I've a supercharged 91 Z28, AFR heads, LPE blower cam, NX nitrous kit.

Here is my problem, I am hoping someone can help me out with this

I've had a NX kit with a 150 shot on my Z which activates via a hobbs switch. I also have a Harris Speed Works progressive controller set @ 20% and up to 100% in a 5 second duration. I have not driven my Z in 6mo. the other day, I decided to take it out and put some power down. I activated my system and I got a backfire I was very lucky! I pulled my foot out in the knick of time! Intake valve push rod was bent. I replaced it, lashed my valves and compression was 180 all across the board. No oil in my radiator either

Now, My Z runs fine without the NX system activated..perfect. BUT, If I activate my system with the bottle OFF. My Z backfires. I've 3 chips for my Z. Stock, a custom chip for my 30lb injectors, and my DIY chip. In the past, I could run my NX system with out the giggle gas and from the added fuel from the NX soleniod, I would notice a power gain, unless I was using my stock chip. Doing this wiht the stock chip would make it backfire = too rich. Ever since my backfire, my car sounds like a machine gun if I activate my NX system with the bottle OFF AND with the bottle ON!
I beleive my backfire last week was a result of something not being right with either the ignition system ( which checks out fine), or my fuel system...which I have questions about! How to tell if the injectors are leaking, how to tell if the fuel pressure regulator is bad.

Timing is the same 6 deg advanced.
plugs are gapped @ .35
fuel pressure is 45.
spryaed my intake with starter fluid while it was running and I found NO vacume leaks.

So, How do I check for a leaking injector? or a bad fuel pressure regulator?

I put my fuel pressure gauge on and with key on engine off, pressure was 40 and droped t zero after 20 minutes. I spoke with a FI shop and they said this was normal. the psi gauge while running was normal, around 45. looks as if it always has looked with a good fuel psi regulator. The shop told me to put a vacume to it and it should hold @ 20 inches of vacume. I've never done this before but my fuel psi reg. did now hold much. It got up to 15 inches of vacume while I was pumping it fast as I could in attempt to get it to 20. Then @ 15inches, when I got tired from pumping, the vacume would quickly fall off to zero. I don't think the regulator is bad because is holds consistant fuel pressure.

Any ideas:


an update;

I disconnected my progressive controller. I noticed something wierd on the display lights. After I removed the controller, I took my Z out for a spin. I first made sure my soleniods worked, activated the system withOUT the bottle turned on. My Z ran like a raped ape! so then I take her out and do a run with the bottle on. And it backfired. I quickly pulled my foot out of it, took her home and called it a night.

for some reason, removing my progressive controller seemed to help my problem. I have no idea why?

 

I had the same problem. Had a backfire with bottle,100 shot, and then anytime I tried to use bottle after that it was doing same thing you describe. I have since replaced that engine but have always wondered why it acted that way. Mine would run great unless I tried the bottle.

 

Man, I don't like the sound of that reply I'm going to try using a 75 shot tomorrow with a 50hp fuel jet. I really think she's running rich. If that works, I'll go up in hp in little stages

 

Turns out ALL 8 fuel injectors ohms read 0.01. I put my key on, then turned it off and within 15 seconds, my fuel psi dropped from 45 to 30. It took 2 minutes to drop to zero.

What would cause all 8 fuel injectors to go bad all at the same time?