Melting #5 Plug with Nitrous????
 

I put a Zex nitrous kit in my stang last weekend. On monday I got the bottle filled and decided to make a test run on the way to work. It ran fine and the air/fuel was right between stoichiometric and rich. Afterwords, it was missing and running like ****. I pulled the plugs, and the number 5 electrode was melted over onto the center of the plug. Every other one looked perfect. I got a diffent plug, and tried that. It still ran like crap. Last night, I got a new injector for it, and did a cylinder pressure test. I also pulled the valve cover and checked the pushrods and rockers. The cylinder had about 140 psi pressure, and so did the rest, relatively. I put it all back together, and it ran great. No miss, hesitation, or popping.Today Idrove it withoutnitrouswith the timing at 17* and itran great. When I got home, Iset the timing to 4* and tried the nitrous again. Same thing- it burned the heck out of that one plug. I'm running a 150 shot on a wet kit. The heads are off a 69, and the autolite 25's are the coldest they go (1 range colder) without going to a plug with a shorter depth. Even with those plugs though, I still should see the problem with all cylinders if it was a timing issue.

Any ideas????

RE: Melting #5 Plug with Nitrous????
 

pop the dizzy cap off.
i bet the terminal for that wire is gone.

RE: Melting #5 Plug with Nitrous????
 

Nope- the terminal is still there. I'm about positive its getting spark, but for some reason its running way too lean.

RE: Melting #5 Plug with Nitrous????
 

Actually you can step down to an autolite 24, the 25 is stock.

RE: Melting #5 Plug with Nitrous????
 

yah i can see its running a tad lean, lol

well, 150 wet shot shouldn't do that, unless the "wet" aspect wasn't functioning properly. you need at least a 155lph pump to run that shot.

what you running?

RE: Melting #5 Plug with Nitrous????
 

The pump is stock. Zex never says anything about needing a bigger pump, but it would definately be a possibility. Any idea why it would only do it on one cylinder though?

RE: Melting #5 Plug with Nitrous????
 

Also, ditch that narrowband POS and get a wideband. All that it is going to tell you is if you're running 14.7:1 AFR, above or below that. No real numbers.

RE: Melting #5 Plug with Nitrous????
 

theres a few different reasons for that to happen to only one cylinder.

off the top of my head real quick, you could have a tad higher compression ratio in that cylinder caused by a bit of carbon buildup.
timing and lack of fuel will affect that cylinder before any other.

RE: Melting #5 Plug with Nitrous????
 

what if there was a vaccum leak on the lower intake for that runner?

RE: Melting #5 Plug with Nitrous????
 

yup that would do it too.
he would most likely be able to feel that though.