I took a trip to the track yesterday. I was spraying most of the day and it was running pretty good. On my last run of the day it was making a loud sputtering noise and the power was cutting in and out on the top end. It starter to do this just before crossing the finish line. I immediately let out of it for fear that I had killed something. I have not ran it WOT since. Everything seems fine. I drove it about 1.5 hrs home. I'm about 90% sure it was probably just the nitrous running out. If it was anything serious I would not have made it home. I've never heard it sputter like that before though. In the past I just remember it losing power and reverting back to the normal WOT sound.

 

It sounds like your bottle was running out making it run pig rich. Remember when the bottle is half empty, it's really done. You will reach a point where you don't have the pressure and volume to make it work right. If it is running fine now on motor, I think you are ok.

Edit: one other thing it could be it's blowing the flame out on the spark plugs. I usually gap mine .032-.035 when spraying. Nitrous creates alot of cylinder pressure.

 

Sounds like the bottle was used up. How many runs did you have?

 

do you check bottle pressure? what was it at when you got home, or now, or when you can check?
Have you looked at the plugs at all?
Guessing pig rich. you probably at the very least, want to take a peak at the plugs.

is this a wet or dry system?
Shooting it in the MAF?

You could probably repeat it by closing the bottle valve and activating the system. Not that it would be good for your engine though.

 

Quick horsepower and can quickly fek up an engine if something goes wrong.

It does sound like it's running rich. Refill the bottle and do it again. If somethings going to break, it's going to break no matter if its at the strip or on the road.

Then again, if nitrous is used properly and you seem to know your stuff, maybe something was wrong and it just happened to break when using NOS.

Did you check the plugs yet???

 

Thanks for all the suggestions so far. I went WOT with no nitrous to 70mph this evening and it ran 100% fine.

A little more info...

I have been running the zex dry kit for a few years now. It introduces the nitrous after the MAF. The fuel and nitrous are controlled by the management unit. It also came with a fuel booster. The fuel control is regulated by the Zex management unit based on the current bottle pressure using the cars fuel presure regulator and injectors. I'm running 24# SVO injectors and PCMFORLESS tune. Unless the management unit went bad the fuel level should be fine. See link below better explanation on how the kit works.

I was spraying a 125 shot yesterday. I switch out the NGK plugs at least twice a year or more. I always gap them to .032. The car has never been filled with anything other than 93 octane. I run a nitrous tune and a NA tune for timing changes. This is the first time I've run the car with the new cam, valve train, timing chain, etc. but it ran great all morning.

I probably ran at least ten times maybe more. I could only spray half or two thirds the track with the street tires. I could not get enough traction. Unfortunately the new gauge I just received did not come with an electronic sender cable long enough to reach the pillar so I had to run all day without one. The old gauge I used to have right off the bottle broke recently. The nitrous and purge solenoids are original and a few years old. The management unit was replaced about a year ago.

After reading up on it some more this evening it seems a surging effect is normal when a nitrous bottle gets low, not sure about the zex kit. It's strange that I don't ever remember feeling this before. Maybe I just never had a bottle run out like that during a run or the managment unit is supposed to prevent this. What is the bottle supposed to weigh again, when full? I guess I need to pick up a second bottle to bring for next time. I didnt think of it at the time but I wonder if the track refills them. I'm going to call comp cams in the morning to see what they say about all this.

http://www.zex.com/Instructions/Files/ZEX130.pdf

 

I always carry a spare bottle (two actually) to the track... as a nitrous user, that kind of goes with the territory