No fuel supply at pump

[Inventor]

I don't get any fuel coming is to the fuel pump where do I start to look
Thanks

[Isaac-1]

What chassis / engine are we talking about here as I don't see any Workhorse brand products in your signature?

[Inventor]

Originally Posted by Isaac-1

What chassis / engine are we talking about here as I don't see any Workhorse brand products in your signature?

I have roadmaster

[SafariBen]

Assuming this is a continuation of the other forum, how did you arrive at a conclusion of no fuel? Too much going on to speculate, and I don't know that monaco filter set up. Looks like it could be pressurized because of the schrader valve, but the engine would typically pull fuel through the primary filter and water seperator, then the transfer pump would push it through the secondary filter and on to the injection pump. But Monaco could have done something different.

[Inventor]

Originally Posted by SafariBen

Assuming this is a continuation of the other forum, how did you arrive at a conclusion of no fuel? Too much going on to speculate, and I don't know that monaco filter set up. Looks like it could be pressurized because of the schrader valve, but the engine would typically pull fuel through the primary filter and water seperator, then the transfer pump would push it through the secondary filter and on to the injection pump. But Monaco could have done something different.

I arrive at this conclusion because there is no fuel coming in to the primary filter and water separator their is a picture on the previous post with my setup. thanks

[Chargerman]

Did you just change the fuel Filter(s)?

[Inventor]

Originally Posted by Chargerman

Did you just change the fuel Filter(s)?

No I dint do anything to the engine after a trip 4 months ago

[jacwjames]

Fuel flow on my 2002 Windsor with 8.3ISC is tank>primary filer>transfer pump>secondary filter.



Start at the tank, is it full, when you remove the suction line does fuel drain back out of the hose. Reattach the hose.
Go to the primary filter and figure out which hose comes from the tank. Remove hose and either blow through it or used compressed air. This will confirm pickup tube & fuel line aren't plugged.



Remove primary filter and inspect the top, is it all open. I had algae back in 2009 and it almost completely plugged my primary filer, engine still ran but it would have only been matter of time before it didn't. Prefill a new filter with fuel, plug the center hole while you do that, install filter! Cycle the key 4-5 times to purge air.



Not sure on your engine but mine the transfer pump runs for 30-45 seconds, I could hear it when I turn the key. Does yours do the same thing?


If you can hear the pump run break the IN line on the secondary filter, if pump is working then you should see fuel. If not then you might have a problem with the transfer pump.


Attached is a 2006 TSB Cummins put out and it does include an 8.3C engine. The lift pump is a known problem. The gasket can fail and/or the bolts on top get loose and allows the transfer pump to suck air. Ultimately it will leak and has a potential of failing the injector pump due to the air.



I was aware of this issue and kept an eye on mine. In 2020 I did a service on my rig and then took it for a drive. Parked it and was going to clean my rear jacks, when I crawled under the rig I heard the sizzle of fuel hitting the exhaust, never reached the ground but the fuel pump transfer pump was leaking. I tightened the 3 bolts on top but ultimately bit the bullet and installed a FASS transfer pump and eliminated the original lift pump. Now when I turn the key the FASS pump runs and I can see the fuel pressure on my secondary filter come up on the gauge I installed in the dash. It runs all the time and I have ~16psi of fuel to the CAPS pump. FASS also has an added benefit of polishing the fuel, I figure the tank gets filtered 90 gph, so in a day of driving 5-7 times.

[Inventor]

Originally Posted by jacwjames

Fuel flow on my 2002 Windsor with 8.3ISC is tank>primary filer>transfer pump>secondary filter.



Start at the tank, is it full, when you remove the suction line does fuel drain back out of the hose. Reattach the hose.
Go to the primary filter and figure out which hose comes from the tank. Remove hose and either blow through it or used compressed air. This will confirm pickup tube & fuel line aren't plugged.



Remove primary filter and inspect the top, is it all open. I had algae back in 2009 and it almost completely plugged my primary filer, engine still ran but it would have only been matter of time before it didn't. Prefill a new filter with fuel, plug the center hole while you do that, install filter! Cycle the key 4-5 times to purge air.



Not sure on your engine but mine the transfer pump runs for 30-45 seconds, I could hear it when I turn the key. Does yours do the same thing?


If you can hear the pump run break the IN line on the secondary filter, if pump is working then you should see fuel. If not then you might have a problem with the transfer pump.

I don't know where is the transfer pump I hear something clicking somwear in the engine room but I don't know what it is.
I hear everyone talking about pump here pump there where are all this pumps?
My lines are not plugged I just got back from a 800 mile trip no problems.

[SafariBen]

You don't have an ISC like Jacwjames, do you? The mechanical inline injection pump C8.3 has a small pump mounted low on the left side of the engine, so below the secondary filter, and behind and below the big inline injection pump. It is nearly impossible for a young fit person to reach from underneath or above the engine, as it is inside of the frame rail on mine. Yours might be more accessible, but still difficult to pump. Cranking the engine will prime it, but you almost have to get fuel to the pump and relieve the pressure building up on the outlet from the pump.



The clicking could be the intake grid heater. Make sure you are plugged in to keep the batteries up. Crank for 20 seconds max, and wait four minutes between crank attempts. And do not open that filter unless you're able to suck air out and close it fast.

[Inventor]

Thanks good info

[Inventor]

Originally Posted by SafariBen

You don't have an ISC like Jacwjames, do you? The mechanical inline injection pump C8.3 has a small pump mounted low on the left side of the engine, so below the secondary filter, and behind and below the big inline injection pump. It is nearly impossible for a young fit person to reach from underneath or above the engine, as it is inside of the frame rail on mine. Yours might be more accessible, but still difficult to pump. Cranking the engine will prime it, but you almost have to get fuel to the pump and relieve the pressure building up on the outlet from the pump.



The clicking could be the intake grid heater. Make sure you are plugged in to keep the batteries up. Crank for 20 seconds max, and wait four minutes between crank attempts. And do not open that filter unless you're able to suck air out and close it fast.

Plugged in meaning shor power? If I double up with battery charger is the advisable?
The bottom of my rig is totally covered from engine to the step.
If I keep doing the cranking will that purge the air now that I introduce air in the system?

[SafariBen]

I guess you need to confirm that the onboard charger is charging the chassis batteries. If not, then a jumper cable between the house positive, and chassis positive will keep them charged while plugged in. My "inverter" charges 80 amps easy, so no other battery charger is needed if the on board charger is connected to the chassis batteries. Read the voltage to be sure.


If the system is functioning, it will purge the air eventually from cranking. It will help immensely to bleed the air from the secondary filter until it pumps fuel, THEN the primer will have no problem pumping fuel through the injection pump, bleeding the air out and eventually starting.


Let us know how it turns out, or any more questions.

[Inventor]

Assuming the system is sealed and full of air pokets and all the pumps working will the automechanic have a better way of purging the air out?