Misfire cyl #3 HELP!!!!

[blownh2x]

I drove the vehicle last night - got on the gas - now I have a misfire. I noticed the misfire when I was parking the car and it was idling. I'm having the misfire on cyl #3 only (P303). I drove the car to a friends house nearby and changed some parts around. still has the misfire. Then I'm driving home and the vehicle is stumbling bad and decelerating, I press the gas and the car has no power, then all of a sudden it has power and lost power again. I barely made it into my garage from the lack of power. I changed some more parts around trying to move the problem to a different cylinder, but no luck. I have no cats, so only the pre-cat 02's. Did I maybe screw up an 02 sensor or not have enough fuel pressure?

I've checked everything below

1. coil pack - changed with cyl #1
2. spark plug - changed with cyl #1
3. Compression test - ok
4. Injector - changed with cyl #1
5. Plug wire - checked ohm reading and changed with cyl #1
6. Installed stock tune - no help / reinstalled custom tune
7. Cleaned MAF sensor

checking fuel pressure next and pulling valve cover off. any other ideas?

[shady milkman]

maybe the injector plug..clean off the plug and make sure it has slack

[shady milkman]

but yeah for sure take the vlave cover off and take a look.

[sunsetorangess]

Like said above, double check the injector harness and also the 02 harness.
J

[blownh2x]

maybe the injector plug..clean off the plug and make sure it has slack

I can hear the injector firing with a stethoscope, I did an ohm reading on it as well and checked it to another injector. I'm scratching my head on this one a little bit.

I smelled a real faint burning smell last night in the garage also now that I think of it - I'll check the 02 wiring. I remember zip tying it pretty good though - thanks for the help.

[shady milkman]

the way you discribe it though..sounds like it would be alot more then 1 cylinder misfiring...a possible fueling issue or i also hate to say it..did you check the main injectors plug..the white one with the blue locking thing ? when i removed my intake once i forgot to plug one side in...

[shady milkman]

opps never mind about the injector thing..you can hear it spraying

[blownh2x]

I can unplug inj#3 and vehicle stays the same because of the misfire on that cyl. If I unplug any other inj the vehicle idle changes so I know my prob is with #3 and I also had the P303 code. I don't hear anything going on in the valve train though - at least nothing rattling or out of the ordinary.

[shady milkman]

I can unplug inj#3 and vehicle stays the same because of the misfire on that cyl. If I unplug any other inj the vehicle idle changes so I know my prob is with #3 and I also had the P303 code. I don't hear anything going on in the valve train though - at least nothing rattling or out of the ordinary.

weird.

[blownh2x]

Will the valve covers come off pretty easy or is it a pain in the a$$

[Ryans99LS1]

They arent bad. Just take the coil rack off and then you just unbolt it.

[shady milkman]

Will the valve covers come off pretty easy or is it a pain in the a$$

very easy.

[Frost]

swap entire coil packs left to right and see if it moves. If it does, since you already looked at the coil the main coil harness connector is suspect. I have definitely had issues with that before.

[blownh2x]

swap entire coil packs left to right and see if it moves. If it does, since you already looked at the coil the main coil harness connector is suspect. I have definitely had issues with that before.

I did switch coil packs on cyl#1 to cyl#3 thinking the misfire would move to cyl#1 from cyl#3. I also checked for actual spark coming out the coil pack - it was good and strong. checking valve train when I get home after work and fuel pressure

[blownh2x]

OK, so I have a couple of bent push rods, a few rocker arms that are loose in the bearing department, and a electrical connector with some corrosion for the coil packs. I need to fix this problem and hopefully my problem above will go away. I'm thinking about going with 1.8 rocker arms and some chromemoly push rods, what do you think? Anything on sale you know of? I'm buying this weekend. Why are there different lengths of push rods? Is stock length 7.4"?

[Ryans99LS1]

stick with stock rockers.. Or if you wanna good stock upgrade use ls7's. not sure on stock length of the rods though.

[blownh2x]

stick with stock rockers.. Or if you wanna good stock upgrade use ls7's. not sure on stock length of the rods though.

I believe the LS7's have a taller installed height. I'll probably go with LS6 valve springs