4jb1 guru needed

[mike11]

Ok guys the story, I have an 853 which was supposed to have had the engine rebuilt by the previous owner, it does show evidence of that, but also of Neanderthals working on the machine, if they were the ones who only installed it who knows. Machine is sometimes hard to start and doesn’t idle great . Has all new fuel filters, new pickup in the tank and line, new primer bulb and check valve in the fuel line. I replaced all 4 injectors with no change,compression is 375 on all 4 cylinders.

So at this point I narrowed it down to either pump timing or a pump. I bought the special tool to set the pump timing. This is where things get interesting. According to the bobcat manual for this machine for this serial #
Bring to tdc, Rock back 40ish degrees, put tool in pump rock engine back n forth make sure it’s at 0 and not moving. Then bring engine to 17* btdc and set pump at .020-.022 lift on the dial indicator. When I’ve done this it will not start only puffs white smoke, runs best with pump fully advanced and it seems like it would like more but the pump adjustment is maxed out. So I pulled the front cover to verify timing marks, redid all of it since j could not confirm how they were they’re only accurate till it’s rotated. Again the pump is not where it should be when the dial indicator is at 22 lift.
To get it to run again the pump was fully rocked outward advancing the timing, runs decent,starts decent ect but I like things correct.
This is acting like it’s a tooth off but all marks line up as they should.
Am I missing something with the line up procedure or use of the tool ?? What’s concerning is the pumps gotta be at its max swing to run decent and I think it’ll take more.
Any insight is much appreciated

Thanks

 

[foton]

I know nothing about the duetz really ,but is it possible that when the pump was installed on the gear that if it is keyed the key is bent ( some are made that way to get extra movement of time) or if not keyed as a friction fit it is off some, that way it would look like it is time but not.

 

[mike11]

I know nothing about the duetz really ,but is it possible that when the pump was installed on the gear that if it is keyed the key is bent ( some are made that way to get extra movement of time) or if not keyed as a friction fit it is off some, that way it would look like it is time but not.

Pump is keted
That’s all normal as it should be. This thing acts like it’s 1 tooth off.. really makes no sense.

 

[FJRDarksider]

If it was rebuilt then it may be a tooth out. I honestly don't know if the engine will run that way or not though.

I had the seals on my diesel pump start leaking so I removed it for rebuild but didn't note the timing mark "V" on the gear before I reinstalled and it wouldn't start.

Needless to say I removed the harmonic balancer and timing cover to see all of the gears. What I ended up doing was aligning the "X" and "Y" on the crank and cam gears (with the center idler gear), and then slipped off the idler gear between the pump so I could align the gear marks "Z" and "V" on that side. Worked like a charm and started right up, then I just adjusted the pump position by hand to where it sounded the smoothest. Since you have the tool that would be more accurate I imagine.

 

[FJRDarksider]

 

[mike11]

View attachment 10801

That’s exactly how it is right now, the strange thing is it acts like the pumps off a tooth. When the timing is set per manual instructions and with the special too it won’t start, just puffs white smoke. For it to run the pump needs full advance. When it’s in that position it could prob take more but it’s out of adjustment. I should be able to go past the sweet spot in either direction with pump swing. Pump seems to be retarded by 1 tooth. But the marks don’t show evidence of that. Pump shaft and key is all ok and intact.. it’s very strange. It runs decent how it is, I’d like it perfect how it should be since it was recently rebuilt I should be able to get it there, however I don’t know how long I’m gonna chase this one with it having to come apart for every change and verification.
When checking it with the dial indicator that shows it way off. It’s a head scratcher.

 

[foton]

I am wondering that when the engine was rebuilt that they did some work on the pump and got it assembled wrong, If you have a diesel pump rebuilder why not call them and pick their brains. Or take them pump to them and have that verifyed the assembly is correct or not. it seems to me that would narrow down what is wrong instead of guessing and head scratching. Sometimes we have to let the people that deal with this daily take a charge.

 

[FJRDarksider]

Perhaps the pump was rebuilt and bolted to the gear incorrectly? Seems like a stretch but all I can say is the pump is chock full of parts. I found a video online of a guy reassembling one that helped me put mine back together when i replaced the seals. I made the mistake initially of thinking I could do it while it was installed.......but the parts inside had other plans when I did that LOL. Maybe just needs a good cleaning including the lines and injectors?

 

[Firefighter]

Ok guys the story, I have an 853 which was supposed to have had the engine rebuilt by the previous owner, it does show evidence of that, but also of Neanderthals working on the machine, if they were the ones who only installed it who knows. Machine is sometimes hard to start and doesn’t idle great . Has all new fuel filters, new pickup in the tank and line, new primer bulb and check valve in the fuel line. I replaced all 4 injectors with no change,compression is 375 on all 4 cylinders.

So at this point I narrowed it down to either pump timing or a pump. I bought the special tool to set the pump timing. This is where things get interesting. According to the bobcat manual for this machine for this serial #
Bring to tdc, Rock back 40ish degrees, put tool in pump rock engine back n forth make sure it’s at 0 and not moving. Then bring engine to 17* btdc and set pump at .020-.022 lift on the dial indicator. When I’ve done this it will not start only puffs white smoke, runs best with pump fully advanced and it seems like it would like more but the pump adjustment is maxed out. So I pulled the front cover to verify timing marks, redid all of it since j could not confirm how they were they’re only accurate till it’s rotated. Again the pump is not where it should be when the dial indicator is at 22 lift.
To get it to run again the pump was fully rocked outward advancing the timing, runs decent,starts decent ect but I like things correct.
This is acting like it’s a tooth off but all marks line up as they should.
Am I missing something with the line up procedure or use of the tool ?? What’s concerning is the pumps gotta be at its max swing to run decent and I think it’ll take more.
Any insight is much appreciated

Thanks

Compression for that engine should be at 440 psi the service manual does not state what is minimum allowable limit. i would check the valves also, making sure the clearance is correct. i have adjusted timing to how it runs at full throttle, if the timing is retarded to much u will have a flutter & a blue haze at full rpm, meaning it needs advanced to where it sounds good with no smoke.

 

[mike11]

Compression for that engine should be at 440 psi the service manual does not state what is minimum allowable limit. i would check the valves also, making sure the clearance is correct. i have adjusted timing to how it runs at full throttle, if the timing is retarded to much u will have a flutter & a blue haze at full rpm, meaning it needs advanced to where it sounds good with no smoke.

Valaves have plenty of lash maybe even a bit too much I haven’t dug into that yet. 375 psi shows west and time but still plenty for it to run fine 325 ish is where diesels start getting temperamental. It’s very close right now but out of adjustment. I may leave it where it is, or move it a tooth. Or maybe even send the pump out. Not sure yet but those are what I see as options.

 

[mike11]

Perhaps the pump was rebuilt and bolted to the gear incorrectly? Seems like a stretch but all I can say is the pump is chock full of parts. I found a video online of a guy reassembling one that helped me put mine back together when i replaced the seals. I made the mistake initially of thinking I could do it while it was installed.......but the parts inside had other plans when I did that LOL. Maybe just needs a good cleaning including the lines and injectors?

It may have been apart who knows, and if it was with what I saw in this machine I wouldn’t be suprised at all if something in it isn’t right.