You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Export thread
Command Pro CV26 EFI fuel issue
#1
T
Toolz
T
Toolz
Bought this Husqvarna ZTH6126 a couple of weeks ago, seller said the engine was locked up. Turned out to be a seized PTO clutch bearing. Replaced the clutch, and it fired right up. Thought it was my lucky day. Mowed about 15-20 minutes, and the engine started to sputter, then died. Obvious fuel issue, and apparently heat related. Let it cool a few minutes, and off we go again, for 10-15 minutes, then repeat. Got out the fuel pressure gauge, hooked it up, let the engine cool, and tried again. Fuel pressure at 39 psi. Started mowing again, and after 10 minutes, pressure started to fall off gradually, down to 12 psi, and the engine died. Pinched off the fuel return line to dead head the pump, and no rise in pressure. From my automotive experience, I thought I had a bad pump. New pump arrived today. Installed it, and headed out to mow. 15 minutes in, same problem! Fuel pressure tapered off again, and no fuel returning to the tank. Let it cool a few minutes, and we have flow through the return again. I don't now what else to check. It has the problem on either fuel tank. I let it run for nearly an hour this evening at a high idle with no issues, but as soon as it's under load mowing for 10-15 minutes, it dies again. Must be heat related, but I don't have a clue how. Any help would be greatly appreciated.
#2
B
bertsmobile1
B
bertsmobile1
Mowers run in a lot more dust than cars and get filled from cans .
Debris builds up in the tank and blocks off the outlet like hairs getting drawn into the shower drain.
In order for fuel to get out of the tank, fuel has to get in so there is a vent in the tank cap, or a vent line from the carb to the tank ( EPA Strikes again ).
So first test is simply undo the cap and listen for the suck then try to start it.
Second test is to pull the fuel line off the pump side and blow back up the line & try again, engine fire right up then take the tank out & clean it + replace all of the fuel lines.
No joy there then get a spark tester and check if you have spark immediately after the engine dies.
After that you are looking at temperature / oil level problems.
Kohler have the manual for your engine available on line as free download.
Debris builds up in the tank and blocks off the outlet like hairs getting drawn into the shower drain.
In order for fuel to get out of the tank, fuel has to get in so there is a vent in the tank cap, or a vent line from the carb to the tank ( EPA Strikes again ).
So first test is simply undo the cap and listen for the suck then try to start it.
Second test is to pull the fuel line off the pump side and blow back up the line & try again, engine fire right up then take the tank out & clean it + replace all of the fuel lines.
No joy there then get a spark tester and check if you have spark immediately after the engine dies.
After that you are looking at temperature / oil level problems.
Kohler have the manual for your engine available on line as free download.
#3
T
Toolz
This mower has two tanks, both squeaky clean when I got it, and the problem happens with either tank, in the same time frame. When the problem occurs, I can remove the tank cap, and there is no fuel returning. I did clean the vents anyway. This is not a spark issue. Fuel pressure is dropping. Oil is full and clean, and there are no trouble codes indicated. Engine temperature seems fine, but even if it isn't, fuel should continue to flow through the system. Thanks for taking the time to reply!
T
Toolz
Mowers run in a lot more dust than cars and get filled from cans .
Debris builds up in the tank and blocks off the outlet like hairs getting drawn into the shower drain.
In order for fuel to get out of the tank, fuel has to get in so there is a vent in the tank cap, or a vent line from the carb to the tank ( EPA Strikes again ).
So first test is simply undo the cap and listen for the suck then try to start it.
Second test is to pull the fuel line off the pump side and blow back up the line & try again, engine fire right up then take the tank out & clean it + replace all of the fuel lines.
No joy there then get a spark tester and check if you have spark immediately after the engine dies.
After that you are looking at temperature / oil level problems.
Kohler have the manual for your engine available on line as free download.
This mower has two tanks, both squeaky clean when I got it, and the problem happens with either tank, in the same time frame. When the problem occurs, I can remove the tank cap, and there is no fuel returning. I did clean the vents anyway. This is not a spark issue. Fuel pressure is dropping. Oil is full and clean, and there are no trouble codes indicated. Engine temperature seems fine, but even if it isn't, fuel should continue to flow through the system. Thanks for taking the time to reply!
#4
B
bertsmobile1
B
bertsmobile1
Try the tap.
Not sure if these have a lift & pressure pump or just a pressure pump.
The other trick I use regularly is to hook up a temporary fuel line from spare tank.
If I can lay my hands on it the 1 gal tecumseh tank other wise it is a 1 qt tank from a push mower that I quickly swap over when the mower dies.
I have come across this problem countless times.
