Electric Priming Pump on MEP-804A

[hawk-aggie]

Got an MEP-804A on which the electric priming pump doesn't work. The pre-heat function appears to work, as do the gauges, and the engine cranks. The unit that had this gen set drained all the fuel, so the lines probably need to be purged of air. I've put 5 gallons in it. I could troubleshoot the crap out of the primer pump, IF I knew where the thing is located. Does any one know where the electric priming pump is located on an Isuzu-powered MEP-804A? Photo would also be helpful. Thanks.

 

[Guyfang]

Have you down loaded the TM's? There is no electric priming pump. The hand pump is near the IP.

 

[Guyfang]

Hand pump

 

[hawk-aggie]

Hand pump

View attachment 855866

Found the manual pump. The issue I'm having is that I don't hear an electric pump running when I turn the switch to the prime/run position. This is the 1st of 3 15Kw units that we've recently purchased. Haven't done much so far, just tinkering. It cranks, but doesn't start. Haven't had time to purge the fuel lines, but suspect that may clear up the issue. I expected these to work similar to our 5Kw units.

 

[Guyfang]

There is no such thing as a priming pump. Have you downloaded the TM's and read -10 TM?

PRIME & RUN - Energizes generator set run circuits with
auxiliary fuel system de-energized.

You need to understand how the system works. The only electric fuel pump on this set is E2. That pump is for aux operation. This gen set has a mechanical fuel pump. It is notorious for being hard to bleed the air out of the system.

Go to the hand pump. Loosen the output line. Start pumping. when you get fuel out of it, tighten the line. Then loosen the output line on the fuel filter. Hand pump. Loosen the last Injector line, at the injector. (farthest away from the IP) Then start cranking the engine over. If on the 2-3 try nothing happens, have someone hand pump while you crank it over.

Please write your city in the location block.

 

[hawk-aggie]

There is no such thing as a priming pump. Have you downloaded the TM's and read -10 TM?

PRIME & RUN - Energizes generator set run circuits with
auxiliary fuel system de-energized.

You need to understand how the system works. The only electric fuel pump on this set is E2. That pump is for aux operation. This gen set has a mechanical fuel pump. It is notorious for being hard to bleed the air out of the system.

Go to the hand pump. Loosen the output line. Start pumping. when you get fuel out of it, tighten the line. Then loosen the output line on the fuel filter. Hand pump. Loosen the last Injector line, at the injector. (farthest away from the IP) Then start cranking the engine over. If on the 2-3 try nothing happens, have someone hand pump while you crank it over.

Please write your city in the location block.

Thanks. I have the TMs and have scanned them. Haven't had time to focus on the new generators yet.

 

[hawk-aggie]

There is no such thing as a priming pump. Have you downloaded the TM's and read -10 TM?

PRIME & RUN - Energizes generator set run circuits with
auxiliary fuel system de-energized.

You need to understand how the system works. The only electric fuel pump on this set is E2. That pump is for aux operation. This gen set has a mechanical fuel pump. It is notorious for being hard to bleed the air out of the system.

Go to the hand pump. Loosen the output line. Start pumping. when you get fuel out of it, tighten the line. Then loosen the output line on the fuel filter. Hand pump. Loosen the last Injector line, at the injector. (farthest away from the IP) Then start cranking the engine over. If on the 2-3 try nothing happens, have someone hand pump while you crank it over.

Please write your city in the location block.

I was finally able to circle back to working on our 15KW gen sets. We have two (2) 804As and one (1) 804B. One (1) each 804A and 804B are skid-mounted. The other 804A is skid mounted. When I start the two skid-mounted units, they both have an electric pump that you can hear running in the two prime settings on the switch. The trailer mounted 804A does not make that sound in either switch position. I haven't gotten the trailer-mounted unit running yet, and will follow your instructions provided above to bleed the system. Just wanting to know why I don't hear any electrical priming pump working. You say it doesn't have one, but my other 804A apparently does.

