Lean spike on Nitrous
Thread Starter
Drifting
Joined: Dec 2002
Posts: 1,472
Likes: 1
From: Reynoldsburg oh
Lean spike on Nitrous
Was wondering if there is a solution to a lean spike when the nitrous first kicks on. Besides runnin a 97-99 fuel return system. What happens is when the nitrous comes on a 3100 rpm, for the first 300 rpm the A/F spikes to 14:1 then after 3400 it goes down to 11:1 for the remainder of the pull. I think what is happening is the fuel soleniod is sucking the fuel rail dry for a brief moment, then the fuel catches back up and runs fine. If I put in a bigger fuel pump and injectors, would that help.
Thanks.
Thanks.
Drifting
Joined: Oct 2004
Posts: 1,384
Likes: 8
From: Southwest Virginia
The fuel solenoid can't suck the fuel out of the rail. It simply opens a hole allowing what ever fuel in the rail to come out. My guess would be there is a delay in getting the fuel moving when solenoid opens. N2O is under high pressure, over 1,000 PSI while the fuel is only 60 PSI or so. If both solenoids open at the exact same time the N2O has more force pushing it so it will be in the intake quicker than the fuel. Normally it happens close enough to work just fine. But in your case it may not be close enough. I would try watching the fuel pressure while this is happening, but it don't sound like fuel pressure since it goes right back lean. If the time is short enough I would look into placing a short delay in the N2O solenoid to give the fuel a head start when the system is activated.
What type of system are you using? What type of trigger?
What type of system are you using? What type of trigger?
Drifting
Joined: Oct 2004
Posts: 1,384
Likes: 8
From: Southwest Virginia
Originally Posted by sprayedc5
It is a NX wet kit. It is a 150 shot, this doesnt happen on the 100 shot, just the 150. It is activated by a WOT switch on the gas pedal, activated with a window switch.
How long (in time) does it stay lean? You fuel system is obviously supplying enough fuel since it does go back correct, but maybe your right on the edge of the capacity of the factory system and it can't get that much fuel moving that fast. Have you posted this question over in the FI/Nitrous forum? May get some more thoughts from those guys.
