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Diesel pump timing tool
- Thread starter cathead
- Start date
- Joined
- Feb 7, 2013
- Messages
- 2,555
The temperature here is currently -28F or -34C but at least no wind outside. I took a walk in
the early dawn down the 1/4 mile trail in pretty deep snow to take a photo or two of the Petter TW2.
It was a bit frosty I must say and I kept the camera in my inside parka jacket pocket so it would
function when I got there.
In the middle of the photo is the oiler system(yellow part) that feeds oil to all the bearings and cylinders.
I have had it running a few times but not on a day like today...
the early dawn down the 1/4 mile trail in pretty deep snow to take a photo or two of the Petter TW2.
It was a bit frosty I must say and I kept the camera in my inside parka jacket pocket so it would
function when I got there.
In the middle of the photo is the oiler system(yellow part) that feeds oil to all the bearings and cylinders.
I have had it running a few times but not on a day like today...
Attachments
- Joined
- Feb 7, 2013
- Messages
- 2,555
Regarding the timing on the Isuzu 4jb1 with Zexel injection pump:
Finally, I got around to tearing into the Bobcat engine to use my home made timing tool. That was quite uneventful
and the timing is set properly now but am still having starting problems. Not willing to give up, I decided to get the best injector
cleaner I could find and try that. The stuff is called Diesel Extreme. I set the quart bottle on the ground behind the skid steer
and attached a hose directly into the bottle so the engine would be running on pure injector cleaner. It started easily with
a few cc of gasoline into the air cleaner to get it running. Interestingly, the quart bottle was half gone in about two minutes of
run time. The return line from the injectors was putting the injector cleaner back into the fuel tank I reckon. So that's where
I was supposed to put the stuff in the first place! So at that point, I reconnected up the fuel system and moved some dirt
for an hour or so and it quit smoking pretty much and seemed to run somewhat better but still would not crank start.....grrrrr
So now for the next phase of my diagnosis work. The machine just turned over 3000 hours so the injectors could be
tired I surmised. Looking on the internet, I see Isuzu injectors sell for 300+ dollars apiece and some aftermarket ones
are available for a set of four for under a hundred dollars. I did attempt to remove one injector and with everything
disconnected, It didn't want to come out of the hole so heed help on that subject. The idea was to remove one injector
and connect it up so I could see the spray pattern or lack thereof but didn't get that far yesterday. I did crank over
the engine and there is output from the pump. There is no smoke just cranking the engine so have to think it is either
low pump pressure or injectors lacking to function at low speeds. It becomes more challenging without a complete
set of tools and gauges. Then you think of how many million times the injector has pumped fuel into the cylinder,
it's not surprising to me that the injectors might need repair or replacement. I know there are shims that are
used to set the output pressure but one needs a lot of diagnostic tools to do that kind of work.
Once I can figure out how to remove the injectors, I'm tempted to buy an aftermarket set for a hundred
dollars and see what happens. They seem stuck in the hole probably crudded up with carbon and dirt
so looking to find out how to get them out. Of course one removes the injector line, the return line and
the bolt that holds down the two fingered clamp that holds the injector in place. There are a couple of
flats on the top of the injector so maybe a twist with a wrench would break them loose.
So that's my story. Thanks for reading along. I'm open to any advice y'all might have. It's not going to give up
and take it to the Bobcat dealer as my intent is to fix it myself and learn a lot in the process, maybe even buy a
few more tools to add to my collection.
Finally, I got around to tearing into the Bobcat engine to use my home made timing tool. That was quite uneventful
and the timing is set properly now but am still having starting problems. Not willing to give up, I decided to get the best injector
cleaner I could find and try that. The stuff is called Diesel Extreme. I set the quart bottle on the ground behind the skid steer
and attached a hose directly into the bottle so the engine would be running on pure injector cleaner. It started easily with
a few cc of gasoline into the air cleaner to get it running. Interestingly, the quart bottle was half gone in about two minutes of
run time. The return line from the injectors was putting the injector cleaner back into the fuel tank I reckon. So that's where
I was supposed to put the stuff in the first place! So at that point, I reconnected up the fuel system and moved some dirt
for an hour or so and it quit smoking pretty much and seemed to run somewhat better but still would not crank start.....grrrrr
So now for the next phase of my diagnosis work. The machine just turned over 3000 hours so the injectors could be
tired I surmised. Looking on the internet, I see Isuzu injectors sell for 300+ dollars apiece and some aftermarket ones
are available for a set of four for under a hundred dollars. I did attempt to remove one injector and with everything
disconnected, It didn't want to come out of the hole so heed help on that subject. The idea was to remove one injector
and connect it up so I could see the spray pattern or lack thereof but didn't get that far yesterday. I did crank over
the engine and there is output from the pump. There is no smoke just cranking the engine so have to think it is either
low pump pressure or injectors lacking to function at low speeds. It becomes more challenging without a complete
set of tools and gauges. Then you think of how many million times the injector has pumped fuel into the cylinder,
it's not surprising to me that the injectors might need repair or replacement. I know there are shims that are
used to set the output pressure but one needs a lot of diagnostic tools to do that kind of work.
