Please help...misfire cylinder 3
#1
Please help...misfire cylinder 3
Hello.... Been working on car for a while , Have changed pretty much everything i can throw at it. Car is 03 monte carlo ss 3800 V6.(250k) mileage
new parts include ......Coil packs, plugs, wires, LIM&UIM gaskets, Fuel filter & fuel pressure regulator , ICM tested good , swapped injectors around to see if trouble code would follow. Ran seafoam and 93 octane fuel .Still have cylinder #3misfire. Any ideas or help ??? What should normal compression be and fuel pressure ? Thanks !!!
new parts include ......Coil packs, plugs, wires, LIM&UIM gaskets, Fuel filter & fuel pressure regulator , ICM tested good , swapped injectors around to see if trouble code would follow. Ran seafoam and 93 octane fuel .Still have cylinder #3misfire. Any ideas or help ??? What should normal compression be and fuel pressure ? Thanks !!!
#2
Key on pressure should be around 45 psi and running with vacuum removed around 55 psi . As for compression you should be under 120 psi or the cylinder is probably dead and I have seen posting's between 130 psi and 150 psi but you can easily compare to cylinders 1 and 5 since there right there. Should check when power to ignition is disconnected and throttle plate wide open. These numbers might not be exact but should be close enough for testing 1/4 million mile engine.
Last edited by Jeffs02rwdSS; 02-28-2018 at 04:08 PM.
#5
Update :: Did compression test 180psi across all cylinders. Swapped injectors around again and GOT random misfire instead of #3 misfire. So got all NEW injectors. Now it is back to Cylinder 3 misfire!! Im baffled...Any help???? Thanks
#7
I mean, it's possible for random crap to happen if the MAF is bad. But have you checked all of the wiring to the injectors?
#9
Injector pulse was tested with noid light, allready done that one a while back...will double check them. ICM was load tested at Autozone or Advance dnt remember. Been throwing money at this girl getting old. Could it be a computer issue? ECU/ECM. It runs good doesnt seem be missing any power ...but can hear a lil miss and still have cylinder 3 misfire on the scanner. Grrrrrr