Someone put gas in my diesel bobcat 643

[gladiator175]

Hey guys, uncle of mine ut gas in my 643 bobcat which has a Kubota D1402 engine. Engine stopped running. Removed fuel tank, empied all fuel, blow out all lines, since its the weekend can't get new fuel filter but tried to blow it out of the gas as best I could. Primed unit, with prime bulb these units have, fuel did do to the fuel filter since I can see it in the fuel filter glass. Can't get fuel to come out of bleed valve though....Is this necessary? Maybe I didn't pump prime bulb enough times. Anyways tried to start it again....no go. Anyone have any suggestions? I'm going to remove and test glow plugs this am see if they are ok.

 

[OldMachinist]

You likly just need to prime it a bit more. If this is the first time this has happened it shouldn't have done any damage to anything. Prolonged used of gas in a diesel can damage the injectors and pump because they depend on the diesel fuel for lubrication. You can give it a shot of WD 40 in the intake as starting fluid and it may run enough to flush the rest of the gas out of the injector lines.
If your going to loan it out again I'd buy some labels that say diesel fuel only to put near the fill port.

 

[gladiator175]

You likly just need to prime it a bit more. If this is the first time this has happened it shouldn't have done any damage to anything. Prolonged used of gas in a diesel can damage the injectors and pump because they depend on the diesel fuel for lubrication. You can give it a shot of WD 40 in the intake as starting fluid and it may run enough to flush the rest of the gas out of the injector lines.
If your going to loan it out again I'd buy some labels that say diesel fuel only to put near the fill port.

How would you install a pressure gage to check the head pressure on this? Meaning where on the engine?

 

[Fishfiles]

How would you install a pressure gage to check the head pressure on this? Meaning where on the engine?

Did you bleed the injectors to purge all the gas from the lines , also you could try to either hook an external can of fuel to the primer bulb or by pass the filter housing as you may have a air leak on the filter assembly , those glass bowl filters were bad for that , there is an adaptor available to switch it over to a spin on , or the head can be changed so that it accepts a spin on , I never was a fan of the glass bowl Perkins style filter assembly ------gas in the fuel I found causes a bunch of different results depending on the percentage of the mix , too much gas can but not always make it run away , the right mix and it will run but bad , and other mix and it will not run at all , it may not start because of compression , and easy test if you don't have the adaptor or gauge to test it is to remove all the glow plugs and put a figer over each hole and spin it , you will know if a cyclinder is dead or limb

 

[gladiator175]

Did you bleed the injectors to purge all the gas from the lines , also you could try to either hook an external can of fuel to the primer bulb or by pass the filter housing as you may have a air leak on the filter assembly , those glass bowl filters were bad for that , there is an adaptor available to switch it over to a spin on , or the head can be changed so that it accepts a spin on , I never was a fan of the glass bowl Perkins style filter assembly ------gas in the fuel I found causes a bunch of different results depending on the percentage of the mix , too much gas can but not always make it run away , the right mix and it will run but bad , and other mix and it will not run at all , it may not start because of compression , and easy test if you don't have the adaptor or gauge to test it is to remove all the glow plugs and put a figer over each hole and spin it , you will know if a cyclinder is dead or limb

Spin the engine using starter I assume? As I can't spin it by hand

 

[gladiator175]

Did you bleed the injectors to purge all the gas from the lines , also you could try to either hook an external can of fuel to the primer bulb or by pass the filter housing as you may have a air leak on the filter assembly , those glass bowl filters were bad for that , there is an adaptor available to switch it over to a spin on , or the head can be changed so that it accepts a spin on , I never was a fan of the glass bowl Perkins style filter assembly ------gas in the fuel I found causes a bunch of different results depending on the percentage of the mix , too much gas can but not always make it run away , the right mix and it will run but bad , and other mix and it will not run at all , it may not start because of compression , and easy test if you don't have the adaptor or gauge to test it is to remove all the glow plugs and put a figer over each hole and spin it , you will know if a cyclinder is dead or limb

Also I take it you mean I not only have to crack the bleed valve on the injector pump, I had to crack each injectors nut?

 

[gladiator175]

Also I take it you mean I not only have to crack the bleed valve on the injector pump, I had to crack each injectors nut?

