I recently bought a case 580l backhoe knowing it needed a bunch of work. I'm a pretty good at figuring out mechanical stuff but the injection pump has me stumped. It had been ran on some really nasty fuel which was clogging the filters. Got that all cleaned out and now when I start it it starts fine but runs up to 3/4 throttle with no load regardless of the throttle lever being at idle. I removed the pump and disassembled it completely to get everything clean and moving freely careful to not change any settings. Reinstalled it and the rpms were just a little high at first but quickly crept back up and stayed there about 3/4. When you put a load on it the rpms drop back down so maybe a governor issue but it all looked good when I had it apart. Any ideas aside from getting it rebuilt would be greatly appreciated. I'll get it rebuilt if necessary but I'm so deep into this thing that an easy fix would be nice for once. Thanks in advance!
Engine is a NA cummins 4bt. I don't have any serial numbers at the moment but will post them when I can. Still new to the forum and it's my first time posting.
An easy fix won’t be the right fix. IP’s need to be calibrated which you can’t do. I would send it to our resident rebuilder (TPG) versus risk burning the engine up.
I understand it needs to be calibrated on a stand to be right and if that's the case I will send it off and have that done. Right now I'm mainly wanting to rule out anything outside the pump that could cause this issue. Such as it sucking air or a clogged return line. I just want to use it around my place so it's not a pressing issue to get it going at the moment. I just want to rule out all other factors before I drop the change on a rebuild.
And it's a cummins 4b non turbo not 4bt didn't mean to put the t earlier
The governor for the engine control is built in the pump. The only thing I can think of that would cause something like this is that the governor is not properly set and/or adjusted. This is more than likely due to it being torn apart and reassembled with something not correctly fit. Some governor types can fail or lock up and cause a runaway, but I don't believe that is the case here. The only other way to override the governor would be for a combustible liquid or gas that enters the air intake system.
Well I was the first one in the pump because it still had the factory tamper wires on it. The problem existed before I took it apart and cleaned it. If anything it's slightly better afterwards. I'm no expert by no means but I've had success cleaning them in the past so I gave it a try here. At the end of the day it's mine and if I make a mistake it's on me. It's hard to learn a new skill if you always pass it on to someone else. I was just hoping someone on here might of had the same issue or to gain a little extra knowledge on what it could possibly be.
It's not running away. The fuel shutoff still works and it's not over revving. It's just acting like the governor isn't applying to maintain idle rpms unless it's under load by the hydraulic pump or transmission.
@thepumpguysc < If you want it rebuilt, send it to him. I've heard he accepts bad checks LOL Hopefully he will chime in here soon.
Can a stuck regulating valve cause a high idle situation because of to much transfer pressure?
Unlikely..........but post some pics of your IP pump and the tag on it.
Hope they are good enough quality I've never posted any here
Have you tried adjusting the throttle lever "backstop" that controls the arms idle position? Did you have a manual that showed exactly what you had on the inlet end between the inlet pipe and the transfer pump vanes? That's a part that has something to do with speed, and is easy to mess up if somebody removed the fuel supply pipe trying to fix a different no start issue.
That is a good point on the inlet. I've been wondering the same thing since it had issues with dirty fuel. If the previous owner might have took that filter out and got it mixed up somehow. I don't have a manual on this specific pump but everything seems to be in the right order. Compared to other pumps that are the same Era and style. The little piston inside the inlet was a little seized in its bore when I cleaned it. That's what made me wonder about the transfer pressure being an issue. As far as the throttle lever goes I haven't made any adjustments. Since the issue started out of nowhere I've been reluctant to make adjustments but I'm going to turn down the idle screw slightly and see if the rpms come down. Is the there somewhere to look up the breakdown on a specific pump to see if maybe they had done something to the pressure regulator. Like spring locations and so on
probably metering valve worn out is letting more fuel bypass it therefore higher engine speed very common on those
Thanks for the reply. I had wondered that myself it didn't show any signs of wear but at those tolerances I'm sure it doesn't take much. Any idea of where I could source a new one for that specific pump.
