Kohler 5ECD Not Running EC62, UU, UF

Discussion in 'Electrical Stuff' started by pyro, Apr 15, 2019.

  1. tony1b2000

    tony1b2000 Member

    145
    Oct 10, 2007
    Salem MA
    350 Sundancer 2010
    496 Mag Seacore Mercruiser , Bravo III
    Thanks pyro. It's running ok. And I just want to get through the season. Blew my budget on Manifolds and risers this year. Will try j. JB weld!

    Yes, the generator is running good at the moment. Just drips every second or two. I don't use it much except for grilling at a cove. need to get 2 months out of it. Will try JB Weld and then put this on a replacement to do for next years budget!
    Thanks for your advise on NOT removing the fitting.
    After reading all the posts on this thread, I am absolutely shocked as to what a poor design this is. This part should have been cooled by the heat exchanger and not salt water :(
     
  2. OzRob

    OzRob Member

    36
    Sep 28, 2017
    Perth, Western Australia
    2007 Sundancer 355 (Int'l Model of the 320DA)
    RayMarine C80
    BowThruster
    2 x 100W Solar Panels
    Mercruiser MX 6.2 MPI with V Drives
    Raw Water Cooled
    As promised, here's a follow up on my Kohler genset issues:

    It's been about 6 months since I by-passed the fuel pump/cooler module on my Kohler genset, running a hose directly from the raw water pump outlet to the heat exchanger inlet. All went well at the time - it started easily and ran fine with no sensor trips.
    The concern was that not cooling the fuel may cause issues with the high pressure pump and/or injector, or maybe some sort of vapour lock.
    Given this was done in the middle of our winter with ambient temperatures around 15-16 Dec C the fact that all worked well wasn't all that comforting - what I needed was some hot weather to really put it to the test.
    Well, summer has arrived with a vengeance and last week we had 4 days straight in excess of 40 deg C.
    Welcome to Western Australia.
    During that period we took the boat over to Rottnest Island, about 20klms off the coast, and after cruising over there at about 25 knots picked up our mooring and decided a coffee would be a good idea. (The beer came later)
    With fingers crossed I pushed the genset start button - and am very pleased to report that it started first time and ran smoothly.
    The interior of the engine compartment was probably well in excess of 50 deg C at that time so I'm now relatively confident that by-passing the module will have no effect on the performance of the genset.
    I believe this is a viable solution that can easily be incorporated when you replace the crappy old module with the very expensive new one!
    Hopefully corrosion issues will now be a thing of the past.
     
  3. ttmott

    ttmott PhD in OCD GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Here is something you might consider from someone who is very intimate with injector systems.
    First the main issue is the Kohler system recirculates the fuel around the HP pump and that recirculation puts a lot of heat in the fuel. Therefore, as you know, that fuel needs to be cooled and consequently the cooling water jacket around the fuel module. Also, the fuel remains in the fuel module for long periods of time which is problematic for the fuel it's self. Simply, a very bad design for an engine that sips fuel. You might want to consider a fuel pressure regulator that has a return hose bib on it and returns the bypass fuel to the fuel tank then completely eliminate the cooling water to the fuel module. This would continuously circulate fuel from the fuel tank and solve all of the issues.
     
  4. pyro

    pyro Member

    110
    Dec 4, 2018
    CT, Long Island Sound
    2008 Sundancer 290
    Twin 5.0L MPI Bravo III
    Kohler 5ecd
    @OzRob: Thanks for the update. This is promising. My biggest concern has never been vapor lock. For that you just need to wait for it to cool, and then you can always switch back to raw water cooling. No damage or safety issue. My concern is the overheat or shortening of life of the fuel pump. Best case you could replace the internal fuel pump, worst you need an entire new module. I am still debating which method to run next year...

    @ttmott: This definitely is the preferred approach, but it seems very difficult to get a return line back to the fuel tank on most boats, which I think is why no one explores this option. Even MerCruiser Cool Fuel Modules don't return the fuel back for this reason.
     
