randal

I hear you, Dicer. I too, get a bit annoyed when I spend time looking up schematics trying to give some (hopefully) helpful advice and then it is ignored. On the other hand, I can understand how the person with the issue is frustrated and may not want to follow that advice or maybe does not understand what was said. So be it. I will still try to help.

So, LS400BOY, how do you want to proceed? Take a deep breath and let's go at this logically. Only this time, you have to do things in order and not jump the gun. Its your money and if you want to preserve it, listen up.

I think it would be a good idea to see if you can energize the fuel pump for a moment. If you still have the back seat out so that you can hear the pump, jumper FP to B+ as Dicer said and see if you can make the pump run. Alternatively, if you jump pins 4 and 1 on the relay with the ignition key to run, you should hear the pump. Don't keep it running very long if does energize. Just a second. And if you do not have a DVM, get one ASAP.

LS400BOY

Sorry guys im not to much on these cars im a old school carbed chevy kind of guy,so everything undet the hood confuses me,and some of the stuff you guys offer i dont know how to do,i did not test the relay yet because dont have one a the moment,but what did was just to see,i tested the old fuel pump by jumping it with my truck battery and it worked fine

randal

Well I am an old school carburetor Ford kind of guy but that did not prevent me from digging into the new technology. And do not miss those carb days one bit. They were so temperamental.

Can you find the "check connector" with the FP and B markings? And do you have a volt-ohm meter that you can use? This is your first step for some fundamental checks.

LS400BOY

Where is that located and what it looks like,i can go see if i can barrow my neighbors

randal

Go back to post #30 and read Dicers description "1 Jumper the FP and +B terminals of the check connector found on top of the engine on the driver side front."

It is just in front of a rather large vacuum diaphragm.

The check connector is a little plastic box that contains test pins that you can jumper. There is a latch on the side. Just open that and you should see what I mean. The +B pin is the top left-most pin and the FP is the top right-most pin. Top meaning as you look down on it, the closest to the windshield side.

dicer

And you can just look inside that little grey plastic cover and it will show you what is what terminal. And another hint, the fuse boxes covers are the same way they show you what fuse does what.

LS400BOY

I must be slow but whats FP AND +B,im taking all this in and will try tomarrow

Yamae

See pin assignments at the DIAG connector below left edge. Connecting these two enables the fuel pump to work full getting the +12V supply. Usually when the load is light, it is getting the +12V through the fuel pump resistor.

FP: Fuel pump voltage control
+B: +12V supply

Yamae

This may be useful too for a DIYer but some are missing depending on the market.
Especially TD is useful disabling the air suspension.

randal

FP = Fuel Pump, +B = +12v (+battery thru another relay). If you have the ignition switch to "on" and you jumper FB and +B together, you should hear the fuel pump run. If not, there are other problems.

LS400BOY

Ok that helped alot,i will try to report back tomarrow,thanks much

LS400BOY

I cant find it ontop of the motor? Im lost us it under a cover or?

dicer

http://www.lexls.com/tutorials/engine/valvecover.html
Do you see the cap you take off the valve cover to put oil in the engine in the first picture?
Now from that cap towards the center of the engine is a little rectangular greyish box looking thing.
That is it.

LS400BOY

Thank you and i eliminated the ign fuse and efi fuse off the list atleast just got to try the others threw out this week

LS400BOY

So you you say jumper the fp and b thats jump it with jumper cables to the battery correct just making sure