Misfire - Not Coil or Plug (SOLVED) (2 Viewers)

[RootMeanSqr]

I'm getting code P0302 - Cylinder 2 Misfire. When this is happened in the past, I replaced coil pack and away I went. Not this time.
I've replaced the coil pack (new) and swapped spark plugs (looked decent). I've also swapped coil pack with other cylinders as well (in case new one was also bad). Code stays with Cylinder 2 even after clearing. I also verified spark while cranking with plug outside the cylinder. Plugs 2 & 4 were loose, I re-tightened all of them. I focused on Cylinder 2 - Passenger Front, closest to the power steering pump (just in case I got my numbers wrong, wouldn't be the first time).

Background. Last week I had Fuel Injectors serviced, so I was into the fuel system/fuel rails. I also replaced the valve cover seals & spark plug tube seals in the valve covers.

Any suggestions? Did I miss anything? Only last think I can think of would be the newly cleaned fuel injector could now be clogged from debris in the fuel system. Thx.

 

[JunkCrzr89]

Damaged connector on the fuel injector, blocked injector port in the intake manifold, etc are potential options, considering your recent service.

 

[RootMeanSqr]

Damaged connector on the fuel injector, blocked injector port in the intake manifold, etc are potential options, considering your recent service.

Thanks. I'll have to put my stethoscope to that injector to see if it's ticking like the others... That should hopefully rule out a damaged connector. I did give it a shot of DeoxIT.

 

[JunkCrzr89]

Thanks. I'll have to put my stethoscope to that injector to see if it's ticking like the others... That should hopefully rule out a damaged connector. I did give it a shot of DeoxIT.

Did you replace the vibration insulators that fit in the injector ports on the intake manifold? Those have a tendency to break apart, which could clog the port.

 

[ttahara]

Swap injectors and see if the misfire follows.

 

[RootMeanSqr]

Solved! It was a stuck injector. Verified with stethoscope, no ticking. Tested resistance, barely out of spec (15 ohms), same as others. Would not cycle with pwr/gnd connections. Tapped it a few times with a box wrench, reversed polarity with the pwr/gnd and got it to cycle. Buttoned it back up, cranked it, smooth as butter again.

Thanks for the insights and quick responses! Let's hope it stays healthy and doesn't stick on me again.

 

[RootMeanSqr]

Swap injectors and see if the misfire follows.

Thankfully I didn't need to. Wasn't looking forward to pulling the fuel rail off again, although passenger side is not as bad.

 

[RootMeanSqr]

Did you replace the vibration insulators that fit in the injector ports on the intake manifold? Those have a tendency to break apart, which could clog the port.

Yes, all replaceable parts were replaced at the time of service. I agree, the ones I took out were crumbling, but I'm thinking it's okay since I got it running again. Thanks!

 

[JunkCrzr89]

Solved! It was a stuck injector. Verified with stethoscope, no ticking. Tested resistance, barely out of spec (15 ohms), same as others. Would not cycle with pwr/gnd connections. Tapped it a few times with a box wrench, reversed polarity with the pwr/gnd and got it to cycle. Buttoned it back up, cranked it, smooth as butter again.

Thanks for the insights and quick responses! Let's hope it stays healthy and doesn't stick on me again.

Yes, all replaceable parts were replaced at the time of service. I agree, the ones I took out were crumbling, but I'm thinking it's okay since I got it running again. Thanks!

Glad you got it fixed!