  5. OzRob

    OzRob Member

    36
    Sep 28, 2017
    Perth, Western Australia
    2007 Sundancer 355 (Int'l Model of the 320DA)
    RayMarine C80
    BowThruster
    2 x 100W Solar Panels
    Mercruiser MX 6.2 MPI with V Drives
    Raw Water Cooled
    I think mine works because the genset is only run for relatively short periods, maybe up to 15 minutes.
    I did read somewhere that one owner started the genset at the dock and stopped it again at the end of the day. That might prove problematic if using the by-pass option.
    I agree that returning the excess fuel to the tank would be the best solution - many fuel injected light aircraft engines have this feature.
    It would be possible to run a return line from the module to the tank, but would entail tapping into the fuel cooler module and also the tank in such a way as to ensure there's no possibility of a leak.
    The module can be easily removed to do the job, but a tank can't be removed (on my boat, anyway) without removing the associated engine so would have to be tapped into in-situ or maybe via the vent connection.
    Given the very limited access, that's not a happy thought.
     
  6. douglee25

    douglee25 Well-Known Member

    Jan 13, 2008
    Dallas, TX
    Cruisers 3575
    Twin 7.4l
    Many tanks have extra bungs already welded in. Just remove the plug and get the associated fittings.
     
  7. Stray Current

    Stray Current New Member

    28
    Oct 27, 2019
    New Jersczystan
    2007 260DA
    6.2 Horizon MPI/BravoIII
    Kohler 5ECD
    Glad I found this thread! I also have the dreaded 5ECD shutdown/hot startup gremlin.

    I’m an electrician and certified technician for Kohler residential/light commercial gaseous fueled standby units, but not a marine certified tech. Mine is the first one I’ve seen so far.

    Funny thing is, I work with a Kohler regional distributor regularly and some guy in Australia and another guy with a non-disclosed location on a boat forum have been way more informative!

    I’ve gone through the unit, same symptoms to a t. Replaced a bad oxygen sensor, adjusted valve lash, replaced plugs, wires, anode, and tested compression and spark. All good.

    running the unit on a separate tank didn’t help unless you squashed the primer bulb HARD while hot starting, then it would slowly chug and sneeze up to 3600. Change in load would produce a lean miss. At this point I changed the lift pump, and both filters, as well as cleaned out the pump/cooler assembly. fuel pressure would come to 45 static but it was slow to build and would not hold running. It would almost flatline under load.

    I’m going to order the module and injector. I kind of already had it figured but this thread definitely reinforces my diagnosis.

    this genset will hopefully see a few hundred hours a season using only treated fuel, so fouling should not be an issue going forward

    8EF3AFDD-AF9D-420B-B313-418BB1114ACC.jpeg
     
  8. pyro

    pyro Member

    110
    Dec 4, 2018
    CT, Long Island Sound
    2008 Sundancer 290
    Twin 5.0L MPI Bravo III
    Kohler 5ecd
    It's never good when you can get that camera angle :)

    Let us know what the inside of the pump looks like when you pull it out.
     
  9. Stray Current

    Stray Current New Member

    28
    Oct 27, 2019
    New Jersczystan
    2007 260DA
    6.2 Horizon MPI/BravoIII
    Kohler 5ECD
    IMG_20191003_164708.jpg The boat went to one of the best Mercruiser guys around the day after I took delivery. New SeaCore transom assembly, coupler, joints, starter, flappers, drive service, coolfuel module, and injectors cleaned.

    Followed up by cap, rotor, plugs, wires, IAC filter, belt, idler, elbows and raw pickup hoses. Runs like a dream!

    IMG_20191222_172027.jpg The module didn't show any sign of water intrusion into the fuel side. Suspect the regulator is just shot. Definitely some ethanol snot in there. Pic is after a quick blast of cleaner

    I did have a bit of crystallized salt on the back side of the module, suggesting there may be a weep out of the water jacket.
     
  10. pyro

    pyro Member

    110
    Dec 4, 2018
    CT, Long Island Sound
    2008 Sundancer 290
    Twin 5.0L MPI Bravo III
    Kohler 5ecd
    Your module actually looks like it's in pretty good shape. So maybe you don't have the same issue stemming from corrosion as this thread.

