Pikeman
New member
Ok here it goes. Last Friday I get a CEL with a PO304 code(missfire #4 cyl). Couple possibilites are Coil Pack or spark plug, Injector, clogged Cat or bad O2. I moved the coil packs and it stayed on the #4 cyl. Smell did not indicate clogged cat and it passed smog with no issues last year. So I bought an injector and put it in esterday on my lunch break.
Couple things not to do or are more preffered. It is not advisable to run on only 5 cyls. as you are super heating the missfiring cyl by it running lean. I did for a couple dys but only the 2 miles two and from work. Next most sources advise replacing all injectors at the same time. I decided to get one in case that wasnt the issue. Also not best to drive vehicle with a fuel leak. I said f-it it is only 2 miles and put my fire extinguisher on passenger seat and headed home. Then I drove it back to work this morning.
To replace the injectors you need to remove the intake plenum and then you will have full access to the fuel rails. 4 bolts, 2 nuts and a couple misc hoses and cables to remove the top half. Bottom is 8 bolts 2 nuts to remove the bottom half, this is including the small screws holding grounds and assorted brackets.
I was sailing along and had it back together in an hour, start it up and woo hoo the missfire is gone. Now for the bad news, I start gettng a fresh fuel smell. The #4 injector is under the plenum and could not see it even with an insection mirror. Time to take the intake off again. I tried three more times of cleaning the ports, lubing the o-rings and reassembling the fuel rail. the injector still leaks. (this is where I said f-it and drove it home). I have no clue why it isnt sealing properly but I know what I will be spending my lunch hour doing. Just wanted to vent a little, and if anyone had some advice to try what they suggest.
Couple things not to do or are more preffered. It is not advisable to run on only 5 cyls. as you are super heating the missfiring cyl by it running lean. I did for a couple dys but only the 2 miles two and from work. Next most sources advise replacing all injectors at the same time. I decided to get one in case that wasnt the issue. Also not best to drive vehicle with a fuel leak. I said f-it it is only 2 miles and put my fire extinguisher on passenger seat and headed home. Then I drove it back to work this morning.
To replace the injectors you need to remove the intake plenum and then you will have full access to the fuel rails. 4 bolts, 2 nuts and a couple misc hoses and cables to remove the top half. Bottom is 8 bolts 2 nuts to remove the bottom half, this is including the small screws holding grounds and assorted brackets.
I was sailing along and had it back together in an hour, start it up and woo hoo the missfire is gone. Now for the bad news, I start gettng a fresh fuel smell. The #4 injector is under the plenum and could not see it even with an insection mirror. Time to take the intake off again. I tried three more times of cleaning the ports, lubing the o-rings and reassembling the fuel rail. the injector still leaks. (this is where I said f-it and drove it home). I have no clue why it isnt sealing properly but I know what I will be spending my lunch hour doing. Just wanted to vent a little, and if anyone had some advice to try what they suggest.
