Hi guys I've searched high and low for an answer to this. I just had very a reputable company called Proformance Diesel in clearfield PA rebuild my Lucas Cav pump on my case 450c dozer. I actually believe this to be a 580 backhoe engine that was changed at one point in time because the timing cover components all take a serpentine belt instead of a v belt like the crawlers had. This was the conclusion the fellow at Groff tractor in New Stanton and I came to. Nonetheless they are both a 4-390 and the engine is the same. Pump installation went flawlessly as did installing a new OEM lift pump and ensuring that all lines were clear with no blockage. Only took about 5 seconds to have fuel at all of the injectors and once they were closed it idled better than it has since I bought it. Fast forward to five minutes of idling and when I started to play with the throttle, it died when I left off. Ever since that first initial shut down, when I start it the RPMs flare up for a second and back down to an idle and die. Hit the starter a second time and it does the same thing but will usually stay running. Performance from the high pressure side of the pump seems to be flawless as the machine runs exactly as it should with no missing or stuttering. WOT also seems better than before rebuild. I double checked for are everywhere and clean the pump up really well only to find a slight weep, apparently from between the rear inlet plate and the pump drive housing. My filters were also leaking so I took them off clean the surfaces and reinstalled what's no leaks now. MY QUESTION IS... I know the slight weep can cause pressure bleed off on the suction side of the pump. However, I don't feel the bleeding off on the suction side could cause the flare-up like that at startup. I will definitely be removing the pump again and taking it to them for them to seal the leak, but was wondering if any of you guys have experienced anything similar before. I'm more concerned about the fact that it idled perfect until I hit the throttle and move the internals of the pump and then it changed. I kind of feel like they should just pull the whole pump apart and redo it again to be sure. Any input would be greatly appreciated guys. Sorry for the long post but I wanted to rule out all the possibilities that you guys were going to tell me to check that were obvious things first
Hopefully ThePumpGuySC will see this and give you some insight...
solved.. hopefully.
They are looking into it. Thanks for the phone call the other day. I was honest about the idle changing and he is consulting with his guys. They want to make it right. Gonna call me back shortly. I'll keep you posted.
One more question for thepumpguysc. These Cav pumps don't require wired throttle to wide open on assembly like a Stanadyne do they? I couldn't find any info but this 1 definitely wasn't
I’m not the pump guy but I’ve gotten those cav pumps back from diesel shop both ways throttle tied and not also lock screw engaged and some not. On the engine that is in your dozer the 450C’s came out with the 4-390.
NO.. the CAV pumps have their drive shafts "contained".. therefore holding the gov. weights intact within its cage.. No need to tie the throttle.. Good luck w. your problem & I hope they come thru..
They found a leak, but it tested perfectly on their stand. Pulled injectors today. Someone had a different style injector in #2 and a 2nd tension clip inside the cap on #4. Spun the centering ball over the ledge and put shards of metal down in...grrr. I wish ppl who didn't know what they're doing wouldn't turn wrenches... hopefully a magnet will work. Piston is up top
Looks like the tip is blown off of #2. That problem u have w it speeding up & shutting down at idle WILL NOT be found on the test stand.. & unless they took the cover off & LOOKED at that piece.. ur gonna have the same problem.. Only time will tell.. let us know.
I'm thinking #3 is alot cleaner than the others & has no carbon on the tip - maybe not atomizing properly. You will need to check if that #1 injector is compatible with the other three ...... me thinks not .......
I rubbed the carbon off of #3 with my finger. Is there any chance you could post a picture of the piece you mean that gets grooved. Sorry, I should've asked for that before. I just want this thing right. They seemed to know what you meant when I mentioned it. Not sure if they double checked though.