Hey fishfiles...where would you hook up a compression tester? I'll send also some picts tonight

 

[Fishfiles]

Hey fishfiles...where would you hook up a compression tester? I'll send also some picts tonight

Yes spin the motor over with the starter , after you crank open all the ferraled tubing nuts on top of the injectors and have someone else spin it over so you can see the fuel coming out , you can hook up a starter remote switch or even use a screwdriver at the starter solinod but thats primative and can screw up the threads on the stud on the solinoid from aching , let the fuel flow for about 30 seconds out the injectors then close them it should fire up , if not do it again , I will close one at a time as it is spinning and by 3 closed it is usually running ----------the compression is easier tested thru the glow plug holes , if not adaptor is available and you have an old glow plug you can make one if you can weld a fitting to the top of an old glow plug which you cut with a saw or grinder then drive the guts out of it with a punch while in a vise , the compression should be like 450- 475 , and all within 10% of one another , I have learned to feel it with my finger pretty good and can see a problem alot of time without a gauge hooked up , as if one cyclinder wouldn't even pop your finger and others will blow it off

 

[Tazza]

Yes spin the motor over with the starter , after you crank open all the ferraled tubing nuts on top of the injectors and have someone else spin it over so you can see the fuel coming out , you can hook up a starter remote switch or even use a screwdriver at the starter solinod but thats primative and can screw up the threads on the stud on the solinoid from aching , let the fuel flow for about 30 seconds out the injectors then close them it should fire up , if not do it again , I will close one at a time as it is spinning and by 3 closed it is usually running ----------the compression is easier tested thru the glow plug holes , if not adaptor is available and you have an old glow plug you can make one if you can weld a fitting to the top of an old glow plug which you cut with a saw or grinder then drive the guts out of it with a punch while in a vise , the compression should be like 450- 475 , and all within 10% of one another , I have learned to feel it with my finger pretty good and can see a problem alot of time without a gauge hooked up , as if one cyclinder wouldn't even pop your finger and others will blow it off

It sounds like you haven't purged all the air yet. I have never found cracking the high pressure lines at the injectors to be needed. Open the bleed screw on the engine, pump the hand primer till it feels firm as you squeeze fuel through. You can feel the air, small vibrations from air bubbles. When its smooth, close the bleed screw and crank the engine. It may start then die, or run rough till fuel reaches ALL injectors. Number one will start first as the line is shorter than the others. Crank it with the starter, not by hand too, it won't cause any damage. Just don't keep cranking for longer than 30 second blocks. You will need to let the starter cool off. It shouldnt' take more than 30 seconds to get it to start anyway.
Good luck, get the air out and you'll be good to go.

 

[Fishfiles]

It sounds like you haven't purged all the air yet. I have never found cracking the high pressure lines at the injectors to be needed. Open the bleed screw on the engine, pump the hand primer till it feels firm as you squeeze fuel through. You can feel the air, small vibrations from air bubbles. When its smooth, close the bleed screw and crank the engine. It may start then die, or run rough till fuel reaches ALL injectors. Number one will start first as the line is shorter than the others. Crank it with the starter, not by hand too, it won't cause any damage. Just don't keep cranking for longer than 30 second blocks. You will need to let the starter cool off. It shouldnt' take more than 30 seconds to get it to start anyway.
Good luck, get the air out and you'll be good to go.

I don't think you read all his post Taaza , what about if he had gas put into the fuel tank , it quite running and won't start , I think he needs to bleed the injector tubes to get the gas /diesel mix out of the injection system and fresh fuel in

 

[Tazza]

I don't think you read all his post Taaza , what about if he had gas put into the fuel tank , it quite running and won't start , I think he needs to bleed the injector tubes to get the gas /diesel mix out of the injection system and fresh fuel in

whoops, didn't think about that.... My bad
One thing, if you do a compression test through a glow plug port, ensure you shut the fuel off, i assume it uses a stop cable. If it fires while testing the compression, it will destroy your pressure tester.

 

[Fishfiles]

whoops, didn't think about that.... My bad
One thing, if you do a compression test through a glow plug port, ensure you shut the fuel off, i assume it uses a stop cable. If it fires while testing the compression, it will destroy your pressure tester.

always take all the glow plugs out when doing a compression test so there is no chance of it starting and get a more accurate test , a blow head gasket can let compression flow between cylinders