LS400BOY

So is there a step by step how to change the pump like they did the back seat???

timmy0tool

iTrader: (7)

no step by step like the back seat but see the video (or search other videos) to see what to do when you get the pump out of the tank. it's pretty straightforward.

remember, no smoking around an open gas tank! also keep static electricity at bay by grounding yourself to the car (just discharge yourself by touching metal before handling anything). a small discharge can set off a fire. with that, keep a fire extinguisher or bucket of water nearby!

LS400BOY

Got you thanks everything is helpfull,hope to order a pump soon

randal

Wait...I must have missed how you determined for sure that the pump was (is) the culprit?

LS400BOY

Im almost sure it it,the pump making crazzy noises it never mad before and i dont know if or what could cause this besides it going bad

LS400BOY

This what i found qhen i took out the fuel pump relay,is thia normal? Looks like peanut butter but couls it be factory greese???

randal

It's peanut butter. The squirrels needed a place to store it and looks like you hit the jackpot. ;-)

Seriously, that is electrical grease and keeps the connector from corrosion. So, normal and good.
You should be able to hear a faint click from the relay when you turn the key to 'run'. Or feel it click by just touching the top of the canister while someone turns the key.

LS400BOY

Lol funny, but good advice ill do this tomarrow after work if it does not rain

dicer

The thing to do is check fuel pressure. Then start trouble shooting the electrical etc. back to the pump. You could apply power to the pump to see if it works, remember though that the fuel pump resister helps lower the voltage some.

LS400BOY

Update- changed fuel pump and fuel filter and still dont run???? The relay is is not making noise when key turned over in the on position, should i feel it clicking??? I dont feel or hear anything on the relay itself

dicer

Again do a fuel pressure check.

With trouble shooting you can't just have a fixation on what you "think it maybe". Its a process of elimination.

The relays can go bad, but then again if you have fuel pressure then you know everything pump related is working.
Next is ignition, injector signals, compression, timing etc.

randal

Did you ever feel it clicking before changing the fuel pump? This is exactly what I was hoping you could avoid ...unnecessarily changing components. It just costs you money with no net gain.

Now, it could be that the fuel pressure is good so the relay does not need to click in. Dicer is correct, you really need to get a fuel pressure gauge on the line. Check to make sure you did not leave some connector disconnected. Its the little things that often get missed.

dicer

The fuel pressure gauge would have been less expensive than the fuel pump. And for a simple quick deal just momentarily open a connection on the fuel rail, the fuel spraying out tells you its got pressure. Just have a paper towel or rag handy to capture it.

Maybe find some harbor freight coupons one for the free DMM (Digital Multi Meter) or what ever they what to call it, and a 20% off for the fuel pressure gauge. You could quick check the relay with the DMM of the 4 terminals 2 will be open and 2 will have some continuity or low resistance.

LS400BOY

Well its not making no noise or i dont feel nothing clicking on the relay,it cuts on just for a split sec thats it but i pulled the relay out and tryed to turn the car over it doesnt do nothing but turn over,so im thinking its the relay now after all,i dont even know where the fuel rail at to check the pressure,im used to older chevys lol but im now thinking its the relay,im going to the junk yard and going to pull the 2 relays of 2 of the ls400 thats there and hope
One will work,dont got the money foe a new relay that runs 89-100 bucks

dicer

Here is what the manual says.
Though I am switching around the first 2 steps, since I don't think its a good idea to jumper it with the ignition on.

To check fuel pump operation and to also check the fuel pressure.

1 Jumper the FP and +B terminals of the check connector found on top of the engine on the driver side front.
2 Turn ignition on
3 Check for pressure and or hear fuel return hose. 38 to 44 PSI
(this is how to turn on the fuel pump without the engine running, otherwise there needs to be a signal from engine to run it)

If you have nothing, then here are the causes.

Fusible link
EFI main relay
Fuel pump
Fuel pump resistor
ECU
Fuse EFI (20A) Ign (7.5A)
Circuit opening relay
Fuel pump relay
Wire connections
And added by me (Bad wires)

Okay so the relay is not clicking did you test it like I said? In my list from the manual most of those Items will '
cause the fuel pump relay not to work. You spend too much time ignoring all the good info me and others post here and it already cost you an unnecessary fuel pump and the hassle to change it. Have you even checked fuses, and the connections like the other guy here mentioned? What about the fuel pump resistor? Did you check it? Really your first thing is to obtain is the instrument to check the items listed. And really in the end your fuel pump money would have been better spent on someone that KNOWS HOW TO DIAGNOSE THE PROBLEM. I get a bit grumpy when I go spend time studying for a problem someone else has with their car and then ignores everything I post. Though it does help me if I ever have the problem.