Have changed all plugs and coil packs but still giting miss in 1 3 5 cil think its a short in wire hornins but cant find a diagram
If you are getting a misfire code on those three cylinders (all on just that one bank of engine!), it's probably not an electrical short, but something else causing misfire. Misfire codes are set when the power output from that cylinder is less than expected: the pcm senses a crankshaft lag in power output and sets the code.
Typically, misfires are caused by weak or missing spark, or by fuel/air mixture problems, or by low cylinder compression. The fact that your misfires are all on one bank (side) of the engine sounds suspiciously like the fuel/air mixture might be wrong for that bank, or the cylinder compression is low on that bank.
You could use a spark tester just to check spark on 1, 3, & 5. Use a calibrated spark tester to compare both banks-all 6 cylinders. I think you will see equal spark at all cylinders. The only shorts would be in the spark plug wires. And not likely all 3 went bad at once, although you could check them, maybe swap a few around and see if the misfire follows the wire.
Start looking for air or vacuum leaks that only affect bank 1. Possibly an intake manifold leak, could also be an exhaust leak, something that affects the air/fuel mixture in the bank 1 cylinders. Also you could do a compression test of the cylinders to make sure bank 1 is good, same compression as in bank 2 (the other side of engine). Just some tips to help you out, good luck.
Feb 20, 2016 |
Cars & Trucks