I just bought a 1990 Brush Bandit chipper that has a JD 4.5L turbo diesel on it. The unit says it has 1829 hours on it, if you trust the hour meter. The engine runs fine for a while but seems like it is running out of fuel after it runs at full throttle for a few minutes (2400-2500 is full throttle). It started by dropping to 1980 RPM and never coming back up, but if you take the load off it it (disengage the chipper disk) it will sometimes rev up again. It has gotten worse though, in that the last time it ran at 2400 for about 2 minutes then it dropped down to 1000 RPM for about 30 seconds and then continued to drop until it shut down and would not restart.
Sounds like a classic fuel problem to me. So far I have replaced the fuel/water separator, Napa number 3548, (it does not have any other fuel filter on it) and replaced the feed and return fuel lines. The primer lever on the lift pump (just like a first gen LP) works fine as I have to bleed it after replacing the water separator. When I opened the valve at the bottom of the separator it sucked air instead of dripping fuel. This suggests it can't get enough fuel. I plan to pull the stand pipe out of the tank tomorrow to see if there is a problem there.
It has a Stanadyne injection pump on it. That worries me since it is considered "wear item" on the Fords that used them.
If the stand pipe is not restricted, what's next?

Thanks,
Chris

 

I'm thinking something is floating in the fuel tank closing off the pickup tube or the hose from tank to engine is colapsing. Hook a 5 gallon gas can to the fuel pump and see if that fixes your problem.

 

I would check what diezelsmoke said or maybe check to see if there is a tank vent stopped up. Or try removing fuel cap and see if it still does it as this would be a way to check tank vent Just becareful not to let anything fall into tank.

 

I would also check the fuel line going to the tank. However, there may be a problem with the governor in the Injection pump. I used to work for Deere, and was an engineer in Test & Development, specifically for the 4.5: & 6.8L engines. I agree that the Stanadyne pump is a "wear item". This was the worst part of these engines. We had alto of problems with them. We actually built some 6.8L engines with Bosch P-pumps on them for Deere Graders, and some with Delphi rotary pumps also. B ut this kind of sounmds like some type of restriction in the fuel line. Keep us posted.

 

Is there an in-line fuel strainer? Just a small round canister type of deal. Deere has used them plenty over the years. It is usually before the fuel filter.

Also, if there is a shut-off valve on the tank, is it open all of the way?

 

OK, pulled the pickup, and it is kind of a poor design, as far as I'm concerned. It has not prefilter/screen, just a plastic tube that is cut at an angle. Due to visible trash in the tank, it was pulled and flushed. Dropping the fuel lines into a bucket of diesel, I found that while the engine would barely run, no fuel was coming out of the return line. Further examination of the fuel system revealed some bits of a leaf in the elbow on the LP intake. I believe the LP is good, at least until proven wrong.
I pulled the other lines, from the LP to the separator, and from the separator to the IP and found the rubber gaskets in them were deteriorating, so I'm gonna search for those tomorrow. This is a weird fitting setup, in that it's like a brake line connection, except the fitting goes on the outside of the mating fitting, so nothing actually presses the line into the mating fitting except this piece of rubber, which looks like a piece of hose put on the outside of the metal line. I dunno why JD would do it like that, but it appears factory, since it is on all the hard lines.
Once I get those gaskets/seals on there, I think it will run a whole lot better.

Thanks,
Chris

 

Looks like you found the problem, also that rubber piece will actually wear out the metal tubing if the connection was loose so check the tubbing for excessive wear, I have actually seen the rubber wear a hole through the tubing and ended up sucking air.

 

I am now figuring that the reason JD did that was to counter vibration in the hard lines.
Anyway, got those little golden seals (3.29 each ) and installed them, as well as put the fuel pickup back in with a piece of screen rolled up and stuck in the end (no other way to put a screen on the pickup tube due to the small mounting hole), and put an inline fuel filter just before the pump.
It runs like a Deere now.

One other question, how much play in the turbo shaft is too much, and what is the best way to measure it? When I had the intake off I felt a little play, but don't know if it is out of tolerance. I cannot see anyplace where the wheel has contacted the compressor housing, but I have not been able to get into it real close.

Thanks,
Chris

 

You will get some play in the turbo, the thing to do is put side pressure with your fingers as you are turning it, it should not drag on the housing.

 

agreed. i know its a Deere but Cummins/Holset says as long as there is no turbine to housing contact and the axial play is within spec "X" the turbo is good

 

The side to side is OK as long as the wheels don't touch the housing. It is there for oil clearance.

Noticeable end play is acceptable on some turbos, but not all. As far as I know, none of the turbos that Deere uses has any noticeable end play. As long as there isn't wheel/housing contact, odd noises or oil leakage, usually shows up on the turbine (exhaust) side first, you should be fine.