Hey guys, I just got done helping my mechanic put all the external stuff back on my 953b (fans, belts, air filter box, ect....) yesterday. It cranked an ran fine yesterday but I didn't drive it around, I just ran the bucket and arms a little. Anyways it has a freshly rebuilt motor, built by my mechanic, in it. We had to have cat come out last week because the motor wouldn't stay running long and it was missing and blowing a lot of smoke. Cat found were one push rod had slipped out of place (explained the missing) and said that it was running rather ruff because the check valve was bad on the fuel return. We replaced the check valve and fuel priming pump and it cleared everything up but it still was blowing grey smoke pretty good but my mechanic said that was to be expected until I broke the motor in good and seated the rings good. Cat checked the fuel rail pressure and said it was great and holding fine ant low and high rpms. Well I whent to put antifreeze in the loader today and get it ready to be moved. Cranked it and let it warm up, everything running great set aside from some the grey white smoke. Throttled it up to 3/4 throttle and the smoke died away pretty much. After letting it run for about 10-15 minutes I decided to drive it around and play on it some. Once I started driving it the motor started acting up when it got put under a load from driving forward or reverse and running the hydraulics. It operated fine for a little bit but then started choking out when driving it around. The motor would bog down and it would start blowing a good bit of black smoke. Once I put all the hydraulics back in neutral, the rpms would build back up but the motor was running ruff. I let it continue to run on low idle and it cleared up and started running smooth again. Tried driving it again and the same thing happens. Let it sit at low idle and smoothed back up. I took the air breather off of the back side of the turbo and checked to make sure it spun freely and didn't have any play in it. Took the air filter out and ran it to make sure it was getting adequate air. It seems as if I have something going wrong in the fuel system? What is your opinions on why the motor would run ruff when the hydraulics are engaged and then continue to run ruff after the hydraulics were disingauged? Many thanks for all of yalls advice!
were the injectors removed or replaced? If so, one or more may not be seated correctly. Were they set up according to specs? To check if they are seated, put a sight glass on the return fuel line and watch for bubbles. alot under load usually an injector not seated. If it runs really rough, its normally #6 barley noticeable its normally #1 It could be any inbetween.
Hey lee-online, Many thanks for your opinion! The injections were rebuilt and origanly installed by cat with new cups and a whole new injector controle rail. Then when cat came out and fixed the push rod that slipped, they had to re adjust all of the valves and recalibrate all of the injectors. That is still a possibility though! I might have to check the fuel return with a sight glass!
Running through a sight glass is how we check all 3116's after we do injectors. I have cut the cups so they looked nice and clean, seated the injector and sync'ed it only to have a bad seal. Under load/boost it allows air into the fuel and then it runs rough. The fuel enters at the back of the head, #6 so whatever one is allowing air in effects those down stream from it. At idle it may run fine. Some bubbles are normal, its a lot of them that rush through under load that indicate a problem. If it runs really rough then it may be like foam. Connect a sight glass at the check valve, point it uphill and connect the line to the other end and run it. There could be many other things, I am just guessing based on the work that has just been done.
Thanks a lot lee-online!!! I will check that tomorrow afternoon if I can find a sight glass available somewhere. Wear do you normaly find a sight glass ready available? Also if I am able to find one then I just hook it to the check valve and other end of fuel return pipe and look for a lot of bubbles comming through at low idle and high idle? Does it need to have the load put on it? So many thanks for your advise!
How much a badly seated injector affects engine performance depends on which cyl it is in. #1 has little affect but #6 will foam the fuel supply all the way down from 5 to 1 starving them all. Once that is corrected you may have a linkage or HPCU adjustment problem causing engine overload. Do linkages first. Later Bob
Hey bob, What do you mean by linkage or hpcu adjustment? Many thanks!!!!
When the cab was flipped/ engine removed you had to unpin the linkages. Is the underspeed override valve adjusted correct. HPCU = Hydraulic Power Control Unit = hystat
All of the linkage to the HPCU, Speed and direction, Rh & Lh steering, Speed and brake and Underspeed override linkage needs to be adjusted from time to time. The Underspeed override is connected to the throttle and allows the machine to move a low engine RPM. This is for moving not working, mach will stall under any load if the link is not connected or out of adjustment. Later Bob
All of the controls seemed to work great! I'm not sure about the under speed over ride? I do know that the machine did move at low rpm fine. It seemed to have more of a problem at higher rpms. However the motor did bog some when I moved it at low rpms, but I kinda expected it to at low rpms. Should I try moving it tomorrow with the controle lock for the v pattern forward and revers down?
To adjust the underspeed override, With the engine off, pull throttle all the way back untill it locks. Then disconnect the short link between the end of the throttle and the back of the HPCU. Lift up on the link untill you feel the resitance on the lever of the valve. Adjust the link untill the linkage pin just fits. The lever can be lifted more but stop when you feel resistance and adjust to that. Later Bob
Is the engine timed correctly?
If it ran somewhat ok before the rebuild then i would guess it is related to the rebuild or removal of the engine. Why was the engine rebuilt?