Occasionally I have resorted to hooking the fuel line up to a vacuum pump.
A lot of tanks are made with moulds that have the outlet in both sides so you get a moulding flash along the outlet tube , inside the tube.
The 2000 series Cubs are notorious for it down here.
Could not count all the people who have replaced a perfectly good mechanical pump $$$$ then magnetos and finally given up & brought it in.
The fact that you are getting no error messages point to a fuel line blockage.
I presume you have checked the valve in the return line .
Not sure if these have a lift & pressure pump or just a pressure pump.
The other trick I use regularly is to hook up a temporary fuel line from spare tank.
If I can lay my hands on it the 1 gal tecumseh tank other wise it is a 1 qt tank from a push mower that I quickly swap over when the mower dies.
I have come across this problem countless times.
Occasionally I have resorted to hooking the fuel line up to a vacuum pump.
A lot of tanks are made with moulds that have the outlet in both sides so you get a moulding flash along the outlet tube , inside the tube.
The 2000 series Cubs are notorious for it down here.
Could not count all the people who have replaced a perfectly good mechanical pump $$$$ then magnetos and finally given up & brought it in.
The fact that you are getting no error messages point to a fuel line blockage.
I presume you have checked the valve in the return line .
#5
ILENGINE
ILENGINE
The EFI Kohler has both a mechanical or vacuum operated pump and a electric high pressure injection pump. Which pump did you replace. Also make sure you have the correct fuel filter system, since Kohler has has issues with the incorrect fuel filter being using allowing debris to enter and block the internal filter on the injection pump.
#6
T
Toolz
This unit has no vacuum operated pump, only the high pressure pump, which I replaced. Lines lead from each tank to a switching valve, and then to the high pressure pump. It had the wrong filter on the high pressure side when I got it (plastic!), and I replaced it with the proper Kohler part number. There is a small filter in each feed line before the switching valve. They are both clean and clear. Very good fuel flow from either tank when cool.
T
Toolz
The EFI Kohler has both a mechanical or vacuum operated pump and a electric high pressure injection pump. Which pump did you replace. Also make sure you have the correct fuel filter system, since Kohler has has issues with the incorrect fuel filter being using allowing debris to enter and block the internal filter on the injection pump.
This unit has no vacuum operated pump, only the high pressure pump, which I replaced. Lines lead from each tank to a switching valve, and then to the high pressure pump. It had the wrong filter on the high pressure side when I got it (plastic!), and I replaced it with the proper Kohler part number. There is a small filter in each feed line before the switching valve. They are both clean and clear. Very good fuel flow from either tank when cool.
#7
B
bertsmobile1
B
bertsmobile1
So the only parts in the fuel system is
1) filter 2405006S
2) the electric pump 2439352S
3) the fuel regulator 2440316S
4) The manifold & injectors
5) the tank switch
6) the fuel tanks.
To date you have replaced 1 & 2
So I would still recommend plugging in an auxillary tank, higher than the pump so it has a head on it.
This will knock out 5 & 6 which will leave you with the regulator .
IF here is not enough fuel getting to the pump then the pump will not be able to make pressure.
If the fuel is boiling in the lines the pump will not be able to get to working pressure.
1) filter 2405006S
2) the electric pump 2439352S
3) the fuel regulator 2440316S
4) The manifold & injectors
5) the tank switch
6) the fuel tanks.
To date you have replaced 1 & 2
So I would still recommend plugging in an auxillary tank, higher than the pump so it has a head on it.
This will knock out 5 & 6 which will leave you with the regulator .
IF here is not enough fuel getting to the pump then the pump will not be able to make pressure.
If the fuel is boiling in the lines the pump will not be able to get to working pressure.
#8
T
Toolz
There are no tank problems. The regulator is not the issue, since I can block it off to dead-head the pump with no change in pressure. I did finally find one reference on line to vapor lock ahead of the pump, which is the only possibility at this point. I am eliminating this problem by installing a low pressure lift pump under each tank, with a toggle to switch them when I select which tank to run on. The more extreme solution would be to install an EFI pump under each tank, but I'll try this first. Still makes no sense that this problem presents itself after 1100 hours. Maybe premium fuel with a lower vaporization rate would help, but I've read no recommendations for this.
T
Toolz
So the only parts in the fuel system is
1) filter 2405006S
2) the electric pump 2439352S
3) the fuel regulator 2440316S
4) The manifold & injectors
5) the tank switch
6) the fuel tanks.
To date you have replaced 1 & 2
So I would still recommend plugging in an auxillary tank, higher than the pump so it has a head on it.
This will knock out 5 & 6 which will leave you with the regulator .
