96 Fuel problem

[tempfixit]

96 5.7 engine with 118k

Ran last knight parked it and this morning would not start. Sprayed some starting fluid in the throttle body and runs until starting fluid is gone.

Hooked up fuel pressure gauge but I don't think it is working right because for some reason I don't see a valve in the hose adaptor to hold the schrader valve open. Gauge did show 0 pressurre and I did use a screwdriver to see if there was pressure and very little was present.

There is power at the ECM-B fuse. Testing the 87 terminal of the fuel pump relay I only get around 7volts and I have read that there should be 12V. I also tryed jumper wire from terminal 30 to 87 and did not hear pump run.

I believe it is the fuel pump but the 7 volts at the 87 terminal concerns me. I cannot afford to just throw parts at it right now.

Some advice and the problem would be greatly appreciated.

[MT-2500]

Originally Posted by tempfixit

96 5.7 engine with 118k

Ran last knight parked it and this morning would not start. Sprayed some starting fluid in the throttle body and runs until starting fluid is gone.

Hooked up fuel pressure gauge but I don't think it is working right because for some reason I don't see a valve in the hose adaptor to hold the schrader valve open. Gauge did show 0 pressurre and I did use a screwdriver to see if there was pressure and very little was present.

There is power at the ECM-B fuse. Testing the 87 terminal of the fuel pump relay I only get around 7volts and I have read that there should be 12V. I also tryed jumper wire from terminal 30 to 87 and did not hear pump run.

I believe it is the fuel pump but the 7 volts at the 87 terminal concerns me. I cannot afford to just throw parts at it right now.

Some advice and the problem would be greatly appreciated.

You need to fix or replace your pressure tester adapter.

The orange wire needs 12 volts on it.
If not jumper a 12 volt fuesed jumper to it.
Or and.
Jumper the gray wire or fuel pump test led to fuel pump and see if pump runs and puts out full fuel pressure.
Let us know what you find on that end.

[Johnny Mullet]

I would say it's the fuel pump. Try beating on the fuel tank with a rubber hammer or other non-sparking item while someone cranks it.

[tempfixit]

Thanks for the help guys,

I did get to the fuel pump wiring plug, I could not find a orange wire that you referred to MT. The wire colors are black/whiteStripe, purple, and gray.
With the key on I had 8.69Volts on the purple wire. I did jumper the gray wire and I could hear the pump run but sounded like a slow running pump. The black with white stripe connector ends (both ends) have a green corrision on them. I did spray the ends with some elctric motor parts cleaner.

I did not get a fuel pressure reading tonight as it got dark on me plus I still need to find a new adaptor for it.

What would cause low volts like I am getting?? Would the oil pressure switch have anything to do with this as the gauge does bounce around and it has for probably 4 years now.

Any advice is much appreciated.

[tempfixit]

Today I again jumped the grey wire on the fuel pump and could not hear the fuel pump working so I am going to change the fuel pump.

While taking tank off and attempting to disconnect the fuel lines from the pump housing the housing pipes both broke even after soaking with PB blaster (great to be in the rust belt) Can I use new flared pipe on the frame lines and attach the pump housing lines to frame lines with fuel line hose with hose clamps or is there to much pressure and need the steel pipe line???? I would like to just install a Delphi pump without the sending unit. Carquest and Oreilly's only list the pump and not the pump and sending unit in the Delphi line plus it would be a lot cheaper.

thanks

[Jeremy-WI]

The orange wire would be at the relay socket. Check battery connections for corrosion/tightness, check grounds

I guess I got lucky when I did my pump a couple years ago. A flare fitting should work, some of my water lines use them and I have 60psi and they are used on brake lines and I would think the pressure there could be even higher.

Have you replaced your rear brake line yet, mine finally rusted through

[MT-2500]

Originally Posted by tempfixit

Today I again jumped the grey wire on the fuel pump and could not hear the fuel pump working so I am going to change the fuel pump.

While taking tank off and attempting to disconnect the fuel lines from the pump housing the housing pipes both broke even after soaking with PB blaster (great to be in the rust belt) Can I use new flared pipe on the frame lines and attach the pump housing lines to frame lines with fuel line hose with hose clamps or is there to much pressure and need the steel pipe line???? I would like to just install a Delphi pump without the sending unit. Carquest and Oreilly's only list the pump and not the pump and sending unit in the Delphi line plus it would be a lot cheaper.

thanks

Do not forget to check pump and gauge grounds and fuel pump plugin connection.
If they list a direct OEM type Delphi fuel pump and your gauge and wiring and plugin is good then go for it.
Watch O'Rielly they will slip in a atermarket junk or junk Airtex pump instead of the Delphi pump.
But if gauge and module and fuel line fittings and wiring is not good.
Best to replace the complete module when doing it.
And use only the OEM type delphi pump.
You get new fuel gauge and inside fuel lines and connector and line fittings with it if needed.

On the fuel lines double flared steel lines will work for a splice.
But if lines are bad or rusted best to replace with the OEM lines and fittings
Steel to rubber hose with clamps is riskey.
Good Luck
Your system will have 65-105 lbs of pressure on it.

[tempfixit]

Thanks MT-2500 and Jeremy-WI,

MT do you mean that Oreily's will have AIrtex or other pump in the Delphi Box??

I was thinking of using steel brake line connected to the fuel lines by the frame and then connecting the pump housing lines and frame lines with the special fuel line hose and clamps but like you say MT this could be trouble some later. I know that the Villagers use fuel line hose on their fuel rail connections and can be a pain.

Are the double flare steel lines available at hardware stores or is that a specialty fitting?

Yes Jeremy I did replace the brakeline couple years ago, I had a tough time doing it but got it done without removing the fuel tank.

Quess it's time to remove the fuel pump from tank and see what I actually do have to deal with.

Also thanks for tip on the orange wire Jeremy-WI I see what I can find.

[MT-2500]

Originally Posted by tempfixit

Thanks MT-2500 and Jeremy-WI,

MT do you mean that Oreily's will have AIrtex or other pump in the Delphi Box??

I was thinking of using steel brake line connected to the fuel lines by the frame and then connecting the pump housing lines and frame lines with the special fuel line hose and clamps but like you say MT this could be trouble some later. I know that the Villagers use fuel line hose on their fuel rail connections and can be a pain.

Are the double flare steel lines available at hardware stores or is that a specialty fitting?

Yes Jeremy I did replace the brakeline couple years ago, I had a tough time doing it but got it done without removing the fuel tank.

Quess it's time to remove the fuel pump from tank and see what I actually do have to deal with.

Also thanks for tip on the orange wire Jeremy-WI I see what I can find.

Not unless someone switched it.
But they will sure try to push a junk airtex pump onto you.


If they do pitch it back at them and demand a good delphi pump.
And be sure to open the box and check the brand on it in case they pull a switch.

[tempfixit]

Found and tested orange wire at the relay and had 12.39 volts.

Took the pump out of tank, wires, gauge and tubes look ok to me. I hooked the fuel pump once removed from the housing directly to the battery with 2 short jumpers, I touched the neg. battery terminal 3 times with pump working and 4th time pump failed to work, so the pump works when it wants to.

I'll post results when done.

thanks again for the help people.

[MT-2500]

Sounds like a Airtex pump to me.

[tempfixit]

Bought the vehicle in Nov of 96 with 10k on it and I have never changed the pump. so as much as I know it is the original pump.

[tempfixit]

Installed new BK hanger with sending unit ($109 including strainer, lock ring with o ring) does not include pulsator. Delphi fuel pump using old pulsator ($104 both from NAPA). Truck is running again.

Thanks for all the help.