Once I can figure out how to remove the injectors, I'm tempted to buy an aftermarket set for a hundred
dollars and see what happens. They seem stuck in the hole probably crudded up with carbon and dirt
so looking to find out how to get them out. Of course one removes the injector line, the return line and
the bolt that holds down the two fingered clamp that holds the injector in place. There are a couple of
flats on the top of the injector so maybe a twist with a wrench would break them loose.
So that's my story. Thanks for reading along. I'm open to any advice y'all might have. It's not going to give up
and take it to the Bobcat dealer as my intent is to fix it myself and learn a lot in the process, maybe even buy a
few more tools to add to my collection.
- Joined
- Feb 2, 2013
- Messages
- 4,133
Nozzles often become clogged
Does it have the bosch type of injectors?
3000 hours is very low for many diesels.
just breaking in, for some brands .
my uncle had the same symptoms on his bobcat, come to find out that the primer pump o-rings were worn and subsequently somehow pumped air into the fuel pump.
After bypassing the primer pump and bleeding the injectors, i was able to get Bessie to fire off.
Not saying that you have the same problem, but the introduction even small amounts of air into the fuel system causes issues . It may be worthy of investigation.
Does it have the bosch type of injectors?
3000 hours is very low for many diesels.
just breaking in, for some brands .
my uncle had the same symptoms on his bobcat, come to find out that the primer pump o-rings were worn and subsequently somehow pumped air into the fuel pump.
After bypassing the primer pump and bleeding the injectors, i was able to get Bessie to fire off.
Not saying that you have the same problem, but the introduction even small amounts of air into the fuel system causes issues . It may be worthy of investigation.
- Joined
- Feb 7, 2013
- Messages
- 2,555
Mike,
Well, it has a Zexel VE pump that I think is made by Bosch so would expect it has Bosch injectors but don't know for sure. The
lines have been carefully looked over and tightened. There is no air in the return line going back to the fuel tank so have pretty
much ruled out some kind of low pressure side leak. It's beginning to look like the injectors are worn probably due to the
properties of ULSD which is an acronym for ultra low sulfur diesel. Removing the sulfur is a bad thing for injectors as the
sulfur adds lubricity. Without the sulfur, the injectors wear out faster from what I have been reading. Around here, the diesel
also contains 5% biodiesel which I would guess to be soybean and or corn oil.
I don't have an external primer pump on this machine.
This is a photo of what the injector looks like. I'm still waiting to order injectors until I have the old one out and can get some part
numbers from it .
- Joined
- Dec 15, 2018
- Messages
- 818
I add a couple of ounces of 2 stroke motor oil to 5 gallons of diesel in all my small engines. The tractor will give an awful knock when it fires up cold, expect an injector leaking down. With the oil added it never does it.
Greg
Greg
- Joined
- Feb 7, 2013
- Messages
- 2,555
Finally I got one of the injectors out and disassembled. I connected it to the line after cleaning so I could see
the spray pattern. Well, it didn't spray at all, more kind of a dribble. I did add a thin washer to the spring to see what would
happen and there was no flow at all discernible. So without a pressure tester or maybe an injector tester, I have to think
that the pump has low pressure on cranking. This is a bit of a quandary so not sure where it leads. Once the engine is running,
it works fine so am thinking the pump is the culprit for now.
the spray pattern. Well, it didn't spray at all, more kind of a dribble. I did add a thin washer to the spring to see what would
happen and there was no flow at all discernible. So without a pressure tester or maybe an injector tester, I have to think
that the pump has low pressure on cranking. This is a bit of a quandary so not sure where it leads. Once the engine is running,
it works fine so am thinking the pump is the culprit for now.
Last edited:
- Joined
- Sep 2, 2013
- Messages
- 5,458
I bought a new IH backhoe in 1980 that started having hard start issues a few months after purchase. It was under warranty, and the dealer mechanics went through it 4-5 times and gave up. I finally found a hairline crack under the nut at the feed line going into the high pressure pump. Might be worth a look. Mike