IF here is not enough fuel getting to the pump then the pump will not be able to make pressure.
If the fuel is boiling in the lines the pump will not be able to get to working pressure.
There are no tank problems. The regulator is not the issue, since I can block it off to dead-head the pump with no change in pressure. I did finally find one reference on line to vapor lock ahead of the pump, which is the only possibility at this point. I am eliminating this problem by installing a low pressure lift pump under each tank, with a toggle to switch them when I select which tank to run on. The more extreme solution would be to install an EFI pump under each tank, but I'll try this first. Still makes no sense that this problem presents itself after 1100 hours. Maybe premium fuel with a lower vaporization rate would help, but I've read no recommendations for this.
#9
E
edhead
I'd love to hear how this ended. Did you identify the problem? I am having an almost identical problem, and its driving me nuts. My fuel pressure drops to 9-12psi when it looses power. Up around 39 or so it runs great. In my case, its a zero turn mower with a single tank...electric pump replaced, as well as fuel cap, fuel pressure regulator, all lines, the stank siphon and return tubes, and oxygen sensor.
THanks.
E
edhead
There are no tank problems. The regulator is not the issue, since I can block it off to dead-head the pump with no change in pressure. I did finally find one reference on line to vapor lock ahead of the pump, which is the only possibility at this point. I am eliminating this problem by installing a low pressure lift pump under each tank, with a toggle to switch them when I select which tank to run on. The more extreme solution would be to install an EFI pump under each tank, but I'll try this first. Still makes no sense that this problem presents itself after 1100 hours. Maybe premium fuel with a lower vaporization rate would help, but I've read no recommendations for this.
I'd love to hear how this ended. Did you identify the problem? I am having an almost identical problem, and its driving me nuts. My fuel pressure drops to 9-12psi when it looses power. Up around 39 or so it runs great. In my case, its a zero turn mower with a single tank...electric pump replaced, as well as fuel cap, fuel pressure regulator, all lines, the stank siphon and return tubes, and oxygen sensor.
THanks.
#10
BlazNT
Hook up a voltage gage and see what is happening when you lose power.
BlazNT
I'd love to hear how this ended. Did you identify the problem? I am having an almost identical problem, and its driving me nuts. My fuel pressure drops to 9-12psi when it looses power. Up around 39 or so it runs great. In my case, its a zero turn mower with a single tank...electric pump replaced, as well as fuel cap, fuel pressure regulator, all lines, the stank siphon and return tubes, and oxygen sensor.
THanks.
Hook up a voltage gage and see what is happening when you lose power.
#11
E
edhead
Voltage gauge? Connected to what specifically?
Thank you for your response BlazNT.....
E
edhead
Hook up a voltage gage and see what is happening when you lose power.
Voltage gauge? Connected to what specifically?
Thank you for your response BlazNT.....
#12
BlazNT
BlazNT
Sorry for my wording. Something like this connected to battery. It will let you know what your voltage is running. I think it may be dropping out.
https://www.amazon.com/Waterproof-C...3639799&sr=8-6&keywords=amp+meter+usb+charger
https://www.amazon.com/Waterproof-C...3639799&sr=8-6&keywords=amp+meter+usb+charger
#13
Boudreaux In Eunice La.
Boudreaux In Eunice La.
I agree with Blaze on the voltage........ The electric clutch is using voltage the whole time the blades are in use and the electric pump is using voltage also .... The alternator is not keeping up more than likely..... A bad connection at the connector from the ALT or a bad battery if the ALT is working right ..........
That's my 25 cent piece since 2 cents ain't worth nothing anymore............
Let Us know Mon Ami ~!~!
That's my 25 cent piece since 2 cents ain't worth nothing anymore............
Let Us know Mon Ami ~!~!
#14
E
edhead
Thanks again BlazNT, I ordered it this morning and I'll let you know what I find in a few days.
E
edhead
Sorry for my wording. Something like this connected to battery. It will let you know what your voltage is running. I think it may be dropping out.
https://www.amazon.com/Waterproof-C...3639799&sr=8-6&keywords=amp+meter+usb+charger
Thanks again BlazNT, I ordered it this morning and I'll let you know what I find in a few days.
#15
E
edhead
Thanks Boudreaux!
E
edhead
I agree with Blaze on the voltage........ The electric clutch is using voltage the whole time the blades are in use and the electric pump is using voltage also .... The alternator is not keeping up more than likely..... A bad connection at the connector from the ALT or a bad battery if the ALT is working right ..........
That's my 25 cent piece since 2 cents ain't worth nothing anymore............
Let Us know Mon Ami ~!~!
Thanks Boudreaux!