I'm no mechanic, and need to hear from those familiar with Deutz engines. I have a 1998 Ditch Witch 3700 backhoe/trencher, and it lacks power.... to say the least. It hasn't been able to climb the ramps on my equipment trailer, for some time. Several years ago, it would nearly jump onto the trailer. Now, it will barely move forward on the slightest incline of soil. Lack of drive power has become a real issue. What can you offer please, to lead me in the right direction of finding a solution, to regain the power this engine should be putting out? I have recently changed the fuel pump. Thanks for any and all suggestions.
Is the engine slowing down? is it smoking when it's slowing down? Have you changed the fuel filter?
Delmar, Thanks for your response. By slowing down, I'm not sure I know what you're asking. It still will run at high RPM's, but doesn't transfer the power to the wheels. At low RPM's, it does smoke some. No, I have not changed the filter, but have it on my to do list.
Sounds like the hydrostat drive is dying to me. Not an engine problem.
Is it more powerful when it's cold, and get weaker the hotter it gets? Have you changed the drivetrain oil? filter? If it's not slowing the engine down, it's not an engine problem.
This is a good one, here. Thanks Delmer, and RZucker. It was from your comments I sought further into my issue, using different keywords in the forum. I found a person with the same machine and same issue, posted in 2018. I believe it was KenM. He discovered the tow/haul foot button at the backhoe operator's station was faulty. I checked with the Ditch Witch dealer to see if that could cause the issue. He stated to take one wire off of the switch and try to drive it. Bingo, it climbed right up the ramp, by barely any use of the throttle. Forums work when good persons like you contribute your knowledge and experience. Thanks again, so very much.
You still gotta change your fuel filter
Ha, I definitely will.
Been using the machine for several years now, without major issues. Recently, I put a new fuel pump on, out of need. (wouldn’t start) Got it going then had problems again getting it to start. Installed new fuel injection pumps, and injectors. Runs fine until it gets hot, then dies. Also, just noticed it is dripping out of two of the fuel injection pumps, as pictured. What next? Thank you for your help.
After installing the pumps, should have sealed the lock wire hole. It usually looks like a short nail with a silicone seal around it. On the front of the timing cover is a solenoid tucked up against the alternator. Odds are, it's getting tired or the contacts to the square DIN connection are getting loose. Good luck
Thanks FWF. I’ll correct that with the lock wire holes. The solenoid you speak of, is it the fuel shutoff? Any feedback on the overheating issue? I removed the oil cooler and degreased the fins.
There is a thermostat in the oil passage leading to the cooler. Might do a search. A member had an overheat concern recently. Described exactly how he confirmed the fault and corrected. Before we go down troubleshooting the coolers. Did the overheating start before or after pump replacement?
Thank you for your continued help. The getting hot and dying started after the installation of the new fuel injection pumps and the injectors.
Verify that the pumps are "in time" Some pumps have slotted holes, so that the pumps can be rotated to adjust when they deliver fuel. Sometimes one or two can be a little "hotter" than the others. You can tell by the sound. Some holes will hit harder then others, the trick is to get them all singing the same song. Depending on application, some pumps are shimmed for timing. Were there any goofy looking gaskets between the pump and deck?
Yes, there are a few shim gaskets under the fuel injector pumps. When running, it actually sounds very good. I ran it today, digging a good-sized hole with the backhoe. It never did get too hot, nor leak from the holes on top of the fuel injector pumps. I’ll have to run it as a trencher, and get it hot to see what happens.
As long as you don't hear a fuel knock, I guess you're good to go
Thank you again for all of your help. I’ll report back when I run it hard, trenching.
As a side note, as I used the backhoe yesterday for several hours, it never did die from overheating. Out of curiosity, I put the IR gun on it to see what temperature it was running at. The block and the oil cooler were reading in the 275-280 degree range. The muffler was at 320 degrees. These temperatures are with the engine cover and the hood removed.
That’s pretty hot.
You never wanna run without that pump / side cover. That is your entire cooling package. Some air through the cooler, some across the head. I wanna say you shouldn't see above 260°F ever. The oil can only do so much
Thank you for that information. I shall put the covers back on. It was my thinking that they would just be trapping heat.
No, that guides the air from the alternator fan across the head and cooler. Now if you wanna blow all that clean so you have air flow, no one would complain about that.
I blew that all out, yesterday. I understand what you’re saying on air flow, and it never crossed my mind.
I put the covers and hood back in place, and so far so good….. Thank you.