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Discussion Starter · #1 ·
hey i got an ls fuel pump from a friend free. does anyone know the specs for it? i think its a 90-93 but it could be 86-89..but probly a 90-93

is this gonna make any diff. bein i got a automatic dx fuel pump supllying my dohc zc??
 

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Is it an in-tank fuel pump or external? If it is for a late model LS (90-93) it should flow quite a bit more fuel than the stock DX one. The DX one was designed for two injectors while the LS one was designed for a higher revving engine with 4 injectors. Though I have a high output in tank fuel pump on my rex, I am going to have to add a second pump in-line to keep my ZC from leaning out in second gear. Even if the pump flows more fuel, you can always adjust it down with an adjustable fuel pressure regulator....
 

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I knid of figured they were seeing how they only list one part number for a fuel pump for the rex. Still, the LS fuel pump would flow more fuel than the rex one.
 

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Discussion Starter · #5 ·
yea it is just a stock fuel pump but il put it in anywayz..any tips on how to do this also??

dam..tegcrx2...if ur leaning out with a hiflow pump...wat the hell am i doin to mine!! :eek:
 

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does the ls pump really flow more than a crx one?
 

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how the hell are you runnin lean!? with all my mods im STILL running 2 green through all gears and as far as i know im using a 91 DPFI fuel pump
 

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I really can't imagine that the integra fuel pump flows much if any more than a CRX one ( I don't know for sure, but it's a reasonable assumption) if all of the CRX's models use the same pump. The integra injectors are barely larger than the CRX injectors, thus not requiring much more fuel, and they do not run any higher press. at the rail. I don't know of anyone that had problems with a properly functioning stock fuel pump supplying a B16, so why is this swap necessary. If you're going to go through all of the trouble to drop the tank and change the pump, I would recommend a high performance upgrade, not a stock replacement out of a car that is near or exactly identical. To run above, or at a 75 shot of nitrous, you need more than just a pump supplying slightly more than stock. Good intention, but in my opinion, terribly not worth the time and effort to install it!!!!!
 

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It has nothing to do with the injectors (sort of), but the fuel mapping of the ECU and how well your engine flows. This is what determines fuel flow. I have numerous mods to my ZC along with no cat, so it flows exceptionally well. My air/fuel ratio gauge goes into the green for a brief moment, but the fuel pump can't keep up with the engine demand, so it leans out. I am not running stock fuel lines or fuel filter either. I had a special fitting made for the hard line to adapt it to a 8an size fuel line that runs to my Venom hi-flow reusable fuel filter, then to the Venom hi-volume fuel rail, then finally a number 6an size line to the Weapon R fuel pressure regulator. The return line back to the tank is stock size. The problem I have caused to make sure I have enough fuel availble at the injectors is too much volume for the fuel to be stored before it is used. The hi-volume in tank pump can't keep up. This was verified when I discussed this with the techs at Venom. That is why they are sending me an auxilary in-line fuel pump. They are formulas to determine fuel demands on engines and what a fuel pump needs to pump.
By the way, and Integra fuel pump out of a late model LS or GSR does flow more fuel, not pressure. An Integra Type R flows even more fuel than those. They are different pumps and flow rates.
As for replacing the in-tank fuel pump on your rex, boy are you in for a treat. LOL. First, you need to drain all of the gas out of the tank. The tank needs to be dropped and about 4 different fuel and vacum lines need to be disconnected, then you have to unbolt the cover that holds the fuel pump in place. Now you can remove the pump from the tank. An it doesn't come out easily. You have to twist it just right. Installing the pump is just reversing the process. My Integra has an external one, so it takes about 20 minutes to replace where as the rex takes about an hour and half. Hope this clears everything up....:)
 

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with the teg ecu ur leaning out? I really cant belive that u sure ur regulator aint bad i mean u dont have enough hp for ur injecters to make u be running lean. It seems its ur regulator. wut psi are u running ur reg at? Id try another it happened to me before tried my reg off my other motor and problem was solved. May not be ur problem but it may be. It doesnt sound as if ur fuel pump is ur problem
 

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It is a new one (Weapon R) and I am running 50psi. You can watch the fuel pressure drop for a split second when you blip the accelerator, then come back up. I have done all of the diagnostics, and the fuel pump is the problem. I am also running new injectors (264cc). I just can't keep up with the flow demands of the engine. I have not dyno'd the engine, but the motor has gobs of torque. I have to get this resolved before I can activate the nitrous setup.
 

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Ya, if that's one of those "rising rate" regulators, they will lean out all the way until they get to full throttle and a decent RPM. I'm willing to put money down that you could put a stock FPR back on and see better performance than with that Weapon R garbage!! As for the teg pump, exactly how much more does it flow, because it can't be substantial. I only mentioned pressre and the injectors to give an example that the demands of that engine are not extreme by comparison with a CRX, and again, if a B16 with the proper ECU can easily be supported in a CRX on the stock pump, there is no reason to guess that the integra fuel pump is going to give any performance enhancement. It's just like you wouldn't want to use B16 injectors on an Si or ZC as an "upgrade" if you were under 18 lbs. boost, you wouldn't want to put an integra fuel pump in and expect greatly improved performance. Again, for all the labor involved, this really isn't worth the time nor effort.
 

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I thought that too. The stock one was having the same problem. The Weapon R is not a rising rate one like what you need for a turbo or subercharged engine, it is just a fancy fpr with a pressure guage.
By the way, it leans out with my foot into it, not when I let off. The ECU is supposed to cut the injectors off when the throttle is released. This was designed in by Honda to help increase mpg.
 

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damn im gald i got a hatch all i gotta do to get the fuel pump out is pull up the back seat, then unbolt the pump from the tank :)
 

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no need to work hard to get to my fuel pump....my rear is gutted....=)
 

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Discussion Starter · #20 ·
wait..i got a hatch too!!
so u tellin me i just gotta take out the back seat and unbolt it..cuz my friend has a rex and he says u gotta drop the tank??
 
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