Ranger Starting issue - Not the fuel pump

[got3fords]

Did you try a 1994 Ranger forum?

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[airline tech]

First - You are jumped on the Coil Side of the relay (Horizontal) Pins 85 & 86
You need to Jump the Vertical Pins 30 & 87 (Vertical) for the test

However, it is not needed as if you ZOOM in on the pic, as I suspected (PUSHED CONTACT) on pin 87. Note how far pin 87 it is dropped down vs pin 30

Pin 87 is the power output from the relay to the Fuel Inertia Switch, that the power passes through as its routed to the Fuel Pump.

Get access to the bottom of the Relay Box and push it back up, hopefully the locking tab is not broken, and it will lock, if not it will need a (modification) to hold it in place or a new relay box.

I would check the EEC / PCM Power Relay contacts as well since you will have it opened up.

 

[airline tech]

From my First Post:

Note relays (more importantly) the pins on the relay box are fragile as they age, it is possible you self-induced the no start issue.

For this reason, when swapping relays for T-Shoot, be very careful removing and reinstalling them, it does not take much hand force to push the pins out of place or break them.
Reinstall them with ease and grace and do not force them

 

[Digbird1]

First - You are jumped on the Coil Side of the relay (Horizontal) Pins 85 & 86
You need to Jump the Vertical Pins 30 & 87 (Vertical) for the test

However, it is not needed as if you ZOOM in on the pic, as I suspected (PUSHED CONTACT) on pin 87. Note how far pin 87 it is dropped down vs pin 30

Pin 87 is the power output from the relay to the Fuel Inertia Switch, that the power passes through as its routed to the Fuel Pump.

Get access to the bottom of the Relay Box and push it back up, hopefully the locking tab is not broken, and it will lock, if not it will need a (modification) to hold it in place or a new relay box.

I would check the EEC / PCM Power Relay contacts as well since you will have it opened up.

Thanks so much!, I wasn't sure if that was an issue, But I certainly took out the relay and put it back in a few times now. I don't understand how I get access to the bottom of the relay box to push it back up.

 

[airline tech]

Thanks so much!, I wasn't sure if that was an issue, But I certainly took out the relay and put it back in a few times now. I don't understand how I get access to the bottom of the relay box to push it back up.

At that age (year) it should not be a sealed box and it should be able to be opened up to access the wiring and contacts.
Most likely release tabs somewhere on the box

Ebay Pic

Showing the release tabs on the sides of the box

 

[Digbird1]

At that age (year) it should not be a sealed box and it should be able to be opened up to access the wiring and contacts.
Most likely release tabs somewhere on the box

Ebay Pic

Showing the release tabs on the sides of the box

Do you think I might be able to use a needle nose pliers to pull up the pin? Or would that risk damaging the box?

 

[airline tech]

Do you think I might be able to use a needle nose pliers to pull up the pin? Or would that risk damaging the box?

You may be able to , possibly a micro pair

 

[Digbird1]

You may be able to , possibly a micro pair

The mechanic I usually use had come over and checked before I posted here and after not hearing the pump prime immdeiatley said it's the furl pump, it's frozen, rusted shut or clogged. I forwarded you comments and he said - " So the fuel pump went out before you took the relays out so how does a pin getting pushed down fix the fuel pump?"
I have tried to explain that this module supplys power to the pump. So even if I buy a new pump and install it I would have the same issue if indeed this is the issue. Is that right?

 

[Digbird1]

OOps, I forwarded my mechanic your comments and the pig of the relay box

 

[Digbird1]

OOps, I forwarded my mechanic your comments and the pig of the relay box

Jeez, Spiel check ;-)

 

[airline tech]

Correct, the pushed contact is the supply feed to the Fuel Inertia Switch, as long as the switch is closed (not tripped) then the Pump should be getting power (as long as the wiring from the switch back to the pump is good) - now we have yet to confirm that the Pump is good, but with what you have posted and the truck was running fine (except the starter Issue) then this pushed contact is VERY HIGHLY the point of failure and the reason for not starting.

The relay contact pins (blades) sticking out of it are not long enough to engage the pushed contact.

When the coil in the relay closes - It completes the circuit between Pins 30 & 87, Pin 87 is the power feed to the pump.

For a T-Shoot, if you jumper Pins 30 & 87 - The Vertical (Upper & Lower) Key to Run, to close the EEC Power Relay, the pump should run for a few seconds (prime)

I do not understand his logic, I would ask how the Fuel Pump gets power, it has to be commanded on somehow and in this case it's the relay.

