I need your help, I'm new without a clue. I have a 12-1989, LTA10 for 240 ESN# 34594249 Surges at idle, like idle is set to low. I paid a shop in LA to fix a valve cover leak and make the truck shut off with the key. Get it ready for a road trip home. I just bought this Freightliner after sitting for a year. The shop got paid and I still use the manuel fuel shut off. They tried to convince me the surge was a Cummings idle. They took the pt pump off to replace a gasket and the truck is worst than when I droped it off. I'm no diesel mechanic yet but I have to fix it my self and hope you can help me out. What looked like a check valve going to a 1/4 line from the backside of the PT pump was loose and leaking. Part number 3042360. Has a screen in it and dirty. What is it and any suggestions would help. Thanks
Water tender, Might try sending a private message to "thepumpguysc" if he doesn't respond to your question. If you have numbers off the PT pump tag that would help him alot, or even a picture or two might help. As it's been a few years since I touched a PT pump I'll refrain from saying too much to avoid giving any wrong advice. But one thing I seem to recall is Cummins PT system, at least the older ones did not like air in fuel.
I farm my PT pump work out.. but I do know the low idle is set on the end of the pump w/ the pipe plug in it.. not on the side w/ the stop screws. If you do a search for Cummins PT idle screw location.. you'll get a troubleshooting guide from Oregon Diesel, ITS GOOD.. follow it. The reason I farm it out is because of customers.. the PT pumps look the same regardless of HP and application.. The only way to tell them apart is the small metal tag on the pump.. in which 75% of them are missing.. Then your only means of ID is the engine SN, which nobody has or brought w/ them.. Then you get the customers who bring you a PT pump from a salvage yard and DONT TELL YOU that its NOT the pump that's off their engine.. I overhaul it from the tag on the pump, come to find out its a 250hp pump and the fella comes back screamin holy he** cuz he's runnin a 400.. and swapped out my pump for his.. TOO MUCH aggravation.. I just wont deal w/ it.. Good luck w/ yours WT..
Thanks guys I feel like I'm doing good now, my pump has a tag attached with the numbers. 1224x723A under that 01 10 14 DD. I'll check out that Oregon info also thanks. I will get a picture of the brass fitting I thought was a check valve missing a spring, after cleaning I found a screen that was real dirty and leaking no check valve.
Check the return line from injectors to tank, is it clean or clogged?
The lines appear to be clear. Can someone tell me what this part is? It was loose and leaking, I just don't know if all the pieces are there.
When I search it, it comes up a good # but no description other than check valve.. Maybe a drain back check valve?? at over 100.00 you'd think there would be more to it??
That's what I was thinking. I'm in the mountains about 60 miles from Bakersfield, I just might have to take a road trip. I hear check valve and think of spring and a ball not a screen. This little part has a lot to it. The screw has a hole in the center maybe for flow control. I can't find a picture of it to make sure it's all there. This comes out of the pump behind the fuel shut off solenoid. The line ties into the tee. I don't know if you can see the tee. Thanks PG
Pretty sure you have leaking injector seals,,,, especially if it won't shut off with the switch. I fought this same thing on another L10 for a spell before I figured that out.
Really, injector seals. That's worries me. I was told that this engine was rebuilt in 2014. I have a question about shutting down. Is there a constant supply of 12 volts to the shutdown solenoid? I tested mine today with the key on and had 12 volts, key off no voltage. Key on, 12 volts and five minutes later nothing. I guess my questions is with 12 volt at the solenoid and truck idling, when the 12 volt kicks out for whatever reason, wouldn't that cut the fuel and engine die? Sounds like I need another shut down solenoid. What's your thoughts. Thanks Grandpa
Can anyone say for sure that the check valve In The pics is complete and in the right spot? Has an O Ring by the screen. any diagrams of the PT Pump that shows the check valve locations. Thanks I appreciate all the replies, I need all the help I can get.
What do you call the "Manuel fuel shut off"? Is it the screw on the on the front of the shut off solenoid? Because if it is that screw is to manually keep the pump fuel flowing if you loose power to the solenoid.
Chepe, that screw is what I'm having to do to shut this Engine down. To start it I have to open it. So then that tells me that the shut off solenoid is energized until you turn the key off. Right now it only gets 12 volts for a few and then stops as if a relay is opening. So does the screw need to be closed at all times until a loss of power to the solenoid, so you have a way to keep the truck running. Thanks for the help. As you can tell this is all new to me. I'm willing to listen and learn. If that's possible. Thanks again.
The wire going to that solenoid should have power going to it as long as the ignition is on. That sounds like there might be wiring problem, you could run a wire from the ignition switch to the solenoid for it to be controlled by the key.
That's exact what I'm thinking. Just as soon as the rain eases up, I'll be on it. Thanks I'll let you know the outcome.
What happens is all the fuel galleys in the head are full of fuel, you shut the switch off, allowing the shutoff to shut the fuel off to the head. All the fuel in the head will drain around the leaky injector seals allowing the engine to continue to run for an incredibly long time. Chepe is correct on the power to the fuel shut off. If you lose power, the shut off solenoid will close the fuel off. If it continues to run, you have the override screw turned in to hold that shut off open. Put the override screw in the proper positon where the solenoid works, the shut the power off to it and allow the engine to run long enough to cycle all the fuel out of the head. At that point you should hear the engine wither and die, finally. If the injector seals are leaking this will happen.
On more thought, if I remember correctly there is a dished spring washer under the shut off... make sure you haven't lost that puppy.
Hope I'm not making this problem muddier but this screw you are talking about if it is the one on the front side of the shutdown solenoid it should be backed out for normal operation. Turn in to force the valve open to run if there is a problem with the solenoid valve. If engine will not run with 12 volts to the solenoid valve there is a problem with the valve. I believe you have had this coil off the valve. Did you look at the end where the wire is connected? It should be marked 12V, or at least the ones I worked on were marked. Make sure it does not say 24V which most off road equipment would use. Can't speak to the power shutting off after a period of time except that I could see this as being normal if it was controlled by some kind of "safety shut down" system.
Grandpa, Here's a little video that might help the OP to understand this simple valve: https://www.youtube.com/watch?v=SMDKVHikdOM
Good job kshansen,,,, if the plate is in upside down or the spring washer is missing will mess up the fuel shut off... what threw me was when he was turning the screw to shut it off, when in fact the screw only turns it on. If the shut off isn't working and the screw is holding the plate off the seat, the only way to kill the engine would be to put it in gear and physically kill it, or shut the air off.
I need to look for that spring washer, also run new power to the solenoid. This is all very helpful and I appreciate you all for helping me out. I'm going out and see what I can get done and follow up.
Problem Solved To everyone that replied, Thank You. Got my truck put back together this afternoon and She runs like she should. That fuel solenoid even works right, now the key shuts her down. I learned that the manual override knob needs to be turned all the way out and then back it in I full turn. That makes the fuel shut off solenoid work the way it should. I did run a new 12 volt wire that's hot with the ignition. Cleaned every thing up and she starts right up. No more surging, Im HAPPY, HAPPY, HAPPY.
Thanks for reporting your results,,,, were happy for you!!!!