Gehl 7810 cranks but won’t fire

[Warnec]

I have a Gehl 7810 at work that won’t start. A coworker was using it, shut it off to talk to someone and it wouldn’t start again. Things I’ve tested; oil pressure switch seems ok, crankshaft sensor reads 130 ohms, replaced lift pump, old one wasn’t pumping at all. Cracked open all the injector lines and have fuel to each one. I noticed the glow plugs don’t have power to them but it’s in a heated shop so I’m not worried about that right now. I can get it to pop off on either (don’t worry I’m barely spraying any in there). There is a solenoid of some sort on the bottom of the injection pump (Perkins # 2644N204 12v) when I hold my hand to it and someone turns the key on, I cannot feel it actuating. The only other thing I can think of is possibly the ecm, it had an issue when it was running that if you brought it down to an idle it was stuck on idle until you shut it down and let it sit for a while. If anyone has any ideas I’m open to suggestions. Thank you.

 

[BearCreekGravel]

Omg, I feel your pain. I have had my machine for almost 10 years and it seems like it goes to the dealer every winter. Trying to get the dead pig on a trailer is a whole ordeal. I’ve ran into new lift pumps that were garbage, the ecm needs to see like 4.5 psi minimum fuel pressure or it won’t start. A new one I put on would free flow fuel like crazy but wouldn’t build enough pressure. When you hit it with the can does it stay running and operate normally? Will it re-start again sometimes? The solenoid that you’re talking about on the bottom is controlled by the ecm I believe and needs to be satisfied with enough fuel pressure from lift pump. I’m seriously considering dumping mine, the machine is an absolute beast when everything is working. What year is it? I believe mine is an ‘05.

 

[Simon C]

I have a Gehl 7810 at work that won’t start. A coworker was using it, shut it off to talk to someone and it wouldn’t start again. Things I’ve tested; oil pressure switch seems ok, crankshaft sensor reads 130 ohms, replaced lift pump, old one wasn’t pumping at all. Cracked open all the injector lines and have fuel to each one. I noticed the glow plugs don’t have power to them but it’s in a heated shop so I’m not worried about that right now. I can get it to pop off on either (don’t worry I’m barely spraying any in there). There is a solenoid of some sort on the bottom of the injection pump (Perkins # 2644N204 12v) when I hold my hand to it and someone turns the key on, I cannot feel it actuating. The only other thing I can think of is possibly the ecm, it had an issue when it was running that if you brought it down to an idle it was stuck on idle until you shut it down and let it sit for a while. If anyone has any ideas I’m open to suggestions. Thank you.

Some motors with glow plugs will not start at all if they do not work, even in the summer. A good test for figuring out if the fuel system is the problem is to remove the air filter after first blowing the housing out while the filters are still in. Spray heavily WD40 into the air intake while shooting a heat gun in at the same time while cranking. Need two people to do obviously. If it fires up and runs you know you have a fuel problem. Can also try pushing air into the fuel tank with 1-2 psi of air with a variable trigger blow gun and the blow gun pipe into the tank. Use a rag ball to control the air pressure in the tank so you don't have a violent fuel shower. If someone else holds the air pressure on you can check for leaks at all the fittings, If the engine seems to run better with air pressure on you have a weak pump of some sort or restriction in the fuel system somewhere.
Few simple things to check along with banjo filters in the banjo bolts at fuel pump if it has some.
Simon C

 

[Simon C]

Omg, I feel your pain. I have had my machine for almost 10 years and it seems like it goes to the dealer every winter. Trying to get the dead pig on a trailer is a whole ordeal. I’ve ran into new lift pumps that were garbage, the ecm needs to see like 4.5 psi minimum fuel pressure or it won’t start. A new one I put on would free flow fuel like crazy but wouldn’t build enough pressure. When you hit it with the can does it stay running and operate normally? Will it re-start again sometimes? The solenoid that you’re talking about on the bottom is controlled by the ecm I believe and needs to be satisfied with enough fuel pressure from lift pump. I’m seriously considering dumping mine, the machine is an absolute beast when everything is working. What year is it? I believe mine is an ‘05.

A fuel filter with a load of water that just hit it will cause a pump to struggle to get sufficient pressure to give computers the okay to go.
Whole story here lately of Cat Loader that died and mechanic changed filter and it ran 45 seconds. Spent another 1.5 days testing all kinds of stuff to find out new filter was plugged again. About $2000 of labour and one filter later all running.
Guy needs to know there is sufficient fuel.
Simon C