 

[Guyfang]

6. Fuel System:
Type of Fuel DF-1, DF-2, DF-A, JP4, JP5, JP8
Fuel Tank Capacity 14 gal. (53 liters)
Fuel Consumption Rate (50/60 Hz):
MEP-804A 1.50 gal. (5.7 liters) per hour
MEP-804B 1.20 gal. (4.5 liters) per hour
Fuel Consumption Rate (400 Hz):
MEP-814A 1.75 gal. (6.6 liters) per hour
MEP-814B 1.40 gal. (5.3 liters) per hour
Auxiliary Fuel Pump:
Voltage Rating 24 VDC
Delivery Pressure 5.0-6.5 psi. (34.5-65.5 kPa.) (max)
Fuel Level Switch:
Type Float
Current 3.0 amps at 6-32 VDC

FUEL SYSTEM
The Fuel System (Figure 2), consists of piping, fuel tank, pump fuel filter (MEP-804B/MEP-814B), transfer pump,
fuel filter/water separator, engine fuel filter (MEP-804B/MEP-814B), injection pump and injectors. Fuel is drawn
from the fuel tank by the transfer pump. After reaching the transfer pump, fuel passes through a fuel filter/water
separator where water and small impurities are removed. The fuel then goes to an injection pump where it is
pressurized and pushed into the injectors. Through the injectors fuel enters the diesel engine combustion
chamber, where it is mixed with air and ignited. The fuel that is not used is returned to the fuel tank via an excess
fuel return line.

The Auxiliary Fuel System consists of an external fuel supply, fuel filter, piping, a 24 VDC auxiliary fuel pump and
a fuel level float switch. When the MASTER SWITCH is set on PRIME & RUN AUX FUEL it actuates the auxiliary
fuel pump and transfers fuel from the external fuel supply to the generator set fuel tank. The fuel level float switch
shuts off the auxiliary fuel pump when the generator set fuel tank is full and reactivates the pump as the level
drops. The FUEL LEVEL indicator indicates fuel level of generator set fuel tank from (E) empty to (F) full in
quarter tank increments.




I was finally able to circle back to working on our 15KW gen sets. We have two (2) 804As and one (1) 804B. One (1) each 804A and 804B are skid-mounted. The other 804A is skid mounted. When I start the two skid-mounted units, they both have an electric pump that you can hear running in the two prime settings on the switch. (this is not possible, in a gen set that is in perfect running condition. The TM tells you that the Aux pump only comes on in the Prime and run AUX position.) The trailer mounted 804A does not make that sound in either switch position. (here, you might have a problem. How ful is the tank? The Aux fuel pump ONLY comes on when the fuel tank is running low. The Fuel level switch tells the AUX pump when to start and stop. ) I haven't gotten the trailer-mounted unit running yet, and will follow your instructions provided above to bleed the system. Just wanting to know why I don't hear any electrical priming pump working. You say it doesn't have one, but my other 804A apparently does.

Show me a picture of the electric fuel pump that runs, and what position it runs in. Unless the gen set has a heater hooked up to it, there can only be one E-Fuel pump. The Aux.

 

[hawk-aggie]

I'll see about photos and video.

 

[hawk-aggie]

6. Fuel System:
Type of Fuel DF-1, DF-2, DF-A, JP4, JP5, JP8
Fuel Tank Capacity 14 gal. (53 liters)
Fuel Consumption Rate (50/60 Hz):
MEP-804A 1.50 gal. (5.7 liters) per hour
MEP-804B 1.20 gal. (4.5 liters) per hour
Fuel Consumption Rate (400 Hz):
MEP-814A 1.75 gal. (6.6 liters) per hour
MEP-814B 1.40 gal. (5.3 liters) per hour
Auxiliary Fuel Pump:
Voltage Rating 24 VDC
Delivery Pressure 5.0-6.5 psi. (34.5-65.5 kPa.) (max)
Fuel Level Switch:
Type Float
Current 3.0 amps at 6-32 VDC

FUEL SYSTEM
The Fuel System (Figure 2), consists of piping, fuel tank, pump fuel filter (MEP-804B/MEP-814B), transfer pump,
fuel filter/water separator, engine fuel filter (MEP-804B/MEP-814B), injection pump and injectors. Fuel is drawn
from the fuel tank by the transfer pump. After reaching the transfer pump, fuel passes through a fuel filter/water
separator where water and small impurities are removed. The fuel then goes to an injection pump where it is
pressurized and pushed into the injectors. Through the injectors fuel enters the diesel engine combustion
chamber, where it is mixed with air and ignited. The fuel that is not used is returned to the fuel tank via an excess
fuel return line.

