Ok this may be quite long but I'll give ya all the details...84 camaro...Chevy 355 w/dartII's..all forged rotating assembly with a holley projection 900cfm injection unit...and yes I know 900cfm is a bit much but I didnt build it...Bought it that way..But here's the problem...The car has a NOS cheater system with 150shot...the guy said he used it once and it worked which was probly 5 years ago...we tried it this past weekend and at WOT in 3rd gear when the button is pushed the engine bogs and just about dies out....we checked the nitrous flow and it shoots out of the solenoid when the button is pushed so it is being delivered...the guage reads 900psi. on the fuel side the FP is 15psi...we lowered it to 12 and got the same affect..bogging and dying out...soo my question is too much fuel? Nitrous is getting to the spraybar..all filters clear..Does nitrous go bad? we're totally stumped...I've mailed holley/NOS techline but have yet to hear back and figured I'd try here...so any help/suggestions would be greatly appreciated...thanks

-Brian

 

sounds like you could be getting too much fuel, how did you find out nitrous was getting to the spray bar? check the jets and the nitrous filter (if there is one) take a screw driver and put it against your ear and put the other end to the sollenoid and have a friend operate it, make absolute positive the sollenoids open and close. since its at 900 psi the bottle must be pretty warm. the only other thing l can think of is the bottle position, make sure the label is facing upwards, and the bottle is completely open the bottle shouldn't be lying level either, it should have about 15 degrees of a raise at the valve end. wheres the guage at?

nitrous doesnt go bad that l know of....weigh the bottle to make sure theres enough for the siphon tube to pick up.

 

The nitrous definately sprays out of the solenoid, with the nitrous hose unhooked from the spraybar, system armed the push of the button brings a continuous blast of freezing nitrous out of the solenoid (no WOT switch) and the hose into the spraybar can be blown through very easily so I believe your right with the fuel issue, but I'm kinda weary turning the fuel down, we brought it down to 12psi but I'd hate to torch the motor by turning the fuel down although it has a 900cfm projection unit on it and gets a ton of fuel anyway, the pressure guage on the tank reads 900psi, no heater and no temp guage, and the label is up. All I know is 1st, 2nd or 3rd gear wide open hit the button and the motor craps out and you just about kiss the dash, let go and it comes back to life...frustrating.

 

If you're running the stock 150hp jetting (63/71) then your fuel pressure is too high. Try turning it down to 6psi.

 

Your best bet is calling tech, dont email them its a waste!!!!How old is the nitrous? I would empty it out if its old, and refill it!!!

 

Dont waste your money by emptying the tank, nitrous doesnt go bad.
There is definaelty too much fuel.....how much black smoke do you see coming from the back when you hit the button? im better a considerable amount.
Look at the number on the jet on the nitrous side and the jet for the fuel side.
the jets should be in the plate where you have already taken off the -3 line coming from the solinoid.
Im betting its either too big on the fuel side, or the is no jet at all, and your fuel pressure is WAY WAY too high.....NOS recomends 6 psi, however id personally would set it at apx. 7 1/2 psi
Post the jet sizes on here and plenty of people will let you know whats wrong.

 

I have this exact problem and can't figure it out. I have the zex kit on my TPI engine and your right about almost hitting the dash. I only have a 75hp setting on it. The zex kit controls the fuel side.

 

Yep it was getting way to much gas. Cut down on the jet size and now it works great. give it a try, sounds like your getting to much gas without the nitrous.