There are many technical documents for those pumps online. These workshop manuals and user guides give a lot of info about all aspects of those pumps. I’d suggest reading thru these in addition to your other activities: https://www.fujiyachts.net/manuals/CAV%20DPA%20Pump%20Rebuild%20Manual.pdf On the site below, scroll to the bottom to see the documents: CAV DPA manuals - Diesel Injection Pumps CAV DPA applications: CAV DPA 3230F030 Massey Ferguson Perkins A 3.152 CAV DPA 3230F180 Massey Ferguson Perkins A 3.152 CAV DPA 3230F350 Lindner BF 350/450 Massey Ferguson Perkins 3.152 Perkins 3.152 CAV DPA 3230F420 Perkins 3.152 CAV DPA 3230F450 Massey Ferguson Perkins 3.152 CAV DPA... injectionpumps.co.uk
There's some good information there. My problem now is finding the right parts for my pump. I guess I'll give my local pump shop a call and see if they can source them. I'm about to the point of just having them go through it and be done (hopefully lol). They have always done a good job in the past but I just wanted to figure it out on my own. These pumps are are fairly simple aside from calibrating.
send it to the pump guy on here he knows his stuff and is reasonable
Have u disconnected the linkage and ran it by hand.?? It might be something as simple as an idle screw adjustment.. Please don’t go monkeying around inside that pump.. Nobody appreciates it and it ends up costing you more.. Have u cycled the manual shut off about 5-6x.?? It’s the other lever on the top cover..
I'll be waiting on his next thread "I lost my engine after my IP rebuild."
I have had the linkage off and worked the levers by hand with it running. Didn't seem to change anything. It revs to probably around 1800rpms while the lever is against the idle screw and if you move the lever off the idle screw it will Rev past that. The manual shutdown lever still functions as it should because I had to use it to slow the engine down enough to get it on a trailer and get it home. All I did inside the pump is clean the dirty fuel out and make sure nothing was obviously wrong. I did change the seals. I did my research before hand and knew not to take the 2 bolts holding the fuel setting plate loose. Could an idle screw adjustment bring it down from that high of an rpm? It almost seems like fuel is getting past the metering valve. The valve had the vertical slot in it and on one side of the slot had a slight chamfer which looked to be machined. None of the valves I've looked at seem to have that though.
Vetech63 Your the reason people are afraid to come here for help. There's no need to be disrespectful towards someone trying to fix their own stuff. You've been no help at all and only offered negative criticism.
This is what concerns me the most. Unless you were involved with the repair before your repair than you have no idea what is even right on your IP. Your problem is something you inherited and what you are trying to do isn't correcting that. I'd bet someone before you tampered with it in some fashion and doesn't have something right.........and you, with no experience are just assuming what you're seeing is correct. Send it to TPG
I'm not trying to be a prick here. I'm trying to give you the best advise possible based on experience. IP are something you just don't fool with............it's the life and operation of your engine and it HAS to be right. If I am coming across as negative, then I apologize for that. It's just frustrating trying to get novices to understand some things need to be done by the experts.
I admire your ambition, SJ. But from what I have read so far, you are in over your head on that pump. I hope you are prepared to shut off the fuel or air to that motor if the rpms go way beyond the governor setting.
Yeah, what they said..
I’m all outta snarky remarks, lucky u.. On the name plate is the main governor spring position.. Most of them are spr code “1”.. Your code is: fuel quantity/at x rpm/spring code/max governor speed. With this information u should be able to get it right.. Good luck.
Lol.. how true, how true.. I’ve been dismantling a JD310SE ALL FLIPIN DAY “trying” to get the injectors out.. I just don’t have it in me tonight.. but bet ur azz id be all over it, if’n I felt better.. I think that info I posted will set him on the right path..
well thanks everyone for what help you have offered. Just hoping for a maybe easy (cheap) fix but I kinda knew that wasn't the answer here nothing else on this backhoe has been. The thing was a basket case when I got and I've slowly been going through all the hydraulics and transmission when I get free time. Once I get everything sealed back up I'm gonna pull the pump and have it went through.