1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Louie488

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The fuel pump on my 1998 Regal LS2500 is not switching on when I crank the engine. Under normal conditions when I turn the ignition switch to "ON" the fuel pump would cycle for a couple of seconds then stop. Continuing to turn the ignition from "ON" to the "START" position would normally cause the pump to continue to cycle until the engine started. Now, the pump does not run for the brief interval when first turning the ignition key to "ON" position nor does the pump run when the key is in the "START" position. The starter motor does run, and all switches and gauges at the helm respond as normal. Here is a diagram of the fuel pump wiring and relay I made up from looking at my boat:
fuel pump wiring.jpg
If I connect a jumper wire across terminal 30 (Power from Battery - Red/White conductor) to terminal 87 (power to pump - Yellow/Green conductor) the pump runs fine.
Using a voltmeter I checked the voltage at terminal 86 (power from ignition switch?) while cranking the starter motor and saw that there was no reading on the meter.
So I figure my problem lies with the ignition circuity. But I do not know where to begin tracing this back from the pump relay. So where does that small gauge green/white wire leading to relay terminal 86 come from? Does it feed from the J1 or J2 connectors coming out of the ECM or should I be looking somewhere else? Any ideas? Does any one know of a wiring diagram for the 5.7GSI PBYCCE? That would help me trace down the problem.
 

bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Terminal 86 should be ground. You need to measure terminal 85.
 

Louie488

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Thanks, Bruce. I probably misread the labels on the relay. I both terminal 85 and 86 while cranking the starter motor and had no voltage at either terminal.
 

Louie488

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

I meant to say that I tested both terminal 85 and 86 while cranking the starter motor and had no voltage at either terminal. I think the Green/White conductor at the relay is the one that is energized when turning the ignition switch to "START" and the black conductor is ground. Neither shows any voltage when I crank the starter.
 

bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

I don't have a BY manual...only an LK manual. On the LK, one of the relays gets its power from the ECM and the other gets it from the alternator. The only BY manual I could locate online, I could not read the schematic.
 

skydiveD30571

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

The BY manual on "boatinfo" gives a wiring diagram for the carbureted engine fuel pump, but not for the TBI models. Strange. And the troubleshooting says "if no voltage, check related wiring." That is very helpful.
 

JustJason

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Louie488 said:
The fuel pump on my 1998 Regal LS2500 is not switching on when I crank the engine. Under normal conditions when I turn the ignition switch to "ON" the fuel pump would cycle for a couple of seconds then stop.

Unless somebody before you did some real fancy wiring on the boat, I believe your mistaken. As they do not work that way from the factory from Volvo.
 

bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

The BY manual on "boatinfo" gives a wiring diagram for the carbureted engine fuel pump, but not for the TBI models. Strange. And the troubleshooting says "if no voltage, check related wiring." That is very helpful.
It's there. i was just looking at it last night. Basically unreadable wiring diagram the way they have it scanned though.

My brother has a paper version BY.
 

JustJason

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

I have the BY manuals. But in a nutshell they work the same as most of the other Volvos. Yellow/Red from the keyswitch activates the fuel pump relay with the key in the start position. And green from the alternator takes over once the engine has started. And both wires have diodes in them so that 1 can not backfeed into the other. But in any event, the fuel pump only runs with either they key held to start, or with the engine running (via the alternator), and that's it. It does not kick on with the key in the RUN position by itself. At least Volvo didn't wire it that way. And if for some reason the OP's did that, then it would have to have some kind of whacky pressure control switch in it, or some kind of timer circuit.
 

bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

I have the BY manuals. But in a nutshell they work the same as most of the other Volvos. Yellow/Red from the keyswitch activates the fuel pump relay with the key in the start position. And green from the alternator takes over once the engine has started. And both wires have diodes in them so that 1 can not backfeed into the other. But in any event, the fuel pump only runs with either they key held to start, or with the engine running (via the alternator), and that's it. It does not kick on with the key in the RUN position by itself. At least Volvo didn't wire it that way. And if for some reason the OP's did that, then it would have to have some kind of whacky pressure control switch in it, or some kind of timer circuit.
That's how the carb version works. OP has fuel injection. As far as I know, when the key is turned to on, The ECM turns on the high pressure fuel pump for a few seconds. Each relay is fed differently.

