GC1705 loosing it's prime.

[thepumpguysc]

That cloth braided line WILL seep thru.. you can actually put pressure on it w/ an air hose & watch it..
SO if its leaking fuel.. its sucking air.. & a lot of times> it'll suck air & NOT leak fuel.. which makes it doubly hard to find.. and "trying" to tell someone that, is almost impossible for them to believe.. SO, the line doesn't get changed & they still have a problem..

I've got over 30 years under my belt doing fuel systems.. and only fuel systems.. its been a very good living.
They "basically" all work the same.. some have a mechanical or electric "helper pump"
{supply/lift pump} & some are gravity fed.. Some have an electric shut-off & some are pull cable..
Some pumps have their own camshafts & some are externally drivin, like yours..
These are questions that need to be asked before diagnosis can start..
BUT, the theory is still the same.. low pressure fuel, void of any air, needs to be at the inj. pump inlet.. weather its 1-3 psi[gravity} or 6-12psi{lift pump}

 

[doneill127]

Pumpguy your experience has been very helpful and I appreciate you sharing your knowledge. Yesterday I replaced all the braided hose with Gates. Started right up this morning so crossing my fingers that things are resolved. Biggest problem I had replacing the hoses was finding small screw type hose clamps to replace the spring clamps. Found some 11-13 mm fuel line clamps that seem pretty good

 

[atsah]

I'd like to thank you guys ! I've been having almost the exact same issues you've been experiencing but on a Mahindra Max which has a Mitsubishi SL3 motor. I started a thread in the Mahindra forum on a no start issue. No fuel to the injectors, found the stop solenoid wasn't working right, low voltage to the solenoid due to terminal corrosion. Fixed that and still kept losing its' prime. Like you checked the electric pump, seemed OK and once I got it running it was alright, a little rough under load and acceleration. So decided to drain the tank and see if there was any crud or pluggage. To drain it I hooked up some clear tygon tubing to the electric pump outlet and turned the key on. Wow, should have seen the air bubbles/foam coming out of the pump. Had to be some serious inleakage. Decided to change out all the cloth braided fuel line and spring clamps upstream of the electric pump with solid hose and worm clamps. Fired up first time with no injector bleeding. Real test will be to see if it starts tomorrow. But looks promising and it's not running rough under load.

So thanks again for all the lessons and knowledge on how everything supposed to work !

How did it start after sitting all night?

 

[doneill127]

Started first try no issues. Didn’t do anything that put a load on it. If it starts tomorrow and the rains holds off might try and get some mowing in. Thanks for asking

 

[atsah]

Started first try no issues. Didn’t do anything that put a load on it. If it starts tomorrow and the rains holds off might try and get some mowing in. Thanks for asking

Sounds like you may have had a small air leak in one of the lines you replaced or a bad clamp. Glad it started right away. These systems need to be tight so air isn't an issue, the problem is like this one I'm working on, the process of elimination takes a while. I try not to change multiple things at once, If I add a bunch of variables It's almost impossible to figure out what fixed the problem.

I troubleshot internal electronic circuits for a living for 30 years, so I know an invisible adversary can be a tough row to hoe.

 

[doneill127]

I agree with you on one change at a time. When I put the clear tubing on the electric pump discharge and saw the amount of bubbles in the fuel it was pretty clear that there was a large air leak and it had to be on the suction side of the pump. So replacing the braided fuel lines really was only making one change. There’s no more air in the discharge and it seems to have fixed things. If it ends up that it doesn’t solve it think I’ll throw in the towel and call the dealer.

 

[atsah]

I agree with you on one change at a time. When I put the clear tubing on the electric pump discharge and saw the amount of bubbles in the fuel it was pretty clear that there was a large air leak and it had to be on the suction side of the pump. So replacing the braided fuel lines really was only making one change. There’s no more air in the discharge and it seems to have fixed things. If it ends up that it doesn’t solve it think I’ll throw in the towel and call the dealer.

I hear ya, hope you’re all set. I really never thought I would be removing injectors on a tractor with 200 hours on the meter, my International 350 hasn’t needed a non maintenance part in the last 20 years and 3000 hours.

 

[atsah]

Mike (thepumpguy) checked out the injectors today, they all test good. Fuel lines/clamps and electric fuel pump are next..

When I first started working on this thing, I blead the fuel filter housing and when I did I moved the housing itself a little off Center, and the tractor seemed to start better that day, weird. Now that I know the problem is not on the motor I’m okay with that. What’s left isn’t rocket science just time and a little money.

 

[doneill127]

You might want to try the clear tygon tubing on the electric pump discharge. When I first tested the pump I thought it was working fine. Wasn’t until I put the tygon on that I saw how much air was getting sucked in. My pump runs when the key is turned on so I ran the tubing from the discharge into the open tank and turned on the key. Good luck

 

[atsah]

You might want to try the clear tygon tubing on the electric pump discharge. When I first tested the pump I thought it was working fine. Wasn’t until I put the tygon on that I saw how much air was getting sucked in. My pump runs when the key is turned on so I ran the tubing from the discharge into the open tank and turned on the key. Good luck

I'll try that before I start replacing lines. I'm going to get the left side deck off so I can access the pump, lines and filter but not until I get the injectors back and put the motor back together and run the tractor to make sure it starts the same as it did, in the process of dismantling and putting everything back together it's always possible I inadvertently moved, tightened or adjusted the culprit and it may act differently..