Fuel pump stopped suddenly.

[Christian]

Plymouth Voyager 89, 2.5, turbo, 4 cyl.
My van stopped on the road suddenly. After some checking, I notice the
fuel pump (from the tank) does not make the normal noise when put the
contact.
I checked the fuel pressure (on the valve close to injector), not
pressure, not fuel.
Before replacing the pump, is there is any relay which connect the
pump?
What is the simplest way to detect the cause?

Thanks a lot,
Cristian

 

[ulas cosar coskun]

it is my first time i see a fule pump stop suddenly.I guess it will be a
relay or electirical problem. try to eliminate all the other possiblities
before droping the tank. even try to check if you have 12 volt atthe
tank. good lcuk.

 

[Christian]

I checked yesterday with a control lamp.
Under the driver seat there is a contact(connector) which connect the
fuel pump. There are 4 wires for this connector. One of them is dark
green, with a black line, there is not at all 12 volts on this one.
(of course with the contact key put to on, no cranck).
I don't know If I should check all the 4 wires, I read that just the
green/black should have 12 volts on it, but is not.
In this case I suspect the ASD (auto shut-down) relay , not yet the
pump.
May I do a jumper with a wire just to force the 12 volts on the
green/black? A jumper to force the pump to have 12 volts. What about
the others 3 wires which are in the connector?

Thank you,
Cristian

 

[Neil Nelson]

I checked yesterday with a control lamp.
Under the driver seat there is a contact(connector) which connect the
fuel pump. There are 4 wires for this connector. One of them is dark
green, with a black line, there is not at all 12 volts on this one.

That is the Z1 circuit, it (via the ASD being switched on)
is energized for 2 seconds when the ignition is first
switched on to prime the fuel system, it then becomes
energized when the PCM sees the proper RPM signal from the
crankshaft sensor.

(of course with the contact key put to on, no cranck).
I don't know If I should check all the 4 wires, I read that just the
green/black should have 12 volts on it, but is not.
In this case I suspect the ASD (auto shut-down) relay , not yet the
pump.
May I do a jumper with a wire just to force the 12 volts on the
green/black? A jumper to force the pump to have 12 volts.

Yes, you can do this, but I'd use a fused jumper wire in
case there's a short to ground somewhere.
Easiest is to jumper from B+ over to the ignition coil +
terminal since it is in parallel with the circuit you
checked below the drivers seat, or do it both places
depending on what results you get with one or the other.

What about
the others 3 wires which are in the connector?

Guessing off the top of my head;
one is the fuel pump ground.
one is the fuel level sending wire.
one is the fuel level sender ground or
the low fuel warning light.

 

[Lew Barton]

Hi,

I have a '90 Grand Voyager and I have the shop manual, so I checked the
circuits leading to the fuel pump. A friend once had an '89, and I found
that most things were the same between the two. Looking at the fuel pump
wiring, the manual has a 4 wire connector that is indicated near the fuel
tank. Here are the circuits involved:

1. Dk Green/black(#14 gauge so it is a heavy wire) =Fuel pump motor power
(Circuit Z1)

2. Gray (# also 14 gauge wire) = Fuel pump Ground (Circuit X2)

3. Gray (#18 gauge wire-thinner)= Fuel Gauge Ground (at a splice, meets up
with X2)

4. Light Blue (also #18 gauge wire) = Low Fuel warning sensor on fuel gauge
system--turns on low fuel light on dash. (Circuit G40)

There is also a single wire connector nearby that has #18 gauge Dark Blue
wire that is the fuel gauge sensor wire, operating ghe fuel gauge meter.
(Circuit G4)

My vehicle is a 3.3 liter, and the fuel pump went out on a trip about 5
years ago--I think the van had ~70 K miles then. It quit, then after it
cooled down, came back on for a little bit, then I had it replaced.

Hope this helps,

Lew

 

[Daniel J. Stern]

I have a '90 Grand Voyager and I have the shop manual, so I checked the
circuits leading to the fuel pump. A friend once had an '89, and I found
that most things were the same between the two.

Careful, here. Your '89 has a SMEC engine management system, and a '90 has
a SBEC system. The fuel pump is a part of the engine management system.
The hardware is mostly the same, but the wiring and relay arrangement is
different between the two systems.

1. Dk Green/black(#14 gauge so it is a heavy wire) =Fuel pump motor power
(Circuit Z1)
2. Gray (# also 14 gauge wire) = Fuel pump Ground (Circuit X2)

I think you *may* have these backwards. Black (sometimes with tracer)
wires and Z circuits are generally grounds in Chrysler products.

DS

 

[Lew Barton]

Hi,

I rechecked the schematic--it shows what I said. Both wires are marked
X2--one is X2 18GY and the other is X214GY and they both lead to a splice
marked [1<X2> (sorry, this is as close to the box and diamond symbols used
in the manual as I could get with the keys on the keyboard!) and then X2
goes from the splice to a gound lug marked "Body Ground (left rear quarter
panel)"--So, I would say the two gray wires are certainly ground on my unit.
The DG/BK wire goes to <Z1>1] splice which appears to be powered by the ASD
relay.

You are right--the engine controller in my manual is an SBEC unit.