#5 Clylinder misfire
atvchic
06-29-2009, 05:58 PM
blackened plug changed everything tune up related incl the distri. thinking injector runs like a bag of crap till you change to plug, this thing is driving me nuts any ideas or has anybody heard of this problem before....
rhandwor
06-29-2009, 06:27 PM
An injector can leak but I would check compression before buying a new injector. You also could use one heat range hotter plug if compression related.
Ohm your plug wire I've found new wires with poor crimp jobs.
Ohm your plug wire I've found new wires with poor crimp jobs.
atvchic
06-29-2009, 06:35 PM
I have already done a compression test and changed all the wires, plug cap rotor, distributor, coil,o2 sensors all delco parts of course everything is fine there... but misfiring at only one cly the plug keeps fowling up dry, black carbon and sometime black smoke comes from the exhaust, I even put motovac cleaner thru the fuel system and black flakes came out I have talked to the dealerships too and they have no idea why this is happening and neither does any of the techs at my shop where i work...
rhandwor
06-30-2009, 05:06 AM
I'm retired now but I had numerous cars come in that had new wires installed.
I had an oscilloscope and I could pinpoint which plug wasn't firing. A lot of times the customer had installed new plug wires. I checked the wire with an ohm meter and it was bad. Ninety five percent of the time it was a loose terminal on the plug end. I used a staple and re crimped the the connector I have a plug wire crimper. This fixed the problem and I charged shop time to fix the problem. They weren't happy with the wires but glad the vehicle run properly.
I've also found a cracked plug or one that was dropped with the wrong gap.
Remember these weren't Delco wires or good quality Napa.
I had an oscilloscope and I could pinpoint which plug wasn't firing. A lot of times the customer had installed new plug wires. I checked the wire with an ohm meter and it was bad. Ninety five percent of the time it was a loose terminal on the plug end. I used a staple and re crimped the the connector I have a plug wire crimper. This fixed the problem and I charged shop time to fix the problem. They weren't happy with the wires but glad the vehicle run properly.
I've also found a cracked plug or one that was dropped with the wrong gap.
Remember these weren't Delco wires or good quality Napa.
ken_man_1
07-14-2009, 08:43 AM
blackened plug changed everything tune up related incl the distri. thinking injector runs like a bag of crap till you change to plug, this thing is driving me nuts any ideas or has anybody heard of this problem before....
I had same problem - replaced the injector spider assembly and the truck ran with no problems right after that. There is a new updated spider available for this truck now that is 10 times better than the original. Hope this helps.
I had same problem - replaced the injector spider assembly and the truck ran with no problems right after that. There is a new updated spider available for this truck now that is 10 times better than the original. Hope this helps.
Automotive Network, Inc., Copyright ©2025