air fuel ratio gauge

poweredx2 · #1 06-13-2004, 06:51 PM

This is an old question that didn't get a answer,why would a a/f ratio gauge go blank using a 100 shot of nos an not a 50 or 75 shot or even on motor it don't go blank.I talked to a few mechanics said that maybe the zex kit bumps up the fuel pressure so high that it will not register,sounds like a possible answer.The car pulls like a train even after the gauge goes blank,comeon guys I am puzzled about this one.

mbtoloczko · #2 06-14-2004, 08:48 AM

When you say "blank", so you mean the indicator is pegged at either full rich or full lean?

AFBeefcake · #3 06-14-2004, 10:54 AM

No, he means the there are no LEDs lit up on the gauge. Mine does the same thing, but I don't have NOS.

IggDawg · #4 06-14-2004, 11:39 AM

if no LEDs are lit up, that means you're "off the scale" rich or lean. I'm guessing with a 100-shot you're off the scale on the rich end.

mbtoloczko · #5 06-14-2004, 12:00 PM

Quote:

Originally posted by IggDawg
if no LEDs are lit up, that means you're "off the scale" rich or lean. I'm guessing with a 100-shot you're off the scale on the rich end.

I'm wondering, is it even possible for the signal to go "off scale"? I had thought that narrowband O2 sensors produced a signal between 0 and 1 volt, and narrow band O2 sensor gauges just show that voltage.

IggDawg · #6 06-14-2004, 12:11 PM

I'm not sure how they work exactly, but I know I've seen it go so far to rich or lean that the last LED is so dim it's barely visible. I can imagine in extreme conditions that the sensor could behave strangely. any idea if it "pegs out" at one volt and holds that signal, or if it just stops signaling altogether?

AFBeefcake · #7 06-14-2004, 12:14 PM

If I had a O scope I could see if there was a signal, but I don't have one. sorry

svxfiles · #8 06-14-2004, 08:31 PM

What kind of A/F gauge do you have? My Nordskog digital A/F cycles, from blank, up to 2 amber bars into the rich side. A picture is worth a thousand words.
zipped video file of a/f gauge

OK, that took 41 days. But onto the (potential)problem, As I understand it, nitrous oxide has 2 oxygen molecules, for every 1 oxygen molecule, What that does is provide more oxygen into the mix, if this is an AIR/FUEL mixture, then the mix is leaner! So with a 100 hp shot, the mix is leaner than with a 50 or 75 hp shot. Unless you are suppling more fuel, the engine will run lean. Tom.

poweredx2 · #9 06-15-2004, 07:43 AM

The zex kit bumps fuel pressure by applying vacuum to the fpr or taking away vacuum but it sure works.Also I think its pegged full rich because the plugs are indicating a good mixture,but I'm in the process of hooking up my other stage again without the nos just the fuel.It will work like this I will up my zex to a 125 shot and it will provide as much as it can but for added safety I'll have fuel fogger no nos jetted with a 20 shot ,the parts are cheap and I think it'll be pretty safe and rich,give me some feedback.Oh I have a autometer a/f gauge.

svxfiles · #10 06-15-2004, 08:19 AM

Do you have a fuel pressure gauge? Stock is 36.3, but the pump is capable of much higher. The math formula to find the new flow/output is as follows. Take the new line pressure, say 45psi, and devide it by the original 36.3psi, and you get 1.2396694. Now get the square route of that, (thank God for that calculator function) 1.1134044, and multiply it by the factory rated flow of 275cc/minute and you now have 306.18621cc/minute injectors.

poweredx2 · #11 06-15-2004, 09:40 AM

I am ordering a legacy fuel pressure regulator it has more pressure and I will see can a fuel filter from a 95 civic si work on our cars only because it has a port for an aftermarket pressure gauge to keep an eye on the fuel pump,it won't be the only honda part on my car I already have 95 accord sunvisors with extendions.