 

[Digbird1]

Correct, the pushed contact is the supply feed to the Fuel Inertia Switch, as long as the switch is closed (not tripped) then the Pump should be getting power (as long as the wiring from the switch back to the pump is good) - now we have yet to confirm that the Pump is good, but with what you have posted and the truck was running fine (except the starter Issue) then this pushed contact is VERY HIGHLY the point of failure and the reason for not starting.

The relay contact pins (blades) sticking out of it are not long enough to engage the pushed contact.

When the coil in the relay closes - It completes the circuit between Pins 30 & 87, Pin 87 is the power feed to the pump.

For a T-Shoot, if you jumper Pins 30 & 87 - The Vertical (Upper & Lower) Key to Run, to close the EEC Power Relay, the pump should run for a few seconds (prime)

I do not understand his logic, I would ask how the Fuel Pump gets power, it has to be commanded on somehow and in this case it's the relay.

So I jumped the fuel pump relay jumper like you suggested, No change. I don't hear the pump prime, although I don't really know what to listen for I don't hear anything. Please see the attached pictures. Especially the zoomed in pic of the module. Do you think that this rules out the relay module?
My mechanic is still adamant that it's the pump. At this point I just need it running.
Thanks again for your help!

 

[airline tech]

OK so the connector (pin) is in place.
As long as you jumpered and then key (on) the pump should have kicked on, on most vehicles if you just turn the key on without starting you will hear the fuel pump kick on (prime) for a few seconds - some are louder than others, you might need a helper listening at the tank while you do this. (if dead silent then the pump is not powering) and it is either the pump or the wiring circuit between the fuel pump relay and the pump - including the Inertia Switch)

There are a few things though -Have you CONFIRMED the fuel pump fuse is good?

Do all lights etc work and the only issue is (no start)?

It does sound like the fuel pump or bad connection

Get a Meter and with the Fuel Pump Relay - Removed

Key On:
Check for Power at Pins 85 (Left Horz) and then Pin 30 (Bottom Vert)
If both of these have power via (Red Lead to pin 85 & Black Lead to Body Ground or (neg battery post)
and same for Pin 30 (Red Lead to pin 30 and Black Lead to Body Ground or (neg battery post)
Power at these pins should match current battery voltage. 12 Volts or whatever it is currently at.

If you have power to those pins, then we can confirm the fuses are good and the PCM Power Relay is good and we know that we have verified power on pin #30, that we can jump from 30 to pin #87, feeding direct power to the pump (with key on)

If no power on both of those pins, then we need to determine the reason why

There is another test and that is done at the DLC on the side of the relay box.
I don't know if it is labeled in any way - but install the fuel pump relay and then go to the DLC connector and jumper (pin #1 or Ck 926) to body ground.
Turn key on - the pump should run

What this is doing is forcing a grd to the (Coil Side) of the relay, thus closing the relay and providing power between pins 30 & 87

This is an alternate way of checking the fuel pump (but with the relay installed)

If you can get access to the Fuel Pump Connector, this alternate way is the proper way to test and verify that if you have power at the connector then you can confirm bad pump
The pump connector is just a 2-pin connector (Power - Pink/Black) and (Ground - Black)

But before you get access to the pump connector (let's check (1) easy access item and that is the Fuel Inertia switch.
To verify power is making it to and past this switch is back probe the connector (T-Pin) and check for power (key on) on both wires (Green/Yellow - Input) and Pink/ Black - Output
Meter - Red Lead to the wire (1 at a time) and Black Lead to Body Ground, should match battery voltage on both wires.

If no power on the pink wire, then the switch is bad or needs reset

If you have power here both in and out, then we can confirm the switch is good and not killing the power feed to the pump.

Sorry, but there is not an easier way to check it for verification without some Indepth wiring troubleshooting.
It appears it's the pump, but I like to verify as much as possible that the part has failed vs wiring control. I hate shot-gunning parts, if they are cheap and easy to replace (yes) I have done it, but for parts that are expensive and hard to get access, I will bend over backwards to verify its bad before I spend money on a part.

So, it boils down to this - if you do not have power at the pump connector (have to get access) then you have a wiring or control circuit issue including the PCM.
If you have power at the connector and have a verified (non-running pump) then it's the pump.
The information I have provided are ways to check for power, I wish the connector was an easy access, as the test would be simple - key on power yes / no but do to the limited access to that connector I have provided alternate (easy) ways to test for power at least to the inertia switch.

