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 > onan 4000 gen dies

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Posted: 08/15/18 03:48pm Link  |  Quote  |  Print  |  Notify Moderator

I'm I the only one with trouble keeping 4000 onan running?
at wits end! Things I have replaced
1- fuel filter

2- fuel pump

3- carburetor

4- replaced gas cap on motor home (Thinking it might not be venting )

gen will run 20 to 30 min and the just stop ,runs perfect until it just stops
.Has anyone fixed theirs and if so what did you find wrong. Only code it will show is code 3 it will not show second code

Kennyg

Green bay, Wi 54303

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Posted: 08/15/18 05:01pm Link  |  Quote  |  Print  |  Notify Moderator

had the same problem and I did the same first three items you mentioned. At the time the Cummins Tech indicated that if those items did not resolve problem, then the next item to look at was the PC control board which of course controls the operation of the fuel pump.
Those first three items cost me approx. $600 including labor. For your info the control board is approx. $348 plus labor.
Wish you luck.


Kennyg

azrving

Oatman

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Posted: 08/15/18 05:43pm Link  |  Quote  |  Print  |  Notify Moderator

Before you buy anything else remove the connector from the card and check for and corrosion. Reinstalling it may give the terminals new bite. If that fixes it remove battery power and clean the terminals well. Check any other connections. You might also to bypass the oil shutdown sensor for testing

* This post was edited 08/15/18 05:57pm by azrving *

Mich F

Plantation, Fl

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Posted: 08/15/18 05:44pm Link  |  Quote  |  Print  |  Notify Moderator

Are you using the right procedure to find the fault code ?
Retrieving an Onan fault code


2014 Itasca Spirit 31K Class C
2016 Mazda CX5 on Acme tow dolly- 4 trips ~ 5,800 mi
Now 2017 RWD F150 with a drive shaft disconnect

to old

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Posted: 08/15/18 06:16pm Link  |  Quote  |  Print  |  Notify Moderator

Ok I fixed it ! replaced the fuel pump again.....
seems onan has a problem with fuel pumps? Thankful I purchased it
Local and not online .Called the onan dealer and told him my
problem he replaced the pump for me and that did the trick.
So I guess I bought a carb when mine was just fine, Thanks for
all the help guys !

azrving

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Posted: 08/15/18 07:12pm Link  |  Quote  |  Print  |  Notify Moderator

Thanks for updating. It helps everyone

OFDPOS

Nor Cal

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Posted: 08/15/18 08:12pm Link  |  Quote  |  Print  |  Notify Moderator

There is a few You tube videos about exactly what you were describing . Runs fine for about 20 minutes then dies.
The videos were saying the dipstick on the 4K gen is off. Too much oil , they go into detail about taking a turkey baster and sucking out a few oz's.

Symptoms : Runs fine for 20 minutes shuts down , will not restart . Let it sit for 20-30 minutes fires right back up only to die again after 15-20 minutes run time.

Alot of people commented saying that fixed the dying problems.
Thought what the heck , I tried it , nope still did the same thing.

Wound up replacing the fuel pump and fuel filter.

With no instructions and being in a tight place , took me an hour and a half to do it, well put the module back in tightened it down to realize I didn't fully tighten down the fuel pump retaining screw/bolt and let a wire harness drop underneath the module, so basically did it twice having to remove the module housing plate to get access to the loose screw/bolt and reroute wire harness.

Now that I know how to do it , could do it again in a half hour or less.

I paid right at $100. for the fuel pump, fuel filter and some fuel line.
RV place wanted $250 to replace the pump.

Changed the oil and put at proper level .
Ran it for 5 minutes, turned the A/C on and let run for 30 minutes .
Turned A/C off let run another 5-10 minutes ran perfect.
Have done this a couple times now, so far so good...

Stim

NE Florida

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Posted: 08/15/18 08:25pm Link  |  Quote  |  Print  |  Notify Moderator

Glad you got it going.
Just another sometimes overlooked item that might help someone else-
fuel tank needs to be at least 1/4 full.
A safety feature to keep from running out of gas when parked.

maillemaker

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Posted: 08/16/18 09:16am Link  |  Quote  |  Print  |  Notify Moderator

I've been fighting my Onan 4BGE spec G generator with the same problem. Runs for about 15 minutes then dies. I have hooked up a spark light tester and I can tell it is dropping spark.

I sent my Flight Systems voltage regulator and control board back to Flight Systems for testing. They were OK, but said VR was borderline. They gave me a good deal on one so I bought a Slip Stick slip ring cleaner and VR for $209. Would have been $70+ shipping for testing anyway.

I have recently replaced a faulty ICM with a used one; It could still be suspect. I tested my coil primary and secondary coils and they were within spec for resistance.

This weekend I'm going to clean the slip rings (currently measuring 80 ohms - should clean if higher than 30) and then install the new VR and the old board and see if it runs. If not, I will replace the ICM.

I already replaced my fuel pump, though I am pretty sure the one I replaced was fine.

Fuel tank is full.

There are 5 electrical components on my genset. Coil, ICM, VR, CB, Fuel Pump.

All are fairly easy to replace yourself. My fuel pump has a bolt that is very hard to get to when the genset is in the RV as the entire genset sits in a heavy steel "tray". The lip of the tray makes it impossible to access the bolt. I solved this by using a small hole saw to cut a hole in the lip which provides access to the bolt with a socket.

The trick with removing the ICM is to remove the two screws holding the bracket in place (do not drop them down into the genset!), and then you have to manually turn the engine until you find the one, single short fan blade and have it line up with the ICM slot. Then, and only then, can you remove the ICM. My genset uses a 3/8" hex bit on the gen head side of the generator to crank it over. Make sure you disconnect spark plugs first so engine can't fire and run and hurt you. It's easier to turn the engine if you take the plugs themselves out.

VR and CB are behind the front panel and are super easy to get at.

Coil is on the back top and a little harder to get to but not impossible on my RV with a hinged swing-down genset mounting.

Coil, about $100
ICM, about $100
VR, about $200
CB, about $200

Steve


1990 Winnebago Warrior. "She may not look like much but she's got it where it counts!"



gmctoyman

Lake Livingston, Texas

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Posted: 08/17/18 08:23am Link  |  Quote  |  Print  |  Notify Moderator

Wish SOMEONE would come out with a 4KW generator, that fits the space, to replace the Onan POS !


Dave W. AKA "Toyman"
KE5GOH - On 146.52
RV's ? What RV's ???
Apache Pop-up
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