Don, the timing is done with the "Top Set" like a Detroit. Later Bob
Yeh the timming has been checked twice! The motor dropped a valve on the second cylinder. It sait broke down for a little over a year. The turbo did have a little water in it when I looked at it before I bought it. I talked to a humongous grading companies head mechanic today and he said that he thought it sounded like the turbo was bad. What is all of your opinions on the possibility of the turbo? The mechanic said that even if it felt tight and spun freely, it could still be bad? I also,talked with a turbo repair shop and they said that if it dropped a valve then it could have easily most up the blades in the turbo and still fill tight and spin free? From the symptoms I have described, do you think the turbo is another possibility? It rained all day hear so I did not get a chance to work on it any. Many thanks for all of your support and advice guys!!! Thanks, John
It could be very likely that when the engine ate the valve, the pieces being spat out of the exhaust could take out the turbine blades on that side of the turbo. Depending on how bad it is, there may not be enough turbine blades left to drive the turbo with the exhaust gasses... I know nothing about the engine in that machine however so I can't help with any of the other symptoms...
Nah IMO the turbo is fine from what you have said, Has anyone checked cam timing? Btw it sounds like you need to fire your lube man and hire a real mechanic. Pj
I think that when it sat for the year, you have water in the system, i would clear all lines and filter/ tank. good luck, sam
Thanks guys! I took the turbo off today and took it to get reconditioned. I got another mechanic scheduled to come out and look at it on Saturday. That is if the turbo doesn't solve any problems. Y'all have gave me a lot of great advice! Keep it comming.
JCA, any time you have an engine failure that involves broken parts, do the turbo. They catch any debris from it and it eats the turbine fins. Been there done that. Later Bob
Hey Bob, I took the turbo off yesterday and took it to my local turbo repair shop. Of course they said that it was comepletly gone..... Well there repairing it for me so hopefully it solves te problem! They said the exhaust fins wear shot and the shaft was worn out. I sure hope it fixes the problems! I need to make some money with this machine to pay for all of the investments! Thanks guys! John
Well I finally got the the turbo back. I put it on last night. Well I just drove the loader around (down small incline hill 10% grade) and pushed some small 12" pine stumps out with it. Did fine. I decided to drive it back up to the truck to put the plate back under the motor for protection. Well as soon as I started going up hill she started running ruff and doing the same thing. The turbo helped some I think but it is still giving me the same exact problem when put under the load of a incline in grade. This is getting very frustrating. Thank y'all so much for your help this far! I'm getting ready to adjust the slack out of the hpcu! Let me know if there is anything else I should check! Thanks!
Is this the lever on hpcu that is connected to the throttle, that was talked about on adjusting the underspeed override? http://i1097.photobucket.com/albums...37-BB09-625E6CB49105-413-00000043FDC0CD61.jpg
Yes. Pull the throttle back to full with engine off. Take pin out of rod end, lift lever up untill you feel resistance(start of spring compression) and adjust length of rod untill pin just slides in freely, then lock up adj nut. Try this out, if rod needed to be shortened you likely have it fixed, if not the venturi bypass needs adjusting, need tach on engine and brakes locked for that. Later Bob
Hey bob, I took it loose and tried getting it to the tension part and it never got to a point that it had restriction. It's just loose and doesn't get to a tight spot. I'm talking about the valve that comes out of the hpcu. What does that mean?
Can you not lift the lever up and it stop against something inside? Later Bob
I believe it would stop at the 12 o'clock position but I will have to check it tomorrow to be sure. If it is stopping at the 12 do I need to make the linkage short enough to bring it to that position? Thank you a lot for all of you great advice and help on my problems!
It should stop before that. It is a rotary valve and has a long roll pin drivin into it's shaft. The roll pin hits a screw with a plunger in it. The plunger will allow some over travel. I suspect someone forced it too far and brokw or bent the roll pin. For now check how much shorter you can make the link when you reach the end of the threads. Later Bob
Well I pumped all the old fuel out of the loader and put new in and added some cetane booster. Ran it for a little while (15 minutes) and tried going up hill (10% grade) and it did the same old dieing out bogging down thing. Turned it around and she backed up the hill completely fine full speed. After that I decided that I was just gonna run her for a while and continue stumping and clearing this 1/4 acre lot for my buddy. I ended up running it for about 3 or 4 hours stumping and clearing and I noticed that after I ran it for a good hour down hill she started doing fine up hill! After I finished pushing everything up into a burn pile I put it at full throttle and full speed up the hill I kept testing it on. Guess what? She did fine and didn't bog down on me! I'm not sure if I have comepletly solved the problem yet but she sure did run good after about 1 hour! I guess I'll just have to run her some more and see if the problems re acure. Many thanks for all of your help guys! I will post some pics of it when I get a chance. Thanks John
Glad the ole girl straightened out for ya, did u ever find any fuel algae like we talked about?
I'm not sure if there was fuel algae or not. The last 2 gallons sure was pretty yellow looking. The tank kinda looked dirty as well but when I scraped the tank nothing came out.
Most of the times it plugs filters, suction screens and for some reason it tends to grow inside rubber lines more so than steel lines,......i still haven't figured that one out.