    I think the best solution is to bypass the cooling. OzRob has reported back that his cooling bypass has been running good in the record breaking temps of Australia, however he mentioned he only runs it for 15 min. I have attempted to contact Walbro to see if they could share any info on the temperature spec and if the pump can be run in ambient temperature, not submerged in fuel or actively cooled. Haven't had a response back yet; will follow up with them later this week. Although even burning up a fuel pump, assuming I can get it out without damage, is much cheaper to fix than a corroded module clogging up an injector.

    Stray Current: Since you work with standby generators, do you know of any other fuel pumps used in other models that are air cooled that produce with 45 psi? The constraint is that it can't have a return line to the tank.
     
  11. ttmott

    ttmott PhD in OCD GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    It will not be able to run continuously unless the pump is positive displacement and only comes on when fuel pressure drops like in other non-return systems. The pump will heat the fuel to it's vapor point and will boil the fuel causing vapor lock and eventually damaging the pump motor; but more likely to again shut the generator down due to fuel pressure loss. It's a poor design; the only way out is to either return fuel to the tank and get rid of the cooling, or install an intermediate glycol cooling loop , or live with annual disassembly and maintenance.... Just my thoughts.
     
    Todd320 likes this.
  12. Stray Current

    Stray Current New Member

    28
    Oct 27, 2019
    New Jersczystan
    2007 260DA
    6.2 Horizon MPI/BravoIII
    Kohler 5ECD
    it really doesn’t look too bad, but the back side shows that it’s been weeping salt, albeit very slowly. Unfortunately this type of fuel system really needs cooling. Im not 100% positive but I believe it’s either a uscg or abyc mandate that all gasoline fuel systems are vacuum only up to the apparatus. I’m fairly certain positive pressure fuel line are prohibited anywhere except the injection systems. a leak from a pressurized return line could cause a serious bilge fire.

    it’s been a long time since high school marine trades vo-tech class. I left the industry at 18 so I didn’t kill my favorite hobby.

    the generators I’m actually certified in are exclusively propane or natural gas fired. Anywhere from 410c single cylinder to gm 8.1 liter v8 7-150 kW. I suppose I could dig into the different application of the fuel injected kohler engines, but I suspect there’s nothing equivalent in the equipment world that would work on a marine genset.

    something variable speed with a pressure switch could theoretically work, but good luck with insurance if you’re running some homemade contraption and there’s a fire caused by it.








    a peltier cooler could work as well, or flush every time you return to the dock.

    i will be going the flush route
     
  13. Fancis Lings

    Fancis Lings New Member

    1
    Jan 11, 2020
    Auckland
    1939 High Speed Launch. 22M LOA
    Detroit Diesel 8V92Ti 650HP
    Hi - thank you to all those who have provided information, insights and recommendations on this thread.

    I have a Kohler 4ECD that has succumbed to corrosion of the fuel pump/cooler module after only 20 hours of running. I've removed the genset and it's in my garage pending repair or disposal.

    Thankfully the module housing is still intact with no internal corrosion but the fuel pump is badly gummed up and inoperable. The fuel line was also blocked with a thick goo that I've managed to clean out and I'll send the injector for cleaning.

    I've removed the fuel pump without damaging the housing. I'd like to know if/how I can test the regulator - if that's ok I can simply replace the fuel pump make up a new gasket and reassemble using the 'bypass' solution... any ideas on how I remove and test it please? Also, did anyone find where I might get a replacement regulator if this one doesn't want to play nicely.

    All words of wisdom welcome.

    Frankie (Auckland, NZ)
     
  14. OzRob

    OzRob Member

    36
    Sep 28, 2017
    Perth, Western Australia
    2007 Sundancer 355 (Int'l Model of the 320DA)
    RayMarine C80
    BowThruster
    2 x 100W Solar Panels
    Mercruiser MX 6.2 MPI with V Drives
    Raw Water Cooled
    Just catching up with the recent posts -
    Stray Current - I'm guessing your boat has spent it's life in a fresh water lake. The module is pristine compared to mine and pyro's.
    Walbro / Kohler seem to have their head in the sand on this one - the module is simply not fit for purpose in a saltwater environment - ie. about 98% of the global boating fraternity.
    I've never heard back from them after alerting them to my problem, but then again why would they improve the design and deprive themselves of an ongoing revenue stream in replacement modules.
     