I don't believe there are any diodes in the fuel injection version.

Jason, you have a carb or FI?
 
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skydiveD30571

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

The GSI is the fuel injected engine, which makes sense because his wire colors don't match the wire colors on the carbureted wire diagram (which is what Jason is describing).

I looked through the BY manual on boatinfo front to back and there's no wiring diagram for anything other than the carbed engine. The website must not have included them when the pages were scanned it (probably because they weren't readable anyways).
 

JustJason

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Lol... I went here first;
Marine Gasoline Engines for 5.0GLPBYC, 5.0GIPBYCCE, 5.7GSPBYC, 5.7GSIPBYCCE, 5.7GSIPBYDCE - 7797510 - Volvo Penta

And saw the carb in the parts diagram, and didn't look at the numbers closer. They must have taken the TBI out of the parts diagram. Aside from that, these manuals are screwy. If the OP ever responds it would be helpful to know if this engine has any OMC model numbers on it as well. As sometimes there are subtle differences on the joint venture engines. And you have to open a Volvo manual for 1 thing, and an OMC manual for something else.

Now that I have the right part of the books open. The relay trip wire is white/green and is on J2-9. If it's not turning on, step 1 would be checking the fuses/breakers, and step 2 really would be seeing if you have any communication between the ECM and the scan tool/diagnostic laptop.

Or, perform checks in steps 5, 6 and 11 in the charts below.

6rj2e4v.jpg


E3KblFX.jpg


eIlhbUs.jpg


I need better glasses. Or need to pay better attention. 1 or the other.....
 
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bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

If you have the wiring diagram for the BY FI model that would be good too.
 

bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

I looked through the BY manual on boatinfo front to back and there's no wiring diagram for anything other than the carbed engine.
I saw it last night. It sucks. Unreadable.
 

JustJason

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

If you have the wiring diagram for the BY FI model that would be good too.

Jheez..... I'm sure you want it for free to, right?

Well..... Here it is. =)

TRlSmx5.jpg


I might have a better copy of it in another manual. I would have to take a look. But before I do, I'm going to wait and see how far the OP gets, and also see if there are any OMC numbers on the engine as well.

EDIT - I'm not sure how to make it bigger. So copy/pasta this link --> http://i.imgur.com/TRlSmx5.jpg
 
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bruceb58

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Jheez..... I'm sure you want it for free to, right?
In color would be nice! :)

That looks exactly like the LK manual so that's good. I have the paper version. Scanning it might be tough though.

It does show the white/green wire going to the ECM.

First thing I would do is re-seat the J2 connector on the ECM.
 
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Louie488

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

Jason, Bruce, Skydive...Thanks for looking into this. I didn't get a chance to mess around with the engine yesterday. I will try to get on it later today. The diagnostic charts from Jason give me some great clues! I don't know what "TBI" refers to in Jason's post. I will look around on the engine to see if I can see any OMC numbers. It was tricky enough just to be able to locate and then read the Volvo nameplate on the engine.

Looking at step 1 in the charts, I do know that neither the high or low pump cycles when the ignition is first turned on. Also, I did try taking the fuel pump circuit breaker out of the circuit (Shorted across the input and output leads) and that had no effect - so I do not believe the problem is in the breaker.

Thanks again for your help
 

skydiveD30571

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Re: 1998 Volvo 5.7GSI PBYCCE - Fuel Pump Circuitry

TBI = throttle body injected. As in fuel injected into the throttle body instead of each cylinder which is MPI.
 
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