 (cylinder 4) and p0300(random misfire) and runs really rough and the check engine light flashes. So i turned it off. I'm not having the truck adjust its fuel trims. Which i dont know if it would with misfires recorded. Just for fun i switched out this trucks ECU with my Soon to be race motors ecu and it still failed so i'm eliminated that option....so im left with more questions than answers..lol any ideas?
I have Replaced with new spark plugs
Swapped coil packs with wires
Check that i have spark at the plug
Swapped injector 1 to 2 ……3 to 4 … 5 to 6
Check coil ohms on injector 13 ohms (all 6 where 13ohms)
Check voltage from ECU that feeds # 6 injector 12vdc
Checked for any loose grounds
replaced fuel pressure regulator
Check compression 130psi on all 6 cylinders
Still misfiring on #6, #4 Any ideas before i pull the head and look for anything screwy with the valves? I know this is not a tacoma and this is a tacoma fourm, but the motors are pretty close to being the same.
Thanks in advance!
#3
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I actually had the plug wirers reversed on cylinder 4 and 6. I had the wrong diagram the first time.
Last edited by jalsum; 01-23-2016 at 02:10 PM. Reason: Added photo
#5
Thanks for the reply
I appreciate the quick reply. But unfortunately that's not our problem. We double checked to be sure but the plug wires were correct. We have since replaced the injector connectors, replaced the wires from the ECU, checked splices in 12V source wires. And I have visually witnessed the injectors pulsing and the valves moving through the lower plenum. Compression 150, and good spark. Only other option is going to be swapping the crank position sensor and possibly the cam sensor. We even removed the O2 sensor to verify the cat wasn't plugged. I'm seriously scratching my head.......time to shotgun a few parts. It's cheaper than a dealer diag fee, which still may not tell us anything.
#6
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Verify crank pulley to 217lb/ft. Test crank sensor ohms (don't recall spec) although mine was bad and still tested fine. Ignitors and coils so rarely go bad. ECUs are rock solid as well. Verify you have all ground straps, battery to body, battery to block, rear passenger head to firewall.
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