  15. Stray Current

    Stray Current New Member

    28
    Oct 27, 2019
    New Jersczystan
    2007 260DA
    6.2 Horizon MPI/BravoIII
    Kohler 5ECD
    The story I got was that it lived up a river off the Chesapeake Bay until 4 years ago, when it came to nj and lived on a river that’s brackish at high tide and fresh at low. I just changed the original 07 filters. I suspect more than anything it went many seasons unused still winterized with the seacock closed.

    side note, how are you holding up down there? Stay safe!
     
  16. OzRob

    OzRob Member

    36
    Sep 28, 2017
    Perth, Western Australia
    2007 Sundancer 355 (Int'l Model of the 320DA)
    RayMarine C80
    BowThruster
    2 x 100W Solar Panels
    Mercruiser MX 6.2 MPI with V Drives
    Raw Water Cooled
    Yep, that would explain the condition of your module.

    We're OK thanks.
    The fires are mostly on the east coast and are very severe - about 2000 homes and 30 lives lost to date I believe.
    Apparently there are some animated maps of Australia doing the rounds on social media showing the whole country ablaze. Not true.
     
  17. Pilot

    Pilot Member

    209
    May 7, 2009
    Chesapeake Bay
    2009 370 Searay DA
    V Drives
    Twin 8.1's
    Similar issue with my 5ECD Kohler with 210 hours on it. I've put @$3000 into it so far. Thats a couple fuel pumps etc,. The ethanol is the culprit mostly. Mechanic said the units need to be disassembled and cleaned twice a season to keep them running well. The sensors are also very sensitive. Also recommend you check and see if its tied to the CO monitor in the cabin, if so, make sure the expiry date isn't coming due or it will shut the gen down as well. Kohler recommends you double up on the startron in the fuel. Ironically, if it was diesel, you'd have no problems.
     
  18. OzRob

    OzRob Member

    36
    Sep 28, 2017
    Perth, Western Australia
    2007 Sundancer 355 (Int'l Model of the 320DA)
    RayMarine C80
    BowThruster
    2 x 100W Solar Panels
    Mercruiser MX 6.2 MPI with V Drives
    Raw Water Cooled
    Ok, probably the final report on my troublesome genset.

    We had a mild summers day today, about 32 deg C, so we took the boat out with the intention of running the genset for an extended period, as requested by some of you guys, to confirm it will be happy with the cooling water bypass.

    . . and the answer is . . . not really.

    It ran for about 30 - 40 minutes, not precisely sure how long as we were underway and I didn't hear exactly when it stopped, but it was in that ballpark.

    The fault code that stopped it was UF - under frequency - which occurs if the governed frequency falls below 90% for 5 seconds. It restarted promptly but after a few seconds it began to surge with the rpm fluctuating wildly until it finally tripped out again. After waiting for about an hour I tried again and it started and ran great - long enough to boil the kettle for a coffee, after which I shut it down.

    On the basis of my experiences today I believe ttmott's right on the money with his comments about the fuel vaporizing/boiling. Being delivered to the injector in that state is not going to be conducive to smooth, or indeed continued, engine operation.
    The theory is further reinforced by the fact that after allowing it to cool, all was good once again.

    My options now seem to be :
    A - reconnect the hoses in the original configuration and start saving for a new fuel module.
    B - leave the bypass in place and limit the run time to a few minutes.

    Option B is no hardship for me because that's pretty much how we use it anyway, but I can see it's not going to suit most people.

    If you're a glutton for punishment there's also Option C which would involve bleeding the excess fuel back to the tank, or maybe even an Option D, whereby a separate little heat exchanger circuit containing fresh water is designed and installed just for the fuel module.

    Of course the real solution would be for Walbro/Kohler to make the bastard thing out of an alloy that's resistant to salt water, but I can't see that happening any time soon.
     
  19. pyro

    pyro Member

    110
    Dec 4, 2018
    CT, Long Island Sound
    2008 Sundancer 290
    Twin 5.0L MPI Bravo III
    Kohler 5ecd
    Well that's disappointing.
     

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