Misfire cylinder 4,5,6,8

[Roy Smith]

Hey all... Im new here and have read great information but nothing that specified. I have a 2006 EB Expedition 5.4 3v. New Intake gasket, plugs, coils. The injectors are operble and cleaned. I keep getting misfire for cylinders 4,5,6,8. BUT when i unplug the coils from 4,6, and 8 the engine bogs as if theyre definitley working. Same with injectors for those particular cylinders. Cylinder 5 gives no response from injector nor coil when unplugged. I get no response from the camshaft sensor on the front of the block when unplugged either. As well as the sensor in the valve cover which im assuming is what ive read as "vct". Any suggestions welcome.Thanks

 

[Hamfisted]

How many miles on it? Have the phasers ever been replaced ?

 

[Roy Smith]

190k. Im not sure i took it as a partial trade on a 91 Formula. My next step was to remove the valve covers but after much reading i wanted to make sure i wasn't missing something simple.

 

[Hamfisted]

Well, I wouldn't be surprised if it wasn't time for the whole timing set, phasers, oil pump replacement job.... also inspect the camshaft lobes and rockers. When you get done with that, run at least 10w-30 synthetic oil rather than that 5w-20 junk.

 

[Roy Smith]

ok thanks ill look into this.

 

[Roy Smith]

update: Before i tore into everything i decided to buy a set of NOID lights and check the injectors this way instead of the old test light tool. Turns out the injector for cylinder 4 and 5 are not producing any power. Every other injector lights up and pulses. Guess ill dig around the harness. Truck does crank and run. Just horribly. Thanks

 

[Hamfisted]

That sounds reasonable. You can get a set of injector pigtails pretty cheap off Amazon. I think the heat off the heads just gets to 'em after many years. Look at your pigtail plugs and make sure of the connector pattern before you order.

 

[Roy Smith]

1st off thanks for responding.

I just checked the injector ground wire for cylinder 4 and cylinder 5 from directly out of the pcm. Still no power so im thinking the pcm itself is not sending the ground pulse. So power isnt going out at all to those particular cylinders. I would like to think that theres no way the pcm went bad on just those 2cyl but ive seen sillier outcomes. Im gonna go ahead and replace it seeing as all of the fuses checked out good and i doubt the crank sensor would be so exact as well.

 

[Roy Smith]

UPDATE: PCM fixed my issue. Had to get old key programmed and she fired right up with no missing or sputtering.

 

[pastorjeep]

So glad you got it fixed! I just did the valve body rebuild on a 05 I bought last Monday and went to test drive and it is missing so bad that it wouldn't barely move under it's own power! No check engine light so I need to start trying to find what cylinder is missing. Smells like raw gas out the pipe and the vehicle just bucks and shutters when you try to give it the gas in gear. In neutral it will rev fine with a miss only at idle.I had it towed to my house because of the tranny issue so did not know about the bad misfire until I tried to drive it today.