The Auxiliary Fuel System consists of an external fuel supply, fuel filter, piping, a 24 VDC auxiliary fuel pump and
a fuel level float switch. When the MASTER SWITCH is set on PRIME & RUN AUX FUEL it actuates the auxiliary
fuel pump and transfers fuel from the external fuel supply to the generator set fuel tank. The fuel level float switch
shuts off the auxiliary fuel pump when the generator set fuel tank is full and reactivates the pump as the level
drops. The FUEL LEVEL indicator indicates fuel level of generator set fuel tank from (E) empty to (F) full in
quarter tank increments.

View attachment 888941


I was finally able to circle back to working on our 15KW gen sets. We have two (2) 804As and one (1) 804B. One (1) each 804A and 804B are skid-mounted. The other 804A is skid mounted. When I start the two skid-mounted units, they both have an electric pump that you can hear running in the two prime settings on the switch. (this is not possible, in a gen set that is in perfect running condition. The TM tells you that the Aux pump only comes on in the Prime and run AUX position.) The trailer mounted 804A does not make that sound in either switch position. (here, you might have a problem. How ful is the tank? The Aux fuel pump ONLY comes on when the fuel tank is running low. The Fuel level switch tells the AUX pump when to start and stop. ) I haven't gotten the trailer-mounted unit running yet, and will follow your instructions provided above to bleed the system. Just wanting to know why I don't hear any electrical priming pump working. You say it doesn't have one, but my other 804A apparently does.

Show me a picture of the electric fuel pump that runs, and what position it runs in. Unless the gen set has a heater hooked up to it, there can only be one E-Fuel pump. The Aux.

No photos or video necessary. I must have been hearing things when I operated the switch. No pump noise in the prime position. I stand corrected, sir. Thanks.

Now for another issue with the 804B. Runs great. Connected an ECU to it. During first test, everything seemed to run fine and powered up the ECU once I found the correct setting on the source selector switch. I shut down the generator each time before changing the source selector switch. During the second test, the ECU didn't run. I forgot to shut the generator down when changing the source selector switch. When I did that, I thought I heard something click. After that, I couldn't get power to the ECU without having the Battle Short Switch on. With the Battle Short Switch off, the AC Circuit light would come on but immediately go off. I've done something, but don't know what exactly. Would appreciate some help, preferably without a scolding to read the TM. I have too many vehicles needing work to do much TM reading.

 

[Guyfang]

Now for another issue with the 804B. Runs great. Connected an ECU to it. During first test, everything seemed to run fine and powered up the ECU once I found the correct setting on the source selector switch. (Source Selector Switch. Tell me what this is?) I shut down the generator each time before changing the source selector switch. During the second test, the ECU didn't run. I forgot to shut the generator down when changing the source selector switch. When I did that, I thought I heard something click. After that, I couldn't get power to the ECU without having the Battle Short Switch on. With the Battle Short Switch off, the AC Circuit light would come on but immediately go off. I've done something, but don't know what exactly. Would appreciate some help, preferably without a scolding ( ) to read the TM. I have too many vehicles needing work to do much TM reading.

Did you reset the fault indicator?

 

[Ray70]

Would appreciate some help, preferably without a scolding to read the TM. I have too many vehicles needing work to do much TM reading.

Guy's not scolding you... he's just stating the facts.
You should never be too busy to read how to operate and fix these things correctly, because NOT reading the TM first could cause you to do something ( like switch the AC selector while under power ) that may either damage the machine or God forbid, damage YOU!
Look at it like this, even getting "scolded" is pretty much always better than breaking your generator or getting yourself dead!

