| Author | Message | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 1 Registered: 9-2006 Posted From: 64.61.224.92 Rating: |
While servicing my 6000P Onan today, the fuel pump starting cycling. This started as i was changing the inline filter. I started it from the remote, but could not shut it down from there. The only way to stop the fuel pump was to disconnect the battery. Any ideas on what i can look for or check? TIA, John | ||
| wrench (Metricwrench)
Registered Member Username: Metricwrench Post Number: 5 Registered: 9-2006 Posted From: 208.54.94.73 Rating: N/A |
Better find the problem before you damage the engine, if pump keep going you're going to load the crankcase with gas & tin the the oil to a point where there is no lubrification & damage the engine. wrench | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 173 Registered: 7-2006 Posted From: 4.227.119.236 Rating: N/A |
sounds like the fuel pump or the wire hot all the time TO the fuel pump,but you don't say what fuel,is it gas,propane,or diesel....you could put a switch in the wire that goes to fuel pump | ||
| Bob Wies (Ncbob)
Registered Member Username: Ncbob Post Number: 185 Registered: 2-2006 Posted From: 70.109.11.210 Rating: N/A |
My suggestion is that you check with your local Onan Dealer, not Cummins (they won't tell you much), and describe your problem. Chances are they'll be happy to help you. My guess is that there's a ground on the circuit to the fuel pump relay. Onan generators rely on completed ground to start and stop the units...not B+ like in the automotive world. FWIW Bob | ||
| Denis Fox (Denis)
Registered Member Username: Denis Post Number: 2 Registered: 11-2005 Posted From: 70.39.39.201 Rating: N/A |
John, 2 other items you may want to check: I found that when my remote was installed they had powered it from the bus batteries and the generator has its own battery also. This kept power available at the wrong times! I dont know the 6000P but our diesel has a shut down solenoid that can get involved with a lot of troubles. If you have that check the power to / from also. Good luck, Denis | ||
| Jesse Williams (Buffalo_76)
Registered Member Username: Buffalo_76 Post Number: 15 Registered: 8-2006 Posted From: 205.175.225.5 Rating: |
If it's a diesel gen set, I had a similar problem on an Onan 7.5 Diesel genset in a Pace Arrow Diesel Pusher. Basicly the genset would run intermittently and try to die but not drop completely off line. Eventually it died and wouldn't start. Since I'd had trouble with the primary fuel pump before, I thought it had finally died so I pulled into a Wal-Mart parking lot to replace it with a spare I purchased when I was having this trouble. I wanted to make sure it was in fact the fuel pump so I began troubleshooting. I found that when I pressed the start button either from the remote starter or on the genset unit The fuel pump began running and I could hear the Hobbs Meter clicking away. When I pressed the Stop Switch neither the fuel pump or the Hobbs Meter stopped. I had to open the control circuit breaker on the genset unit to get these to stop. Obviously the fuel pump was not my problem. I thought one of the auto-shutdown features (low oil press or high water temp) might be the problem but the water in the radiator was cool to the touch and there was plenty of oil on the dip stick so I assumed the oil press was probably good. While looking for any problems with these, I noticed a wire that had become disconnected in the area of the injector pump. Turns out the wire was to the "STOP SOLEINOID" Without this wire, the meter and fuel pump will run but no fuel can get to the injector pump. These two items will continute to run because they get the stop signal down stream of the solenoid. I replaced the blade type connector and installed the wire on it's terminal and all was back to normal. Hope this helps, JW | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 2 Registered: 9-2006 Posted From: 64.61.224.251 Rating: N/A |
What a great resource this list is! Thanks to all who helped out. My 6000P is an older air cooled 2 cyl gas engine model. Today i decided to mount a switch up front to control the fuel pump. After getting it hooked up, i tested it two different times. The gen runs ok for about 2 minutes then it appears to load up and almost die. I suspect it is getting way too much gas. I am guessing that the pump is supposed to be controled by some method rather than being on full time. Also the remote shut off failed both times. I had to switch off the fuel pump and let it run out of gas. After shutting the switch off, the gen ran perfect until it emptied the float bowl. I have not been able to track down an owners manual to locate the shut off mechanism, so am at a loss. Plus the gen is bolted into the bay floor, and does not look like an easy removal. If i knew what i was looking for, perhaps i could check it out without removing it. | ||
| Denis (Denis)
Registered Member Username: Denis Post Number: 3 Registered: 11-2005 Posted From: 70.39.39.201 Rating: N/A |
