5.7 Volvo Penta Fuel/ throttel body problem

naked truth

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This is my 1st post here Good morning.
I have a Volvo Penta 5.7 with throttel body injection, it is a 1998 model year.
the fuel pumps seem to be within spec, low side is 9 psi and the high side is 30psi. I'm getting fuel to the throttle bodywhere it enters(i've pulled it off and turned the key) so I know I've got good fuel to that point. The fuel does not seem to get into the body. To make this worse it will good for a while and then just not start, it's happened 3 times in 6 months and i use the boat quit a bit. Last time was a vessel assist ride at midnite NFG.
I would really like to get this problem behind me, any help or input will be greatkly apperciated.

Thank you
Randy
 

JoLin

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

How do you know that fuel isn't getting into the body? Not implying that you're wrong, but am curious as to how you determined that.
 

TilliamWe

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

How do you know that fuel isn't getting into the body? Not implying that you're wrong, but am curious as to how you determined that.

You can see the injectors on a TBI. They are above and spray down onto the throttle plates. That's probably how he knows.

There is a screen in each injector. Maybe it's plugged?
 

naked truth

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

I have taken the in line off the body and turned the key on and fuel flows with good pressure. Please keep the ideas comming.
Thanks Randy
 

Don S

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

Have you checked for spark? The ECM has to receive a reference low signal from the distributor in order to keep the fuel pumps running. No spark, no reference low, therefore no fuel pump pressure while cranking, along with no spark = NO start.

When you are turning on the ignition switch, the pumps only run for 2 seconds then shut off.

What's the full model number (including the letters after the numbers) of your engine, year only means the year of the boat, not your engine and drive.
 

naked truth

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

Don Thanks for the responce. I have had Fuel pump issues in the past, so i'm pretty well versed with tring not to burn them out but I'm no mechanic. I will check it and get back later.

Thanks Randy
 

naked truth

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

Thought i sent a message oops.
The serial# is 4110154693B Y type, but I broke the block at the starer so it has been replaced with a new long block.It has run well for about 2 years, though i have had other fuel problems. Please let me know if there are any other questions that might help and thank all of you for the input.

Thanks Randy
 

Don S

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

One more time, do you have spark?
 

wire2

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Re: 5.7 Volvo Penta Fuel/ throttle body problem

Re: 5.7 Volvo Penta Fuel/ throttle body problem

If you want to test an injector, unlock & unplug the connector, use 2 jumper leads to connect 12v to the injector terminals. It should open with a click. If you have fuel pressure, it will spray.
 

JoLin

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

You can see the injectors on a TBI. They are above and spray down onto the throttle plates. That's probably how he knows.

Thanks- the light just went on. I was mis-picturing (is that a word?) the setup in my mind.
 

naked truth

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

I should be able to check the spark this afternoon. I just ASSUMED that spark was good. Where and what is the ECM,I'm not very clear on the acronims that I here and see on the board. Could low battery have any thing to do with this? I have what sounds like good crank, but is that worth a check? At any rate I will check spark and be sure i have a full charge on the system. I will be trying to get problem iceolated this weekend so please keep Q/A comming.
Thank you Randy
 

Don S

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

and could low battery have any thing to do with this?

Depending on how low the battery is, Yes. Unlike a carbed engine that may start when cranking slowly, an EFI engine must be truning over fast enough for the ECM to allow the engine to start.

PS: The ECM is the Engine Control Module. It's the small computer that controls the the engines fuel and ignition systems. It's mounted in front of the Throttle body.
 

TilliamWe

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Re: 5.7 Volvo Penta Fuel/ throttel body problem

... It's the small computer that controls the the engines fuel and ignition systems. It's mounted in front of the Throttle body.

Is that where Volvo puts them?
 
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