Kohler 5ECD Not Running EC62, UU, UF

[Chris Crownover]

Good idea, but if it still leaks wouldn’t the fitting kind of be stuck?

Also it’s kind of weird the further I screw into the fuel pump the more it threads out of the wierd fitting on the other it’s like you can’t make either of them right

 

[douglee25]

Is one of them reverse threads? I wouldn't think so?

 

[Chris Crownover]

Is one of them reverse threads? I wouldn't think so?

Yes

 

[douglee25]

Then you'll have to screw one in one way, the other in the other way.

 

[Chris Crownover]

Then you'll have to screw one in one way, the other in the other way.

And then neither one of them is tight but put sealant

 

[douglee25]

You'll have to rotate the entire pump with the fitting in it to screw it in correctly.

 

[Chris Crownover]

You'll have to rotate the entire pump with the fitting in it to screw it in correctly.

Yeah I can do the pump side on the bench but when I go to thread it into the other elbow fitting I’d be screwing it out

 

[douglee25]

Can't you rotate the entire pump and fitting as one unit when you try to thread it into the fuel rail side?

 

[Chris Crownover]

Can't you rotate the entire pump and fitting as one unit when you try to thread it into the fuel rail side?

There isn’t clearance to do that, but the tightening sequence is definitely important for this

 

[douglee25]

Well then I don't see how you're going to get the two pieces together. Unless there's a union or another way to separate the parts. Maybe you'll have to make an extension and remote mount the pump further away? I would have to see it to really make a good assessment on it.

 

[Chris Crownover]

Well then I don't see how you're going to get the two pieces together. Unless there's a union or another way to separate the parts. Maybe you'll have to make an extension and remote mount the pump further away? I would have to see it to really make a good assessment on it.

I disassembled it further down where the fuel line connects, this is def the way to do it

 

[douglee25]

I disassembled it further down where the fuel line connects, this is def the way to do it

#Boom!

 

[Lenny3]

I’m following this post any many like it on another forum to try and figure out my Generator issue.
My genset shut down and I had very little fuel pressure at the nozzle so I had the high pressure pump replaced ($2000.00 labor included). Tech only ram it for 15 minutes, said it was fixed.

Had my buddy take the boat out and Gen set shut off going out the marina.

Tech came back and looked at it and had a code ec69 (O2 sensor). Only way he could get engine to run was to remove the spark plug from rear cylinder$&@?! (rear spark plug removed). I was told the genset had piston and or valve issues and genset needed to be removed from the boat. (Another $2000)

Something didn’t sound right so I decided to take a peek myself, so, first thing I did was to try and start manually. No start. I removed the wire to the sea water pressure switch and bingo! It started! After 5 min. it shut off with code ec69 I read a post about the fuel injector being dirty so I removed it, and checked the spray pattern and sure enough it was very weak and not atomizing correctly. I hooked up a 12v switch to activate the solenoid on the injector and sprayed it with carburetor cleaner until I had a nice spray pattern I installed in genset and she fired right up and has been running for 3 1/2 hours! (sea water pressure switch is in order)
Hope that helps someone!
Lenny

 

[jmauld]

I have been having issues with my Genset this year. It finally got to the point where it just wouldn’t start at all. I opened it up tonight, replaced the plugs, plug wires, fuel filter and seawater impeller, and now it runs great……. For about 15 minutes. At which point it shuts down and returns a UU, UF, 62 or some combination of those codes. Seems similar to the issue described here. I’m not currently at the boat, but I suspect that I need to order a new fuel cooler. This coincides with the cool fuel pumps on my 8.1s failing this year. (Between these pumps and new manifolds, I’m hoping the repair bills will be done for this year).

I have the 7.3ecd low-co model, and I don’t see a parts list specific to this model. Is this part number Gm54991 the correct part number for my Genset?

Should I also order the pump that’s beneath the cooler, or should this pump still be okay?

 

[Lenny3]

Code 62 is a low water flow sensor code. That sensor is located on the front of the heat exchanger. There are 2 wires on it, try unplugging one of the wires, start genset and just watch for water pumping. If it continues to run with the wire unplugged, I would bet the sensor is bad (very common failure) part #
GM30263

 

[Lenny3]

Code 62 is a low water flow sensor code. That sensor is located on the front of the heat exchanger. There are 2 wires on it, try unplugging one of the wires, start genset and just watch for water pumping. If it continues to run with the wire unplugged, I would bet the sensor is bad (very common failure) part #
GM30263

Also UU and UF codes will show up when genset shuts down unexpectedly. High pressure fuel pump modules do fail but before I would replace one I would check the pressure output (40 psi) and clean or replace the fuel injector first

 

[jmauld]

Code 62 is a low water flow sensor code. That sensor is located on the front of the heat exchanger. There are 2 wires on it, try unplugging one of the wires, start genset and just watch for water pumping. If it continues to run with the wire unplugged, I would bet the sensor is bad (very common failure) part #
GM30263

Thanks I’ll do that test this evening. Is there a recommended fuel pressure gauge that I should pick up that has fittings for both the 8.1 mercruisers and the Kohler Gensets?

I think those three codes are given because it doesn’t do a clean shut off. It’s trying to run, it just loses rpm and sputters for 20-30 seconds before shutting down.

 

[Lenny3]

The fuel injector has a Schrader valve on the on it where you would hook up a fuel gauge to.(see attached Pic) I think Mercruiser has the same Schrader valve as well. The problem is you need a 90 degree adapter. So, any fuel gauge would work you just need the adapter. A quick search on the web produced a few adapters and some low cost fuel gauges. FYI..This injector can be cleaned by removing the injector from the mount, hook up a 12 volt battery with a switch and spray with carburetor cleaner and compressed air until you get a good atomization.

 

[Lenny3]

The fuel injector has a Schrader valve on the on it where you would hook up a fuel gauge to.(see attached Pic) I think Mercruiser has the same Schrader valve as well. The problem is you need a 90 degree adapter. So, any fuel gauge would work you just need the adapter. A quick search on the web produced a few adapters and some low cost fuel gauges. FYI..This injector can be cleaned by removing the injector from the mount, hook up a 12 volt battery with a switch and spray with carburetor cleaner and compressed air until you get a good atomization.

Coolant Switch

 

[jmauld]

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.

Do you have any idea why mercruiser and Kohler did not do this in their design? Is there a safety issue/requirement that prevented it?

Edit: speaking with someone else, they think they did this to keep the fuel in the tank from heating up on an extended trip.