If u know what I’m talking about.. then they certainly do.. There’s only 2 ways to find out if they fixed it.. 1.. remove the top cover & look for yourself. 2.. put the pump back on & see if the gov. catch’s it & keeps it from shutting off.. Cuz they ARE NOT going to tell u.. & like I said before, the test stand will not prove it.. Question>> How in the world did it run w the tip blown off the injector.? It must’ve looked like a freight train.!! U have to be real careful buying injectors off the web.. Delphi & Cummins got together & decided it would be a great idea to use the same part # for about 7 different injectors that fit that engine..(about 7 diff. HP & torque ratings from the same motor) U should go by the CPL on the data tag & call Cummins to get the part#.. THEN u can look around.. AND.. replace them in SETS.!! U have no idea what’s in there now.. & if u just change 1.. u don’t know if it’s right or wrong for YOUR engine.. Like I said.. they’re all gonna have the same #.. Only way to tell the diff. is by the nozzle # & u have to take it apart.. DO NOT TRY to take it apart.!!
No worries. Thanks for the quick reply. They seem pretty honest and are very reputable up this way. They have very few issues. Maybe they will buffalo me, but hoping not. I hate to remove the cap because of the warranty. It's easy to install so I'll do that 1st. Taking all 4 injectors to them right now. Let them handle that. For $100 an injector it isn't worth me guessing. The tip isn't blow off. There's just that much carbon you can't see the tip
It honestly barely smoked at all except for initial throttle increase from idle to wot throttle scenario. They found a loose banjo on #2. That could've been the rough idle. It's the wot on startup that scares me. These old non turbo Cummins are so reliable when they're happy that I'd hate to let a fuel issue ruin it. Thanks again. I'll post enough to follow up. If they hose me, I'll ship it to you. I'm at a loss. Fuel, good pump and injectors means nothing left to check. Something is a miss...
Please tell me which # is the part the groove wears in on the image. Thanks
A little better view !
Tinkerer thanks, but I have the PDF on my phone as well. Just need to know where to look for the groove that thepumpguysc was telling me about. I'll look if I have to, but gonna see what happens with all new injectors and everything 100% first. Thanks
Once in a while I will re-post an image that has been presented is hard to see way. The reason is that hundreds of people will look at those images in their quest for information. Thanks for the Thanks Jared !
Tinkerer I understand. I've done the same for about 10 yrs now on here and a CPL other forums. Decided I would benefit more being a member so I could see all the images as well. So here I am, waiting on them to test my injectors and call me back. I figured if I clean the tank and remaining lines, flush filter housing, and have them rebuild the injectors and it still messes up, there is no other possible scenario than it being in their pump rebuild. They are being very cooperative. They even offered to send someone to reinstall it. But it's easy so why wait
You know what. I think if I was in your shoes I might just take them up on that. So they say the pump is OK, (assuming) they say the injectors are OK, they install it and it STILL has the problem then you just look them in the eye and ask "did you inspect such-and-such piece for a groove.?" and watch them squirm............. My opinion (* other opinions are available - YMMV)
Nige, I agree. But injectors definitely look crappy and with bad internals prior to the rebuild, anything is possible. I'm not concerned about my time because it's free right now, but startup season is almost here. If I do all of this, I'm sure they'll send someone down. Also, once thepumpguysc points the piece out, I can make them pull the cover and show me while here. Only takes 10 minutes. Thanks for keeping in touch guys. This is a nice little older dozer. Perfect for what I want. Get this straightened out then on to the remaining undercarriage I haven't replaced yet and cpl ram seals
Beating the injectors to death.. lol As u already have seen the carbon build-up, it might be time to check the pump to engine timing..?? Naturally a machine that old is GOING TO HAVE gear train wear/back lash.. SO setting the timing at "spec" isnt going to apply.. Your pump has the lock timing bolt for the drive shaft, yes.?? Finding TDC on the engine is simple w/ the pin under the pump.. its the actual inj. pump timing that u need to play with.. Set is CORRECTLY initially.. THEN move/rotate the pump every so slightly to the advanced position.. TIGHTEN the pump hold down bolts after EVERY adjustment.!! I CANT STRESS THAT ENOUGH.. THAT will be OPPOSITE the arrow on the name plate.. Your'll probably see a noticable increase in power.. just dont be tempted to go TO FAR advanced.. ..you'll start heating up the engine.. & u dont want that.. Theres probably a "slash mark" on the pump that matchs up w/ the mark on the block.. DONT go anymore than the width of that slash mark.. & that'll keep u outta trouble.. Good luck.
