Sr20 running lean under load - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

driftslut91 · 07-23-2011, 05:21 PM

Hey guys, im currently breaking in a type X sr with cams, an upgraded turbo, stock injectors, 300zx fuel filter(new) and vipec ecu. i had it put on the dyno for a break in tune, and seemed to be running fine.
recently driving the car, i realized it was leaning out (reading 25-35 on a innovative wideband)and breaking up under load. approx 3500rpm, when feathering the throttle. the plugs were fouled(white) so i switched them to see if it was just the plugs, and the car fouled them as i drove it around the block a couple times. i thought the warlboro fuel pump might have went so i installed the aeromotive fpr and set it to 43.5 psi to see if i was getting proper fuel. This all worked out fine but I installed it in the line after the stock one so im wondering if the factory one went bad or something?

when the car is at idle or revving in neutral it runs rich. Starts and idles fine but runs hot when its warmed up.
It could be many things. i dont think the factory injectors would shit the bed if im not even boosting the car with them..?
maybe a crappy break in tune?
Any other ideas on things i can diagnose are helpful,
thanks

*TheRealSy90* · 07-23-2011, 05:35 PM

Sounds like two things are wrong here.

Stock Injectors.
Stock FPR.

I'm pretty sure even though you have the Aeromotive FPR, since you still have the stock one on it's limiting your fuel.

driftslut91 · 08-01-2011, 09:03 PM

yeah thats what i figured. I pulled the stock injectors and FPR, and put in some high impedance 750s. I'm just waiting on dyno time now. thanks for the input.

07-23-2011, 05:21 PM	#1
driftslut91 Join Date: Sep 2006 Location: Canada Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	Sr20 running lean under load Hey guys, im currently breaking in a type X sr with cams, an upgraded turbo, stock injectors, 300zx fuel filter(new) and vipec ecu. i had it put on the dyno for a break in tune, and seemed to be running fine. recently driving the car, i realized it was leaning out (reading 25-35 on a innovative wideband)and breaking up under load. approx 3500rpm, when feathering the throttle. the plugs were fouled(white) so i switched them to see if it was just the plugs, and the car fouled them as i drove it around the block a couple times. i thought the warlboro fuel pump might have went so i installed the aeromotive fpr and set it to 43.5 psi to see if i was getting proper fuel. This all worked out fine but I installed it in the line after the stock one so im wondering if the factory one went bad or something? when the car is at idle or revving in neutral it runs rich. Starts and idles fine but runs hot when its warmed up. It could be many things. i dont think the factory injectors would shit the bed if im not even boosting the car with them..? maybe a crappy break in tune? Any other ideas on things i can diagnose are helpful, thanks

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07-23-2011, 05:35 PM	#2
TheRealSy90 Premium Member Join Date: Mar 2009 Location: Maricopa, AZ Age: 30 Posts: 7,679 Trader Rating: (10) Feedback Score: 10 reviews	Sounds like two things are wrong here. Stock Injectors. Stock FPR. I'm pretty sure even though you have the Aeromotive FPR, since you still have the stock one on it's limiting your fuel.

08-01-2011, 09:03 PM	#3
driftslut91 Join Date: Sep 2006 Location: Canada Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	yeah thats what i figured. I pulled the stock injectors and FPR, and put in some high impedance 750s. I'm just waiting on dyno time now. thanks for the input.