Zex kit irregular

[Wicked98Six]

OK, I've been through about 30 lbs of nitrous, and this just happened. I was racing a turbo RX7 one night and I pushed it pretty hard. After the race, I noticed that when I hit the nitrous, the rpms would stutter and go up 100 rpm, then go down, then go up, etc for about 4 seconds, and then it would climb. We took the nozzle out and checked the spray pattern and it turns out when you hit the nitrous the spray pattern coming out changes shape from a circular pattern to a straight hose-like shape and then back. The spray would then stabalize after about 4 seconds. It would do this every time you activated the nitrous, whether or not it was purged first or just activated or not activated for a while. It would always do it when it was first activated. It's a zex nitrous system running a 75 shot. No filter or anything, just the basic dry kit with the purge. I have no ideas on what it could be

Second question is, how high of a shot can I go without overloading my stock fuel system? Would a 100 shot be too high? I have a MSD inline fuel pump but I haven't installed it yet. Thanks for the help

[12secondv6]

Well before you think about raising the shot you need to address your first problem.
You might want to check the plugs.
Also nitrous filter? Ever clean or check it?
Also how close/ far is it to the mass air temp?

I really am not familiar with zex but nitrous is nitrous

I juiced at a 120 shot with a modified computer, kenne bell boost a pump, and afpr.
If you mean bone stock unaltered fuel system then 75-85 max

[Wicked98Six]

There is no filter to clean or check. The engine pulls strong and idles perfect so I assumed the plugs are ok, I haven't had the time to check them. The nitrous nozzle is in my whisper lid, so its about as far from the maf as possible. What is an afpr? And I know raising the shot would be not recommended until the problems are worked out. Maybe I'll install that fuel pump. Is it possible it was the tank mounting? When it was first installed my friend put the tank in backwards, so all I got was vapor. When I put it in this time it is possible the pick-up tube wasn't in the very back corner for maximum nitrous scavenging, but it would have been very close. Would that do it?

[camar0guy]

<blockquote>quote:</font><hr>Originally posted by Wicked98Six:
There is no filter to clean or check. The engine pulls strong and idles perfect so I assumed the plugs are ok, I haven't had the time to check them. The nitrous nozzle is in my whisper lid, so its about as far from the maf as possible. What is an afpr? And I know raising the shot would be not recommended until the problems are worked out. Maybe I'll install that fuel pump. Is it possible it was the tank mounting? When it was first installed my friend put the tank in backwards, so all I got was vapor. When I put it in this time it is possible the pick-up tube wasn't in the very back corner for maximum nitrous scavenging, but it would have been very close. Would that do it?<hr></blockquote>

This may help, sometimes the stream changes due to the way the airflow flows into that area, i also have a zex kit on my 94 camaro, i run 55 shot and have no problems. I have noticed that sometimes the stream changes based on the way the air is sucked thru the intake.