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No Power to fuel Pump Hel[p 1994 5.8 L

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Farallon25

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I have a 1994 5.8 fuel injected engine that won't start, There is no power goinng to the fuel pump, I checked fuses, ignition switch and connections with no luck. Anyone out there able to give me some advice? Thanks
 
Re: No Power to fuel Pump Hel[p

........... There is no power goinng to the fuel pump ...........
Click to expand...
Has this pump failed?
Are you replacing this fuel pump, and want to power it up?
Have you tested for power during cranking?

IOW, how/when are you testing for power at the fuel pump......
A) Ignition Key ON only,
or
B) are you testing during engine cranking?????

I believe that just as with the Carbureted engines (that use an electric fuel pump), there must be a means of exciting the pump during low oil pressure (i.e., cranking)!
It may be that a portion of this "start by-pass circuit" is not closing during engine cranking! (during engine cranking, the low oil pressure shut down switch is "open" and must be momentarily by-passed in order to obtain fuel pressure)

Do you own an engine harness/fuel pump wiring schematic for your exact engine/model? This should locate both the low oil pressure switch and the start by-pass circuit for you!

I'm not finding anything for Pleasurecraft, but it may look similar to this;

images


I am not familiar with your system, but I think that I'm safe in suggesting that you start with the engine harness schematic, and go from there.
Hopefully one of the other guys will chime in and offer you a better suggestion.

.
 
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Re: No Power to fuel Pump Hel[p

I would run a jumper from a 12v source to the pump, just to be sure it is not the pump and then go from there.

TM
 
Re: No Power to fuel Pump Hel[p

I ran a seperate hot wire from a 12v power source to the fuel pump and the engine ran fine, I traced the wiring from the pump to the computer module and every thing looks ok
 
Re: No Power to fuel Pump Hel[p

So the pump is good - positive so far.

Like Rick suggested, it's best to get the factory service manual - not only for this issue but any that will arise in the future.

There are a few variation used to control the pump with a computer. One scheme has the pump operate independantly of the computer, another has the computer control a relay, and the third uses an oil pressure switch. If the pump is computer controlled, it should run for about two seconds when the key is turned on.If not, the pump should be energized with the starter circuit.

Without knowing more specifics about your engine (model & serial numbers), it's hard to give you a better course of action.
 
Re: No Power to fuel Pump Hel[p

Thanks, Mark..... I think that you've just added what this thread needed......., a bit more info on how the pump may be excited!
So Mark..... if his pump proves to be OK, yet the engine will not start, he likely has an electrical issue....., whether it be the Computer, or some switching device.... Yes/No?

.
 
Re: No Power to fuel Pump Hel[p

I understand that I can run a sepereate power supply to the fuel pump to get the engine to run, but I would really would like to figure out what the problem is, I looked at the manual online and it shows a 20amp relay located next to the low pressure fuel pump, this engine dosnt have one, the wires run from the low pressure pump to the high pressure pump/Fuel filte rand directlly to the computer module, The last time I started the boat it fired up, I let it run for a few minutes and shut it down, Then it would'nt start. Could it be the computer module? If so where could I buy one? Thanks For all the help.
 
Re: No Power to fuel Pump Hel[p

Rick: yes, concur on electrical issue.

Farallon: where did you find an online manual for a unit that old? You need to determine which control strategy is used and then make sure the existing harness is correct and then trouble shoot it to fix the problem. Most mid-90's units are basic as that's when injection (and the need for electric fuel pumps) was introduced to the inboard world.

You may wanna call the 800 number at the top of the page...they have an excellent selection of factory service manuals and may be able to hook you up.
 
Re: No Power to fuel Pump Hel[p

Farallon25 said:
................ The last time I started the boat it fired up, I let it run for a few minutes and shut it down, Then it would'nt start. Could it be the computer module?
Click to expand...
Mark may know more about this type of ECU/ECM than I do.... I'm sure that he does! I do not know how sophisticated this system is.
It could/may be that the computer is sensing something that would normally dictate a "shut-down" of the fuel pump...... of which may involve a sensor somewhere in the system.

Point being...... it may or may not be the module itself.

My suggestion would be proper diagnostics, rather than throwing parts at it. We can throw enough parts at almost any problem....., and correct the issue. However, when we do this, we willl never learn what the actual issue was, therefore no lesson is learned for future.
Just a thought!

.
 
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