I have a 2000 nissan maxima and I bought a walbro 255 hp fuel pump.

Before I installed the pump I tested it on a battery and it turned on.

I took the stock fuel pump assembly out and swap it out for the walbro.

I put it back in the tank and nothing the car doesnt start and I cant hear the pump turn on.

the fuse is good and im getting power in the wiring harness for the pump.

I put the stock pump back in there and the car starts fine.

I put the walbro in there and same thing nothing happened. i wired the fuel pump to a battery while in the tank and it turned on


can anyone help here?

 

Ive never removed a maxima fuel pump, but i would say bad ground.

 

ya thats what i would think. bad ground. may i ask why you are putting an unnecessary fuel pump in your car???? your making more work for yourself, let alone not doing it correctly. ide say return the pump first and get a walbro 190. with a 255 you WILL need to upgrade the fuel pressure regulators. a walbro 190 is good for up to 500 hp, proven in the DSM world. so just a little fyi

 

how would it be a bad ground if the stock pump always works when it is installed?

 

As a general rule powering up a fuel pump in the absence of fuel is a no-no. Are you saying the walbro works installed when you wire a battery directly to it?

 

Are all the pins in the connector the same for the stock pump as the aftermarket? If the signal wire is on the ground wire and the power is on the ground and the ground is on the signal wire, see what i mean?
As far as testing the pump you should have some fuel in a little pail or something so you dont burn it out. thats why you also shouldn't run your car out of gas

 

im not running the car without gas and the factory 2 pin harness is matched up right to the wlabro.

 

We're talking about when you originally tested the pump.

 

i tested it for less than 3 seconds

 

Im sure you didnt hurt the pump bench testing it without fuel for a few seconds, but I wouldnt make a habit of it.

 

After all is said and done, either the wrong pump for your car or not wired correctly.


"ya thats what i would think. bad ground. may i ask why you are putting an unnecessary fuel pump in your car???? your making more work for yourself, let alone not doing it correctly. ide say return the pump first and get a walbro 190. with a 255 you WILL need to upgrade the fuel pressure regulators. a walbro 190 is good for up to 500 hp, proven in the DSM world. so just a little fyi"

I just love when members criticize guys for doing something and telling them it's not necessary!

 

the walbro isn't completely unnecessary. Im spraying over a 100hp shot of nitrous. And I do plan on going boost in the next couple of months. the walbro 255 wiring matching up the factory wire. it is a 2 pin harness and power and ground are in the right place. there is nothing wrong with the pump itself.

 

You're right - you need a pump for 100-shot and later boost, and the Walbro is a direct plug-and-play replacement for the factory pump. If it still isn't running, yank out your back seat, get a voltmeter , identify the two pump-power wires going into the tank, shove straight pins through the center of the wires, connect your voltmeter to the pins, and try to start the car.

If you see 12 volts on the pump wires, the problem is in the tank. If not, it's in the wiring - relay or drop resistor, probably. The relay is behind the left kick panel, under the fuse panel.

Otherwise, something is screwy inside the tank - bum connector or a wire pulled loose inside. If problem is in the tank. remove the pump again , leave it connected and get out the straight pins and voltmeter and track it down.

 

Are you sure the wires going from the pump to the cover pluged in good? The are two plugs on the top of the cover and one under it going to the pump.

 

all the wiring is fine I'm getting continuity in all the wires

 

So is the pump not turning on, or are you not getting gas?

DF

 

none of you guys unstand then. im just saying that a 190 is OVERKILL unless you get other fuel modifications to go along with it. am i wrong in saying that, comeon people, you should know this

 

Stock fuel system seems to be good for ~270fwhp.

 

222hp stock plus mods and 125hp shot of nitrous. thats about 350ish give or take

 

Did you try to do what I told you with the volt meter. on checking the voltage you when when you try and crank the car? I had to bypass my cars Fuel Pump Control Module for it to be able to hold 34psi at idle. Reason being is that the control module lowers the voltage when there is no load. So by putting a high pressure pump that needs the actual 12v, when u run it with the module ****, its getting like 10v at idle or w/e, not enough to keep it running properly. I bypassed the thing and right away fuel pressure was perfect without the needle bouncing around like before. This is because now its getting the actual voltage of the car and not being modulated by some drop resistor. MAYBE your car has this, and is not letting it provide enough power to even allow for you to crank it on. Thats why I told you to check wat voltage you get at the plug when u try to prime or start the car.

 

Ya I remember we talked about this on the phone that on day. I didn't get around to doing it up i'll do it tonight and let you know what I fine out.

 

In other words try hot wiring the pump directly to the battery.
Use the wire coming from the oem relay located under the drivrers side kick panel and use this as the trigger for a 30-40 amp relay.

So how to wire new relay;
#86- from fuel pressure harness wire
#87 -to fuel pump
#85 to ground
#30-directly from battery with 30 amp fuse

 

Actually, in my case. All you do is ground the pump directly to the body. Because the stock ground is actually the wire that comes from the control module. So if you just directly ground the pump. it will supply all the voltage from the car.

 

Where is the pump getting its hot power from?

 

From the stock positive wire. The voltage is somehow modulated via the ground. I guess it changes the resistance of the ground when its connected to the module thing. But when u ground the pump directly to the body, u get full voltage.

 

No! use the stock positive wire to trigger the new relay set up as I previously mentioned.

Forget about the voltage being modulated by the ground and the change in the resistance.

 

Well I have already been driving like this for almost 4 months without any problems. full pump see's full voltage. ONLY bad thing is that u get a CEL but that does not bother me since i have a list of codes anyways lol. ur setup will work as well though, im just saying what worked for me. IF he has a module thing

 

my bad i meant to say that a 255 is WAY OVERKILL!!!!

 

So Should I Start With Trying To Ground The Pump To The Body And See If That Will Give Me Full Voltage

 

Seems to be the easiest. Id start with that. Kind of like determining if you need an alternator or a battery. Do the cheapest and easiest first.

 

on my friends dsm we had to run new power and ground wires that were thicker to compensate for the larger draw of power. it all came as a kit with his 255 , but when i had my 255 installed on my max, we did no such thing.

anyone elses 255 really loud, if ur in my trunk, the thing really screams, and outside u hear it over the exhaust at idle(frankencar catback, warpspeed y-pipe).glad i dont really hear it from in the car at all tho.