Not enough room to move this pump and advance it. Studs are up against the end of the slot. However, inward rotation being limited would indicate proper gear lash. Something changed after their rebuild. Hands down. I've reinstalled the pump. Waiting for injectors. Could you please point out the piece that could be grooved? I'm going to look if symptoms are the same this time
I also noticed that the throttle arm doesn't freely turn to the idle stop without the linkage connected. Is that normal? Im guessing the spring on the linkage was helping before. Most carburetors return completely on their own. Wasn't sure if these do or not. Just trying to sort it all out so when I put injectors in I'll know where to look. Out of time here
Here is a better picture of governor assembly to point out where the groove would be. Any help is appreciated. Thanks
I already told you where the piece is.. it’s the bushing that’s rides against the mv.. U should be able to spin it w your finger 360* w/o it catching in a wear groove.. Does your pump have lock timing? Did YOU SET the ENGINE to #1 TDC.? Does the drive shaft have a key.? Did the pump slide right in w the drsh locked.? Being up against the studs doesn’t sound right to me..
#8 is pointing to the spring.. then there’s the bushing, then the mv.
Yes pump has a lock. Pin is locked on engine. Yes it has a key and slides into the gear perfectly. So you're reffing to the bushing between the spring and where metering valve clips on? That would make sense. Thanks so much.Everything sure seems legit to still have problems. Up against the studs seemed strange to me also, but out of time is out of time. It runs, just starts with throttle flaring up and dies after. If I catch it with the throttle it stays. I'll laugh if I pull that cover and find something off in there. They could've done that easily 2nd time around
That’s why I’m “THE” pump guy.. I do it right the 1st time.. Hope it goes well..
See - You shoulda had them put it in........then "their man" would've seen it for himself.
See, thats the thing about fuel shops.. They have a NO, its not our fault policy.. & a warranty that states they are not responsible for ANY charges incurred if it is.. No labor, no lost wages, NOTHING.. BUT, out of the kindness of their hearts, they wont bill u if it IS their fault.. lol Thats why I told ya, NOT say anything about any leaks on your end.. they WOULD HAVE blamed the entire problem ON U.. & charged u 2-300.00 for a calibration check, to which they werent gonna find your shut-off problem ANYWAY. The test stand wont show that problem.. Let me see if I can explain it so folks understand.. On the engine, the pump drives the engine.. On a test stand, the machine drives the pump.. & your gov. problem wont react to the test stand.. I hope it clears it up somewhat..
Appreciate all the info thepumpguysc. I have 4 new injectors now, 2 new filters, all new banjo washers for the inlet lines. And yes, that makes sense that the stand won't show it and they AGREED. Also agreed that something could be off in there. IF it isn't right this time, they are sending someone down free of charge to pull the cap and address the problem. Going to video everything today. Thanks again guys. This is my first diesel experience and I already know more than half my friends. Lol. Perhaps that's why I rebuild some of their kids dirt bikes. Hahaha
I was just reading back through this thread and this made me laugh ........ They are obviously nowhere near as reputable (or competent) as either they think they or or as they had you believe. If they were'nt aware of an potential issue as basic as that on one of the most common FIPs out there, *** do they work on in their day job..? Amazing that it took so long for the fault that pumpguy pointed out days ago to get through to them. You could've had this sorted at much less expense and trouble a week ago if you'd listened to his advice and acted on it instead of taking the "reputable company" at their word. I will point out that the foregoing is my opinion. Other opinions may well be available.