Could this cause me to run lean? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

AndrewM · 12-08-2007, 05:14 PM

I dyno'd my 240 the other day and I was in the mid to low 13's on afr's. I have a redtop sr20det and I just realized today that the vacuum source had come off of my fuel pressure regulator. I was running 12psi and I was lean the whole way. It got a little better as the rpm's went up but still pretty lean. Would that vacuum source have caused me to run lean?

I have an upgraded front mount intercooler and a walbro 255 pump and 12psi. Everything else is pretty much stock. I dyno'd 230rwhp corrected, but Im over 5000ft. above sea level so my actual power was 188rwhp. There is no way I should be out of fuel at 190rwhp, right?

opponheimer · 12-09-2007, 07:23 AM

Damn, thats pretty lean.. Yeah with that vacuum source unplugged, that would have caused you too run lean, unless you have the wrong injectors, and/or your FPR is shot. But you're lucky you caught that, and you're probably fine. Sr's can take a beating. I remember trying out a Megan FPR, and putting fuel pressure to 55 psig, and the car would go to 14:1 AFR at WOT, without me knowing (until I had a friend hook up his wideband.) I have a different motor now though, that one suffered a few dropped valves.

My advice is, get a wideband kit, it'll be the best mod you could ever buy.

wonkuuzenki · 12-10-2007, 03:22 PM

That would definetly cause you to lean out, but not enough to do serious damage to the engine.

go wideband and be happy

12-08-2007, 05:14 PM	#1
AndrewM Join Date: May 2007 Location: New Mexico Age: 44 Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Could this cause me to run lean? I dyno'd my 240 the other day and I was in the mid to low 13's on afr's. I have a redtop sr20det and I just realized today that the vacuum source had come off of my fuel pressure regulator. I was running 12psi and I was lean the whole way. It got a little better as the rpm's went up but still pretty lean. Would that vacuum source have caused me to run lean? I have an upgraded front mount intercooler and a walbro 255 pump and 12psi. Everything else is pretty much stock. I dyno'd 230rwhp corrected, but Im over 5000ft. above sea level so my actual power was 188rwhp. There is no way I should be out of fuel at 190rwhp, right?

12-09-2007, 07:23 AM	#2
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	Damn, thats pretty lean.. Yeah with that vacuum source unplugged, that would have caused you too run lean, unless you have the wrong injectors, and/or your FPR is shot. But you're lucky you caught that, and you're probably fine. Sr's can take a beating. I remember trying out a Megan FPR, and putting fuel pressure to 55 psig, and the car would go to 14:1 AFR at WOT, without me knowing (until I had a friend hook up his wideband.) I have a different motor now though, that one suffered a few dropped valves. My advice is, get a wideband kit, it'll be the best mod you could ever buy. __________________ SR20 & RB20/25/26 in s13/s14 Wiring from $125 to $200.. Best prices EVER.

12-10-2007, 03:22 PM	#3
wonkuuzenki Zilvia Junkie Join Date: Sep 2006 Location: rio rancho, NM Posts: 312 Trader Rating: (0) Feedback Score: 0 reviews	That would definetly cause you to lean out, but not enough to do serious damage to the engine. go wideband and be happy __________________ *Function. Form.* Step Up Drift Club/Upper Limit!