1988 Bad fuel pump

[jammer48]

Hi all, new to the forum... my son just bought a 1988 for 400 bucks and the previous owner told us it needed the fuel pump replaced. So I sprayed some started fluid in the carb to see if it would start and run and it did.... My son then took out the fuel pump while I was at work. When I returned home that evening he had placed it on the work bench so I thought what the heck I am going to put some power to it and see if the pump works. It fired right up and spit out gas all over the work bench. So then I assumed the pump was good and I checked the two fuel related fuses in the fuse box.. they were not burned out. I found a relay on the right engine compartment fender. I think my next step is to hook up the fuel pump again and see if I it will run or is getting power.



Anyone have any other ideas on what I should check next... I really don't want him to just be a "parts changer" I would like him to try and learn something and at the same time we can have a little father/son project.



Thanks in advance... Jamie

[winndixie21]

I would check the connections at the tank for corrosion and check with meter or light for power...
Did you check the fuel filter to see if it was plugged up ? If you have power and pump running, I would check filter and fuel PSI next, pump could run and still not have good or enough pressure .

[jammer48]

Welllll my son pulled the pump out while I was at work and popped the contact points off the top of each post not knowing they were rivotted in place. He did this without me knowing he did.. he was excited to get his pathy running I suppose. Today I am going to check the relays and run the wires down from the relay on the fender and see if I have continuity from the relay to the wires that were connected to the pump/sending unit that was in the tank... I sure could use a wiring diagram of the wire harness going to the fuel pump....

where is the fuel filter on this??? I will check that too

what is the fuel PSI ???

[winndixie21]

Fuel filter is under the hood on passenger side inner fender, easy to get to.

[winndixie21]

Fuel pressure, you would need a fuel pressure tester and connect in line between fuel filter and fuel rail. Start engine , Pressure should read 34 psi with fuel pressure regulator vaccum hose connected... and then disconnect pressure regulator hose from intake and cap vaccum port at intake and start engine and check it again, it should run 43 psi with no fuel pressure regulator connected.
Try to find you at least a chiltons repair manual for it, or a factory service manual .
I have a chiltons and a factory service, and factory wiring diagram service manual for mine.
And if you are going to keep it, you are going to need it.. You can spend a lot of time chasing your tail without one.

http://www.ebay.com/itm/CHILTON-REPAIR- ... 8e&vxp=mtr

[winndixie21]

Is it fuel injected or ?? I just took notice to the year 1988

[jammer48]

Fuel pressure, you would need a fuel pressure tester and connect in line between fuel filter and fuel rail. Start engine , Pressure should read 34 psi with fuel pressure regulator vaccum hose connected... and then disconnect pressure regulator hose from intake and cap vaccum port at intake and start engine and check it again, it should run 43 psi with no fuel pressure regulator connected.
Try to find you at least a chiltons repair manual for it, or a factory service manual .
I have a chiltons and a factory service, and factory wiring diagram service manual for mine.
And if you are going to keep it, you are going to need it.. You can spend a lot of time chasing your tail without one.

http://www.ebay.com/itm/CHILTON-REPAIR- ... 8e&vxp=mtr

wow thanx for the info.... I am going to rent a pressure checker. your right I think the best thing to do now is check the pump to be certain the pressure is correct.... after I disconnect it at the carb and make sure I am getting fuel to the carb. Oh and it is not fuel injected it does have a carb.

THanx for the link for that chiltons I bought it.

Now I need to look for a wiring diagram.

now the 4 buttons at the top of the fuel pump that the wire harness ran into are now just holes in the top of cover.... I was think I could just run the wires through the holes and solder the wires to the correct wires inside the pump cover and then silicone the holes from the top... what do you think???

[smj999smj]

I think you should replace it, not rig it, especially if you want to teach him to do things the right way. Chances are that RTV is not going to last long and the tank will be leaking fuel vapors. You'll also have to be concerned about those wires passing through eventually rubbing through and shorting...and worse: sparking. Sparks and gas fumes are not a good combination unless it's a furness!

[jammer48]

you are correct I hadn't thought about the rubbing... and of course sparks... I have tried to find another but I can only find the pump and not the cover.. you are suppose to replace the pump only and keep the cover.... I am stuck now.....

[jammer48]

UPDATE:
I put the pump on and I have adequate pressure at the carb. If I pour gas in the carb it starts and runs. For some reason the gas is getting to the carb but apparently not into the carb… I think I need to clean the carb? Any thoughts? I really don’t want to take that thing off…. Are there any sensors or relays that might cause this?
Thanx again Jamie….

I did replace the entire pump and sending unit.....

[smj999smj]

Well, it's not a carb but a fuel injection throttle body. With the key on and the fuel injectors unplugged, use a 12v test light to check for power. If you don't have power, you'll need to check the circuit. If you do, a "noid light" can be used to plug into the fuel injectors' harness to to see if the computer is "firing" the fuel injectors. If the noid light flashes when the engine is cranking, but the fuel injector(s) fail to spray fuel, then you may have one or two bad fuel injectors. If either doesn't flash, then you could have an open or short issue on the circuit between the injector(s) and the computer (ECM), bad ECM grounds or a bad ECM.

[jammer48]

so this carb has fuel injectors? Must be what I see on the passenger side of the carb. Thanx for the info I will check the voltage on Saturday and get back to you... thanks again...great info.

[smj999smj]

so this carb has fuel injectors? Must be what I see on the passenger side of the carb. Thanx for the info I will check the voltage on Saturday and get back to you... thanks again...great info.

No, unless somebody converted it to a carb, it doesn't have one. It's a throttle body injection unit with fuel injectors at the top. Is this a Z24i or a VG30i engine?

[jammer48]

your right....

its a vg30i

[smj999smj]

Fuel injectors will be "16021" on the part diagram link below:

http://www.nissanpartszone.com/Page_Pro ... nlPartList