fuel pump

240sxAddict · #1 02-12-2005, 02:40 AM

ok heres the deal i was reading around about the fuel pumps on the sr20 they say that u can use 300zx (basic everyone know) then i read that u can use the supra tt or the infinity. but i want 2 know if this is true (for my ka24de) so i can see wat 2 do with my fuel pump.

nissanfanatic · #2 02-12-2005, 02:51 AM

You could use pretty much any EFI fuel pump on the KA as long as you can get it to physically work. Its a return style fuel system so once the fuel rail reaches a certian pressure(34psi at idle, 42.5psi at WOT) the rest of the fuel is sent back to the tank. I wouldn't try to modify those to make them work. Go with a Walbro 255 from www.enjukuracing.com . Cheap, easy to install, and functional. I got mine on Ebay from them for like $100 shipped. You'll probably see slight gains from it.

D-Bo · #3 02-12-2005, 03:21 AM

check page 7 of my cardomain. i did the walbro 255lph fuel pump install. any questions you have you can ask me

240sxAddict · #4 02-13-2005, 03:16 AM

so wat ur saying is that the fuel pump walbro 255lph is cheaper than any of the other fuel pumps that i said or is it just better??? cuz right now i have the 300xz fuel pump on it but i wanted 2 replace it cuz i have no idea how long it has so i rather put something i know that i put and when i put it..

TatII · #5 02-13-2005, 03:46 AM

a walbro should flow more fuel then the stock Z pump, and its much easier to install becaseu the Z pump has 2 speeds for different fuel flows. since our 240's only flows at one speed, its quit loud all the time.

D-Bo · #6 02-13-2005, 04:07 AM

i couldn't tell you which one is better, but common sense tells me i'd have reliability with the walbro pump.. its your call man.. factor that in with what tat said

240sxAddict · #7 02-13-2005, 04:21 AM

ok well i guess ill go with the walbro u guys convince me lol 120 dollars for a fuel pump wow i could of gotten a real air filter instead of that pepboy or autozone one that the car brought

D-Bo · #8 02-13-2005, 12:16 PM

well hold on now.. what are your plans for the engine?

R.W.240 · #9 02-13-2005, 03:45 PM

Quote:

Originally Posted by D-Bo

well hold on now.. what are your plans for the engine?

A Fuel Pump is a decent mod regaurdless and will support around 350HP

From what I gather the Walbro is the least reliable FP out there. But hell I could get two walbros for the price of one Tomei.

D-Bo · #10 02-13-2005, 03:58 PM

i wouldn't be buying a higher flowing fuel pump before an intake.. to me, it wouldn't make sense cause with a stock intake and higer flowing pump, wouldn't you be running crazy rich?? if its one or the other, it would make sense to me to get the intake

Broke_as_**** · #11 02-13-2005, 04:01 PM

Quote:

Originally Posted by R.W.240

A Fuel Pump is a decent mod regaurdless and will support around 350HP

Quote:

Originally Posted by D-Bo

wouldn't you be running crazy rich??

It's not going to add anything, it's basically build up work, akin to a metal head gasket. At some point you need it but it's not going to do anything for you power wise. A fuel injection system utilizes constant pressure in the line, what supplies that pressure doesn't really matter. You could have an Amish midget with a hand crank in the trunk as long as he is putting up the required psi numbers.

Anyway, a stock 300ZX fuel pump will run a TT Z32 upwards of 600hp and last an easy 100k+ plus miles. Put a 16 volt amp kit on it and you can get more towards 750hp before it becomes a problem. I don't know what the Walbro will do or how long it will last, I've never used it.

D-Bo · #12 02-13-2005, 04:13 PM

oh ok i wasn't thinking.. i'm guessing its the injectors that are the determining factor then right?

Broke_as_**** · #13 02-13-2005, 04:35 PM

Quote:

Originally Posted by D-Bo

oh ok i wasn't thinking.. i'm guessing its the injectors that are the determining factor then right?

Determining what? The fuel injectors like the rest of the system have a maximum capacity and thus puts a limit how much power you can pull from the engine.

The injectors themselves have no bearing on lean/rich conditions, that is all controlled by the ECU. The ECU meters out fuel based on input from various sensors. Given the amount and temperature of the air coming into the engine, current engine rpm, throttle position and a few other things, the ECU tells the injectors to open for X amount of time. And since we have constant pressure in the fuel system we know exactly how much fuel will be released.

nissanfanatic · #14 02-13-2005, 05:54 PM

D-Bo, what I said earlier.

The ECU does determine the A/F ratio. But there are two different modes it operates in.

Closed loop which uses input from the MAFS, O2, water temp, TPS, ect. This mode favors fuel economy and drivability. Usually around a 14.7:1 AF.

Open loop uses only TPS and MAFS. This is the mode you are in when going past about 50% throttle. I believe this mode usually aims for 11:1 AF IIRC. It is rich enough that you could use a piggyback of some sort to take out fuel and acutally gain performance. Both of these modes are determined from load/RPM/airflow tables. These then determine where you are in the fuel map and timing map. Thus why messing with MAFS voltage can shift you into different parts of the timing map. Play tricks on the ECU and you can count on it to play tricks back.

So the ECU can only malfunction and cause rich conditions if one of the sensors are malfunctioning or the ECU itself is malfunctioning. Or if the FPR is malfunctioning. Like I have said before, an upgraded fuel pump is a very good first upgrade. I actually saw performance gains from it.

orestes · #15 02-13-2005, 10:56 PM

so a fuel pump as a first upgrade? did you see gains from it on your stock engine? it doesnt seem like it would, but i suppose if your stock one is worn out a bit you would be losing power.

man i remember my friends Saleen, when you turned the ignition on it was just like BAAAAAAAAAAAAAAAAA loud ass fuel pumps (i think it had 2) but i wouldnt want that noise on all the time while driving.

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