John, I don't know if this will help anymore but here is an Onan site to try: http://www.funroads.com/forum/topicRoot.jhtml;jsessionid=GFSVNTR0CXK0WCTFJMXSFEQ?topicId=2100003&_requestid=645824 | ||
| Jesse Williams (Buffalo_76)
Registered Member Username: Buffalo_76 Post Number: 16 Registered: 8-2006 Posted From: 205.175.225.5 Rating: N/A |
This sounds like it could be a plugged return line from the carburator to the tank or the pressure regulator on the pump (if it has such a thing) not regulating. I'm not sure about generators but on an automobile there is a return line either from the carburator to the tank or from the fuel pump to the tank because the pump can and usually will pump a greater volume of fuel than the engine/carb can handle. That way the engine is assured of a good fuel flow thru all power ranges. Without this return line the engine will not run worth a flip due to too much fuel pressure and the pump will bog down due to the back pressure in the line. Which would account for the fuel pump cycling. It would pump until the pressure built up in the line then stop until the engine burned some fuel then pump again etc. You might try disconnecting the fuel line at the pump and connect to something like an old (clean) fuel tank from a lawn mower or something with a fuel outlet on the bottom so the fuel can gravity feed. Keep this tank above the carb so it will gravity feed and try to start it and see what happens. If it runs good without the pump either the pump is bad or the return line is plugged. After some more thought.... You said this all started when you replaced the fuel filter? Is the filter is an inline filter? If so, is it possible the filter was installed backwards? When you shut off the fuel pump does the engine run about as long as it does before it loads up and almost dies (about 2 minutes)? Sometimes the filters are polar in that they have to be installed so the flow is in the correct direction. If installed backward they may not allow enough fuel thru to keep the engine running under load. I'm at a loss as to the cause of the pump continuing to run after the genset is switched off. One problem at a time I guess. Once again, I hope this helps, JW (Message edited by buffalo_76 on September 28, 2006) (Message edited by buffalo_76 on September 28, 2006) | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 195 Registered: 11-2005 Posted From: 63.97.117.32 Rating: N/A |
John Your carb float valve is stuck open, probably from stale gas gumming it up. Common problem with today's junk gasoline. The open valve makes low pressure to the pump so it keeps on pumping. When the valve closes it presents high pressure to the pump and it either quits or idles, depends on the type. The engine quits after a while with the pump running because it floods and chokes on gasoline. I have a bunch ol old vehicles and this happens all the time with this gasoline. | ||
| christopher l cole sr. (Muziklvr)
Registered Member Username: Muziklvr Post Number: 51 Registered: 7-2006 Posted From: 68.119.224.144 Rating: N/A |
john,i just had the very same problem with the same genset in an allegro class a.the fuel pump on this gensetis a "pulsating" pump,and is not designed to have a constant flow of current to it.if i'm not mistaken,that pump is 3.5 psi.replace the pump.i had wired in a switch also.....replaced pump,and wired just as it was before,FIXED problem.hope this helps. | ||
| William Sloan (Ole_timer)
Registered Member Username: Ole_timer Post Number: 1 Registered: 9-2006 Posted From: 71.10.33.31 Rating: N/A |
Hi John I think Gus is right. I have an old Onan and the pump runs when the carb needs fuel.The switch is in the pump.If the needle and seat are dirty or the floats are bad the pump will keep running because there isn`t any pressure to turn the switch off.Pull the top of the float bowl off and take out the floats .Don`t lose the small spring.The needle sits in the seat on the bottom of the float bowl.If the floats are brass, shake them and see if they have fuel inside if they do they must be replaced as they are too heavy and are holding the needle off of the seat which lets fuel in all the time and thats why the eng. loads up and stalls.there could be a fuel leak between the pump and the carb,but you would have found that by now. Good Luck Ole_timer | ||
| John Zabrocki (John_z)
Registered Member Username: John_z Post Number: 3 Registered: 9-2006 Posted From: 64.61.224.34 Rating: N/A |
Thank you to all who offered help. I think the problem was at least two fold. For one, the float had stuck. I tried to get the fuel pump to shut off after building up pressure against my thumb on the outlet and it just kept cycling so i replaced the fuel pump. I can now use the genset, but i have to disconnect the battery when it is not in use or it will go dead. There must be a short in the switch or someplace, as the remote will start it but not shut it down. Again thanks to all for the help and advice. John Z |
