Jeep Liberty misfires all cylinders

JWC

MEMBER
2003 JEEP LIBERTY
6 CYL
4WD
AUTOMATIC
86,000 MILES

I have 2003 Jeep Liberty and just had to replace the head gaskets. The week after I pick it up from the garage I get a Mil light, although engine ran fine. It was a misfire but seemed to be a one time accurance so it was reset. Two weeks later I start up the jeep get a flashing Mil light and the engine shuts off. I checked the codes and have misfires on each cylinder (3.7 V-6) and a oxygen sensor slow response. The engine will crank fine but not fire. I will go back to the shop on Tuesday but am looking for any help before then. Thanks for any advice.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

https://www.2carpros.com/articles/car-cranks-but-wont-start

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if okay-check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing

If both fuel and spark is present-check the valve and ignition timing, this will lead you to problems
with compression and valves opening and closing at the wrong time/broken or jumped timing
belt/chain.