Zero fuel pressure

[housedavid1956]

No pressure from new low cost fuel pump. Did this a couple weeks ago and after setting a while fired up and had 44 psi. This time will not start and I checked fuel pressure while cranking and it’s zero. Check the relay and fuses and all good.
Any ideas for me before I purchase another(better) fuel pump?
TIA

 

[housedavid1956]

Oops i forgot 2004 LX

 

[housedavid1956]

Update….3 1/2 hrs later the damned thing started up! Gonna check fuel pressure in the morning.

 

[tmoneyallday]

Yeah, I had a NAPA fuel pump and it worked ok but you really need to do OEM. I bought a cheap one from a junk yard to hold me over until I can refurbish mine with all new parts for about 400$

 

[OEMGUY0720]

Wiring is something I would look at as well aside from switching to the ol reliable oem fuel pump.

 

[housedavid1956]

i have 10.7 volts at the fuel pump connector with it unplugged from the pump assy. pump is supplying zero pressure. could the voltage not being 12+ affect the pump performance/longevity?

 

[kevgentile]

i have 10.7 volts at the fuel pump connector with it unplugged from the pump assy. pump is supplying zero pressure. could the voltage not being 12+ affect the pump performance/longevity?

10 .7 volts is normal and within the specified range, spec is 9-14 volts. Remember it's a variable speed pump and regulated by voltage thru the fuel pump ecu.

Where are you testing at? It needs to be metered at the fuel pump ecu. Checking the resistance of the pump is of equal importance as well.
Should be at 0.2-3.0 ohms.

I did a bunch of pump/ecu checks several months ago and have some notes. I may have left them back home in Maryland but I'll look for the service sheet in the FSM and post it up.

 

[kevgentile]

 

[housedavid1956]

10 .7 volts is normal and within the specified range, spec is 9-14 volts. Remember it's a variable speed pump and regulated by voltage thru the fuel pump ecu.

Where are you testing at? It needs to be metered at the fuel pump ecu. Checking the resistance of the pump is of equal importance as well.
Should be at 0.2-3.0 ohms.

I did a bunch of pump/ecu checks several months ago and have some notes. I may have left them back home in Maryland but I'll look for the service sheet in the FSM and post it up.

I am checking it at the connector at the fuel pump assembly. Using the key like starting it but with the power to the pump disconnected.

 

[BnvS]

Yeah, I had a NAPA fuel pump and it worked ok but you really need to do OEM. I bought a cheap one from a junk yard to hold me over until I can refurbish mine with all new parts for about 400$

You can refurbish fuel pumps? really.. i didn't know you can do that.

 

[housedavid1956]

View attachment 3660357

View attachment 3660357

I have not located the fuel pump ECU. Is it the multiplex body module behind the left rear panel near the jack? I am really confused because I took the pump out and can tested it and it pumped great. Put it back in and the engine started right up with 45 PSI pressure. Started right up the 2nd and 3rd time but after waiting 20 minutes to start again….nothing. Zero fuel pressure.
I assume it is intermittent electrical issue.
Any and all suggestions would be appreciated and I have read about a fuel pump ECU bypass mode but haven’t found any How-2 info. Is this a viable option?
David
Biloxi MS