There are deeper wiring checks we can do, for the control side, but with you jumping pins 30 & 87 and the pump is not running tells me, it's either a wiring issue / inertia switch issue / fuel pump connector issue or the pump itself.
But the most important is testing for power at pins 30 & 85 with the key on, this will show which direction the issue is. (Upstream or Downstream) power

 

[Digbird1]

OK so the connector (pin) is in place.
As long as you jumpered and then key (on) the pump should have kicked on, on most vehicles if you just turn the key on without starting you will hear the fuel pump kick on (prime) for a few seconds - some are louder than others, you might need a helper listening at the tank while you do this. (if dead silent then the pump is not powering) and it is either the pump or the wiring circuit between the fuel pump relay and the pump - including the Inertia Switch)

There are a few things though -Have you CONFIRMED the fuel pump fuse is good?

Do all lights etc work and the only issue is (no start)?

It does sound like the fuel pump or bad connection

Get a Meter and with the Fuel Pump Relay - Removed

Key On:
Check for Power at Pins 85 (Left Horz) and then Pin 30 (Bottom Vert)
If both of these have power via (Red Lead to pin 85 & Black Lead to Body Ground or (neg battery post)
and same for Pin 30 (Red Lead to pin 30 and Black Lead to Body Ground or (neg battery post)
Power at these pins should match current battery voltage. 12 Volts or whatever it is currently at.

If you have power to those pins, then we can confirm the fuses are good and the PCM Power Relay is good and we know that we have verified power on pin #30, that we can jump from 30 to pin #87, feeding direct power to the pump (with key on)

If no power on both of those pins, then we need to determine the reason why

There is another test and that is done at the DLC on the side of the relay box.
I don't know if it is labeled in any way - but install the fuel pump relay and then go to the DLC connector and jumper (pin #1 or Ck 926) to body ground.
Turn key on - the pump should run

What this is doing is forcing a grd to the (Coil Side) of the relay, thus closing the relay and providing power between pins 30 & 87

This is an alternate way of checking the fuel pump (but with the relay installed)

If you can get access to the Fuel Pump Connector, this alternate way is the proper way to test and verify that if you have power at the connector then you can confirm bad pump
The pump connector is just a 2-pin connector (Power - Pink/Black) and (Ground - Black)

But before you get access to the pump connector (let's check (1) easy access item and that is the Fuel Inertia switch.
To verify power is making it to and past this switch is back probe the connector (T-Pin) and check for power (key on) on both wires (Green/Yellow - Input) and Pink/ Black - Output
Meter - Red Lead to the wire (1 at a time) and Black Lead to Body Ground, should match battery voltage on both wires.

If no power on the pink wire, then the switch is bad or needs reset

If you have power here both in and out, then we can confirm the switch is good and not killing the power feed to the pump.

Sorry, but there is not an easier way to check it for verification without some Indepth wiring troubleshooting.
It appears it's the pump, but I like to verify as much as possible that the part has failed vs wiring control. I hate shot-gunning parts, if they are cheap and easy to replace (yes) I have done it, but for parts that are expensive and hard to get access, I will bend over backwards to verify its bad before I spend money on a part.

So, it boils down to this - if you do not have power at the pump connector (have to get access) then you have a wiring or control circuit issue including the PCM.
If you have power at the connector and have a verified (non-running pump) then it's the pump.
The information I have provided are ways to check for power, I wish the connector was an easy access, as the test would be simple - key on power yes / no but do to the limited access to that connector I have provided alternate (easy) ways to test for power at least to the inertia switch.

There are deeper wiring checks we can do, for the control side, but with you jumping pins 30 & 87 and the pump is not running tells me, it's either a wiring issue / inertia switch issue / fuel pump connector issue or the pump itself.
But the most important is testing for power at pins 30 & 85 with the key on, this will show which direction the issue is. (Upstream or Downstream) power

Thanks again,
I do have lights, and normal accesories turning on, I'll ask the mechanic to bring a voltmeter, But basically he thinks it's the pump freezing up while sitting for a week.

 

[got3fords]

Would the pump run and prime if it is already up to pressure? Meaning, if you are consistently trying to turn the key to hear it, it could have primed once (and not hear it) then it would not have time to bleed pressure off when trying over and over again. Just curious.

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