I replaced the spark plugs on my car today, and the plugs from cylinders 2 and 3 appear to have gone lean / overheated. All the others looked fine and they have done around 15,000 miles with lots & lots of nitrous hits. I am running 100 hp Compucar nitrous on a 305 TPI. Should I reduce the shot? Why is it only cyls 2 & 3 being affected? The plugs looked like the right hand picture below, but nowhere near as bad. The white insulator has a small chunk missing from cyl 2, the electrode appears to have melted very very slightly at the end.



Thanks for any advice.

 

im not really up to date with all this fuel injection stuff but my guess maybe just maybe the injectors for those 2 cylenders r on there way out. just a thought becuz u said that those 2 cylenders were goin lean maybe the injectors r dyin and thats y ur not gettin the right amount of fuel to them. im just guessin i dont know much about fuel injection....i luv carbs

 

you running a wet kit? where's the nozzle positioned.. it sounds like it's not distributing the juice evenly, or as the other guy said, you're injectors on those cylinders are dying. until you get it resolved, don't even think about spraying unless you want to be picking piston and rod pieces out of your oil pan.

You also may want to check the entire fuel system.. pump, all injectors, etc..

Are the injectors stock?

Do you have an a/f meter in the car now ? (the o2 sensor based ones are crap, but better than nothing..)

Strap that bad boy on a dyno with a wide band o2, and check it..don't spray until it's fixed, or you WILL be regretting it.