 

[robertsears1]

When you say ECU, is that a heat pump? I have several FDECU-5 heat pumps ( Field deployable environmental control units) that I run from my MEP-804a&b gensets. It is a 5 ton heatpump needing 60 amps per phase at 208v Three phase 60 hz. It will show a short about 75% of the time due to the huge inrush of current on the 804a The 804b will work 95% of the time. I have not dug into the 804a yet but it does not seem as reliable as the 804b. If you do not see white smoke out of the exhaust after 10-15” of cranking, it is not going to start. Also the MPU (magnetic pickup) can get some funk on the end but your problem sounds like fuel right now. You can buy the hand pump from eBay for the 804a, search Zexel or Isuzu. I have put about 100 hours on the 804a (46 at purchase). And close to 1000 hours on the 804b.

 

[Guyfang]

I wasn't scolding. A gentle reminder? After all, I am the TM Nag!!

 

[hawk-aggie]

Now for another issue with the 804B. Runs great. Connected an ECU to it. During first test, everything seemed to run fine and powered up the ECU once I found the correct setting on the source selector switch. (Source Selector Switch. Tell me what this is?) I shut down the generator each time before changing the source selector switch. During the second test, the ECU didn't run. I forgot to shut the generator down when changing the source selector switch. When I did that, I thought I heard something click. After that, I couldn't get power to the ECU without having the Battle Short Switch on. With the Battle Short Switch off, the AC Circuit light would come on but immediately go off. I've done something, but don't know what exactly. Would appreciate some help, preferably without a scolding ( ) to read the TM. I have too many vehicles needing work to do much TM reading.

Did you reset the fault indicator?

I don't know what the correct name for the switch that indicates which legs - L1, L2, L3 - are selected. No, I didn't reset the fault indicator.

 

[Guyfang]

I don't know what the correct name for the switch that indicates which legs - L1, L2, L3 - are selected. No, I didn't reset the fault indicator.

If you look close by the switch, you will see its marked S6. Its called AM/VM Transfer switch. And all it is used for is to switch what legs get measured. Not to change what legs have voltage on them. Every time you have a fault light, (Idiot Light), you have to press the reset button.

 

[hawk-aggie]

I don't know what the correct name for the switch that indicates which legs - L1, L2, L3 - are selected. No, I didn't reset the fault indicator.

If you look close by the switch, you will see its marked S6. Its called AM/VM Transfer switch. And all it is used for is to switch what legs get measured. Not to change what legs have voltage on them. Every time you have a fault light, (Idiot Light), you have to press the reset button.

Thanks for the great info. Learning more every day.

 

[hawk-aggie]

Now for another issue with the 804B. Runs great. Connected an ECU to it. During first test, everything seemed to run fine and powered up the ECU once I found the correct setting on the source selector switch. (Source Selector Switch. Tell me what this is?) I shut down the generator each time before changing the source selector switch. During the second test, the ECU didn't run. I forgot to shut the generator down when changing the source selector switch. When I did that, I thought I heard something click. After that, I couldn't get power to the ECU without having the Battle Short Switch on. With the Battle Short Switch off, the AC Circuit light would come on but immediately go off. I've done something, but don't know what exactly. Would appreciate some help, preferably without a scolding ( ) to read the TM. I have too many vehicles needing work to do much TM reading.

Did you reset the fault indicator?

Reset fault indicator - missed that bright red light somehow - all is well now. THANKS!

 

[hawk-aggie]

When you say ECU, is that a heat pump? I have several FDECU-5 heat pumps ( Field deployable environmental control units) that I run from my MEP-804a&b gensets. It is a 5 ton heatpump needing 60 amps per phase at 208v Three phase 60 hz. It will show a short about 75% of the time due to the huge inrush of current on the 804a The 804b will work 95% of the time. I have not dug into the 804a yet but it does not seem as reliable as the 804b. If you do not see white smoke out of the exhaust after 10-15” of cranking, it is not going to start. Also the MPU (magnetic pickup) can get some funk on the end but your problem sounds like fuel right now. You can buy the hand pump from eBay for the 804a, search Zexel or Isuzu. I have put about 100 hours on the 804a (46 at purchase). And close to 1000 hours on the 804b.

See photo for possible answer to your lead-off question.

 

[Guyfang]

Reset fault indicator - missed that bright red light somehow - all is well now. THANKS!

No problem. But maybeeeeeeeeeeeeeeeeeeeeeeeeee, looking into the operators TM would be a good way to relax on Sunday? I am not scolding! Nor nagging, much.