where is the fuel pump located on 6v92?

[eagle19952]

It's kinda hard to figure out what's going on from a 1000 miles away...but were I you I would (after it is running) (with the fuel line unhooked if that's the only way) or with the electric pump working...
I would go to my fuel tank and decipher which is the feed fuel line and which one is the return, then I would loosen or remove the return line and gage the flow at that point.

My suspicion at the moment is that the electric pump may be in backwards.... is there a fuel flow arrow on the pump ? check that.
I also wonder if the fuel restriction fitting on the return fuel line is the correct one....
I also wonder if the fuel hoses are routed correctly thru the filters...but you say that portion is still "intact" from your cross country trip....

  Ok now I am even more confused. I noticed that there is what looks to be a bolt head underneath the fuel pump that has fuel dripping off it. I removed the bottom or inlet fuel line from the fuel pump and heard a gurgling sound. I tried to start it and it started and ran fine? While running, the inlet line would spit a very small amount of fuel out every 5 seconds, but kept running until I turned it off?

[digesterman]

Make sure your electric pump is hooked up correctly as far as power is concerned, some dc motors will run and pump backwards if hooked up wrong


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[eagle19952]

You do need to minimize the amount of "dry" runs that pump see's....the fuel is the only thing that lubricates the innards of that pump....
Your pump should be sucking fuel out of the filters and feeding to the fuel rail in/at the heads....

That's why I say to get the electric pump going....perhaps move it as close to the tank as possible... then you know it is sucking fuel from the tank...then you can start cracking lines to determine the flows... start at the return at the tank... if it is returning, it should be plumbed correctly.
If it needed re-primed 3 times...it's sucking air some where...

Make sure your electric pump is hooked up correctly as far as power is concerned, some dc motors will run and pump backwards if hooked up wrong

Which is part of why I asked if it was a one wire or two wire pump..

I hooked my air compressor up and got it pumped up to 92 psi, and then started my bus up and ran it to get the air pressure up enough to move it( had to take both fuel filters off and fill them 3 times), but finally got it moved. I figured out that the inlet is the top line and not the bottom line on my fuel pump. I figured this out by taking the top line off and fuel came out it while running. While running when the bottom line was off it would spit fuel out a little and constantly put air out it. What could my problem be?

[harleyman_1000]

You do need to minimize the amount of "dry" runs that pump see's....the fuel is the only thing that lubricates the innards of that pump....
Your pump should be sucking fuel out of the filters and feeding to the fuel rail in/at the heads....

That's why I say to get the electric pump going....perhaps move it as close to the tank as possible... then you know it is sucking fuel from the tank...then you can start cracking lines to determine the flows... start at the return at the tank... if it is returning, it should be plumbed correctly.
If it needed re-primed 3 times...it's sucking air some where...

Make sure your electric pump is hooked up correctly as far as power is concerned, some dc motors will run and pump backwards if hooked up wrong

Which is part of why I asked if it was a one wire or two wire pump..

I'm assuming you asking about the prime pump?

[digesterman]

Prime pump, yes


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[eagle19952]

I'm assuming you asking about the prime pump?

no I am talking about the main engine fuel pump....the drive portion of that pump is engine oil lubed...
the internal gears that move the fuel are lubed by the fuel flowing through it.

why the motor runs with a line off needs to be solved...if in fact I understand what you wrote.

[harleyman_1000]

You do need to minimize the amount of "dry" runs that pump see's....the fuel is the only thing that lubricates the innards of that pump....
Your pump should be sucking fuel out of the filters and feeding to the fuel rail in/at the heads....

That's why I say to get the electric pump going....perhaps move it as close to the tank as possible... then you know it is sucking fuel from the tank...then you can start cracking lines to determine the flows... start at the return at the tank... if it is returning, it should be plumbed correctly.
If it needed re-primed 3 times...it's sucking air some where...

Make sure your electric pump is hooked up correctly as far as power is concerned, some dc motors will run and pump backwards if hooked up wrong



  There is a total of 3 wires going to the pump 2 blue or green(can't see well with flashlight)going to 1 contact and 1 red wire going to the other contact.
Which is part of why I asked if it was a one wire or two wire pump..

[digesterman]

And I was referring to your electric prime pump of course. Hooked one up backwards once, found out they do indeed pump backwards. Easy to check, otherwise sounds like eagle is giving you the best info


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[harleyman_1000]

  There is a total of 3 wires going to the pump 2 blue or green(can't see well with flashlight)going to 1 contact and 1 red wire going to the other contact.
Which is part of why I asked if it was a one wire or two wire pump..

[harleyman_1000]

 The 3 wires I'm talking about hook above the engine fuel pump

[MightyThor]

This probably won't help at all, but here is what I know about my 6V92.  The fuel pump will not pull fuel from the tank.  The fuel pump will usually not pull fuel from the filters.  To get mine primed when I get air in the system I have to crack the supply line at the fuel pump and then prime the system all the way up to the fuel pump.  This is the only way that mine will run and stay running with air in the system.  I don't have an electric prime pump on that engine so I have primed it by pressurizing the tank with a blow gun on my air hose and a rag to seal it in the filler neck.  I am not certain, but it just sounds to me like you have air in the system somewhere.

[eagle19952]

If a Detroit is plumbed properly and the filters filled and installed properly, there is absolutely no reason to have to re-prime for the life of the filters.
There is bad hoses, loose connections or loose filters. I can not think of any other causes to lose prime.

I have run filters for more than two years before changing on my personal stuff.
And never lost prime. But I am very familiar with how my bus runs and when it is "losing power, when something is not "right"
You folks who have "lost prime" need to really dig in and find out the whys ... it is not normal.
Believe it or not, I knew an old Detroit hand who used shaving cream as a last resort to try and find suction leaks....
and starting fluid to find intake leaks.

[harleyman_1000]

How can shaving cream be used to find fuel leaks?

[bevans6]

Suction leaks.  You can sometimes see the fluffy cream kind of cratering as it gets sucked into the leak.  Never tried it (don't use shaving cream) but heard of it.  You used to be able to use WD40 to find intake leaks on gas engines, made the engine speed up, but they changed the formulation to be less flammable.

Brian

[Rick 74 MC-8]

correct me if I'm wrong but doesn't the fuel flow through the primary filter then the engine fuel pump then the secondary filter and into the injectors and back into the fuel tank


                                   Rick