VP 5,7 GSI starting problems(fuel pumps not active on crank)

mklearl

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Yep. It is the one with the grey cap on it. If you buy a fuel pressure gauge it should come with a variety of fittings I think. I bought one and I can't remember but I know I didn't have to search for any fittings for it.
The fact that both pumps run puzzles me a bit. I was thinking that you have been measuring power to both pumps. Although they have power it doesn't mean they are spinning. If they are as you say then you need to verify there is fuel going through them. I'd start with the fuel pressure gauge. When you tune the key on the pressure should build and show on the gauge and then drop. Fuel pressure isn't maintained in the lines when the engine isn't running. You can also check the fuel filter/water Sep filter. If there is no fuel in that then the problem is before that ie anti syphon valve or empty tank? You never know. If you have fuel in the filter it may not hurt to change that. From the filter the fuel is pumped to the vapor separator tank. The vst is a tank that takes fuel and keeps it cool. Your other pump is attached to that. The tank has cooling water running under it so the fuel doesn't turn to vapor thus vapor locking your engine. Inside that tank is a float much like a carb. The float could be stuck and not allowing any fuel into that tank. You can lift the cover to find out. But the pressure gauge should tell you the same thing. If there is no fuel in there AND the pump is working you won't have any pressure.

If you want to hear your motor go vroom vroom dump a couple tablespoons of gas down the tbi and start it. Don't use ether... just straight gas. That will verify spark and confirm a fuel issue.
 

alldodge

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jumped 30 and 87 which made the pumps go on for two seconds and then stop.

You either jumped the wrong connections or something is wrong with your wiring. Jumping across those connections takes the ECM and relay out of the equation and connects power direct to the pump.
 

mklearl

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You either jumped the wrong connections or something is wrong with your wiring. Jumping across those connections takes the ECM and relay out of the equation and connects power direct to the pump.

Will the pump still run if the float in the vst is all the way up?
 

alldodge

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Will the pump still run if the float in the vst is all the way up?

Yes, The pump is in a tank, and the tank is filled by the low pressure pump pushing gas in until the float stops the flow. The float in the tank is just like a carb fuel bowl, as the fuel is used more comes in as the float drops
 

Antti84

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Gents,

I think I am one step closer now..I have however a confession to make,it turned out that I was jumping the wrong relay.(ignition instead of fuel) #facepalm :)
The wire colors on my engine did not match with any of the diagrams available online,so it confused me a bit.

So,as I have been troubleshooting the engine by myslef,I have not been able to verify 100% that both pumps would work.I assumed that they have worked but they don't.So when jumping 30 and 87 on the FUEL relay,The rear one is running but not the front(despite of 12v on the connector)
I tried to start the engine with only rear pump running but no luck.But we are going into right direction I think.

I will need a new pump,does somebody know the flowspecs for the front fuel pump on top of the fuel filtet/water separater.
Knowing that Volvo Penta is very expensive,Can I buy a pump from the local autoparts store for GM or does it have to be Marine spec?

Thanks again for your help
 

Antti84

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Dec 11, 2009
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Here is a picture of the pump that is not working
 

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alldodge

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Good this helps.
No do not buy an automotive fuel pump, you do not want to blow up. Just search "Volvo Penta high pressure fuel pump" and several will show up.

BEFORE you do that, make sure you don't have a bad connection at the pump or connector. If need be, disconnect the pump and run some jumpers from a 12V source direct to the pump.
 

Antti84

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Thanks!

Noted!Are you sure that it should not be a low pressure pump?
I am on volvo penta shop and looking at some drawings and part BOM:s
It stays that the pump in front of the engine is a low pressure pump with Volvo Penta item No 385 4902
 

mklearl

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Apr 21, 2013
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Glad it worked out. All dodge. .. if the needle comes up when the vst is full and stops any more fuel from entering where does the fuel go if still being pumped by the lowl pressure pump? Thanks for the explanation.
 

mklearl

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3858261 I believe is your low pressure pump. Type that into ebay and several aftermarket marine pumps come up.
 
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