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Genie s-40 starts then stalls

polco

Member
Joined
Jan 28, 2015
Messages
6
Location
Michigan
I have a 1999 Genie s-40 425lrg [2.5 ] EFI motor, The last user put diesel fuel in the gas tank, about a 50/50 mix . I drained the gas tank and installed a new fuel filter and after a dozen tries it started. It smoked a little and I ran it at high speed and at idle for 5-6 minutes and then I shut it off. I replaced a leaking valve cover gasket and installed a new set of plugs while I had it apart, also oil and filter change and changed out the hyd. filter element.I tried to start it after that work and it would start up and run 2-3 seconds then shut right off . I replaced the MAF sensor and it would not even fire , put old sensor back on it and it would run 2-3 sec. and shut back off. I checked the relays , they are o.k.
I am not getting any codes from the machine. Any ideas ?
 

barklee

Senior Member
Joined
Aug 4, 2009
Messages
903
Location
ohio
I have a 1999 Genie s-40 425lrg [2.5 ] EFI motor, The last user put diesel fuel in the gas tank, about a 50/50 mix . I drained the gas tank and installed a new fuel filter and after a dozen tries it started. It smoked a little and I ran it at high speed and at idle for 5-6 minutes and then I shut it off. I replaced a leaking valve cover gasket and installed a new set of plugs while I had it apart, also oil and filter change and changed out the hyd. filter element.I tried to start it after that work and it would start up and run 2-3 seconds then shut right off . I replaced the MAF sensor and it would not even fire , put old sensor back on it and it would run 2-3 sec. and shut back off. I checked the relays , they are o.k.
I am not getting any codes from the machine. Any ideas ?

We had an oil pressure sensor do that. Also is the engine circuit breaker popping on the lower control panel?
 

polco

Member
Joined
Jan 28, 2015
Messages
6
Location
Michigan
The circuit breakers on the control panel are O.K. , I noticed that it had oil pressure the short time that it ran. I believe it has an oil pressure switch and a sending unit. I will check them out next, Thanks for the quick response !
 

polco

Member
Joined
Jan 28, 2015
Messages
6
Location
Michigan
I am still working on it . I replaced the oil pressure switch and it still does the same thing, runs 2-3 sec. and shuts back off. I took off the cam position sensor and having that checked out. Will let you know if that is the problem. Jon
 

polco

Member
Joined
Jan 28, 2015
Messages
6
Location
Michigan
I replaced the cam sensor but that was not the problem , still shuts off after 2-3 seconds. ????? I will find an electrical schematic for that and start tracing wires, maybe a shorted wire or open circuit?
 

Girth_Brooks

Member
Joined
Feb 22, 2021
Messages
20
Location
Scranton, PA
Occupation
Mechanic/Welder, Operator/Labor
We had an oil pressure sensor do that. Also is the engine circuit breaker popping on the lower control panel?
I have genie s40 that shuts off when high idle in load. And the engine fuse pops on lower panel
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
The Genie's will shut down after a few seconds if the system voltage is too high. Check and make sure it's not charging 18 volts or something as crazy.

And ah.....Welcome to the Forum
 

Txhayseed

Senior Member
Joined
Dec 23, 2019
Messages
610
Location
Texas
Its a ground seeking system. I wouldn't install any new parts. Did you purge the lines ???? Remove the return to tank line and jump the fuel pump to completely run the diesel mix out of lines, rail, injectors?? It takes awhile to push all the diesel out. The return rate on the engine is very minimal. Diesel does not combust like gas. If you have and diesel still in the system you will get a chuck and die. System can not light the mix.pull air filter out and spray some carb cleaner in and see if unit runs on carb cleaner. If you can keep it going with spritzing it with carb cleaner then its fuel related. We deal with this all the time in the rental business. Gas in diesel/ diesel in gas/ hydraulic fluid in diesel tank and so on. Try the carb cleaner and see how it runs.
 
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