I installed my Zex Nitrous Kit (dry) a little over a month ago. I was too cheap to pay someone to do it, and too curious to not learn how to install, so I installed it myself. Over my break from school, took out the bottle and didn't play with it at all. Now that I'm back, I have the bottle back in and am encountering a little bit of a problem that I hope those with more knowledge about nitrous can help me out with.

I think I know what my problem is, but confirmation would be nice. Currently, the smallest jets are in (35hp shot). I'm not using any bottle warmers or anything that controls bottle pressure, and that's where I think my problem lies.

When running the nitrous, I always follow insturctions. I flip the switch after 2500 rpm, and the spray comes on at full throttle, and for about 10-15 secs it runs just fine. At some point though, my check engine light comes on and fuel supply is cut. So far, this has happened twice.

I think too much fuel is accumulating in the system b/c the nitrous isn't being supplied at the rate demanded by the solenoid due to low bottle pressure. The sensor reads that there's too much fuel entering the engine and cuts off supply to avoid an engine killing backfire. Does this sound at all right? I'm pretty noobish and somewhat ignorant at times, so any insight is appreciated.

My next purchase is a bottle warmer to hopefully help with this problem.

Also, found this on Zex's website, wish I wouldn't have tapped my intake, this thing is pretty cool. ZEX? - Sorry...

Thanks!

 

bump. someone can confirm that bottle pressure is the problem?

 

Best i could find: A ‘Dry’ nitrous system relies on the vehicle's computer system sensing that the engine is, say, running too lean and adding additional fuel. Most stock computer systems were not designed for this purpose, and may have difficulty in it. The internal-combustion engine is basically a large air pump and its ability to pump air is one of the factors, which determine how much power it can produce. Air contains oxygen and by drawing more oxygen into the combustion chamber, more power will be produced. In order to achieve efficient combustion, the air needs to be mixed with fuel in the correct ratio. The stoichiometric (chemically correct) ratio is for basic gasoline is 14.7 parts air to 1 part of fuel. Greater quantities of oxygen can be drawn into the combustion chamber by simply introducing nitrous oxide. By weight, Nitrous contains 36% oxygen while air has only 23%. A charge of nitrous oxide is capable of burning much more fuel than the equivalent amount of air. Because nitrous is more oxygen-rich than air, the recommended air fuel ratio becomes 9.5 parts of nitrous to 1 part of fuel (9.5:1). That means when oxygen-rich nitrous is introduced additional fuel must also be supplied in order to maintain the optimum ratioWithout the additional fuel the mixture would become dangerously lean - circumstances that will almost always lead to severe and expensive damage




Odds are you are running too lean not too rich. Get an OBD scanner and check for stored codes.

 

Wow, I just made a new post about my progress right about the time you replied... also I noticed in this thread I said I was running a dry kit. Well, I don't know what I was on, but it's not a dry kit, it's a wet kit. Yeah, and I've been meaning to take it to the parts store to have the codes checked. Thanks for answering. I've done quite a bit of research since my last post!

 

Looking back, you were spraying it all over the MAF and I'd bet that was the main problem. Ever gonna try again, or are you going to stick with selling it?

 

Yeah you're probably right. Still selling it, but not actively I guess. I'll still use it if I happen to still have it in a couple of years, lol.

 

How much quicker did it feel?

 

A lot. It jumped the tachometer up so quickly that it scared me. I ran a 45hp shot, which is good for ~30hp from what I understand.

 

It sounds like the big issue was what the last poster mentioned, you were merely getting the MAF hot wire wet. This screws up the MAF Raw Hz the ECU sees and everything goes all goofy after that! Maybe reinstall the fogger farther up stream and have at it again?

 

I use a cold air intake with a zex nozzle tapped into the K&N air filter. It works much better than tapping into the intake near the TB (spreads it out better)

Zex is a wet nitrous kit and the A/F ratio is controlled by your bottle pressure.

Also, no need to wait to switch it on...it will only spray at wot.

 

when you said it was a dry kit, and something about tapping the manifold, I was conserned.
a dry kit should be spraying before the MAS so the sensor can tell the fuel injection to spray more fuel


being a "wet" kit, you may want to put a smaller fuell pill in,
and tune using a wideband O2 sensor

when running a 125 hp wet shot, I used a 150 shot fuel jet to make up for the small "Lean spike" I was getting on the initial hit
I was also running a WOT switch, Digital window switch, fuel pressure safety switch (along with a bottle heater and remote opener)