99 tahoe missing badley when accelerating. popping code p 303

[Lucasswain]

So i need some advice my lifted tahoe is runing badley at accelerating and pulling hills. I was driving my nirmal rout to work and its a nice size hill it started missing bad shudering and check engine light came on and started blinking. After I got upp the hill its stoped blinking and about a day later check engine light turned off. But I read the code p 303 random missfire. Is this my spider injectors or what? I ri changed the cap plugs and wires last summer and it shouldnt be that. But please help im at a loss. Iv spent allot of time on this tahoe and im frustrated to say the least

 

[SunlitComet]

You will need to inspect your cap for burn or short marks inside the cap. More individual cylinder misfires happen with the vortec cap then with any other part. Ensure the spark plug is gapped at .060. The replacement plug should have been gapped at that already and unless it is a copper core standard plug do not attempt to re-gap it. Remove and measure the resistance of the spark plug wire as well. if it still eludes you you can have a injector balance test done to see how the injectors are putting out fuel. There is also a possibility that one of the two valves in the cylinder bay be binding a bit.

 

[Lucasswain]

Thank you verry much. It was missing a little bit last summer when I put new cap,plugs,and wires on it but beraly ever just a randum once in the while thing and it was usualy when I was on my way to work on a good size hill. But never like this it seems it has goten progresavly worse over the last month or two. Its bad enouph to wete I wont drive it to work because of that hill. I have spent allot if time and money on my tahoe and its like my baby. From 6" lift torims to big 35"tires new exhaust system cold air intake extended driveline because of lift and endless amount of time working on it. And now that its running badley it makes me ill. Ill pull the cap, wires and plugs tomarow and let you know. Thanks for the advice.

 

[SunlitComet]

One other thing even tho you specifically got a misfire code for cylinder #3 have your misfire history checked to look for any other anomalies that have not shown up as a specific cylinder fault.