Hello people, I have a Caterpillar 320 DL with a long time issue. Firstly it has an issue that the machine turns off. We changed injectors, check the power shift valve and everything looks fine. Then the machine doesn´t even start. We found out that the solenoid on the top of the high pressure fuel pump was broken. We changed that, but the fuel is not coming out of the pump. We checked and the fuel is going without issues through all the lines and goes into the pump, but then it doesn´t come out to the injectors. We also changed RPM sensor of the engine, and of the fuel pump. I attached an image, the fuel is entering the pump in 1, but not coming out in 2. The solenoid 3 we changed already, but nothing changes. Does anyone know how we can check if there is signal reaching to the solenoid, or which test can we do to solve this issue? Thanks
So I think that pump needs to be timed. So if you took it off and rotated it, it could be off. Also, I think that the rear section is the mechanical lift pump. You can try to hook up cat et and you’ll see under the starting tab it has primary and secondary speed sensors. And it will show if they are reading correctly. If it shows injection disabled or timing pattern erratic you have a problem. Your pump also might have been the issue the whole time. If you don’t have access to cat ET, you can try to unplug the speed sensor on the pump, and if it tries to start, you know there is a timing issue.
Post a Serial Number. With a model as common as a 320D it might help a little to know exactly what you are dealing with.
The serial Number is A8F00985
It does, and the bad news is that apparently there are no factory timing marks. For pump removal the procedure states "Place a mark on pump drive gear (2) and idler gear (3) for assembly purposes." So if either the pump or the engine was rotated after the removal of the pump the pump timing will likely be off. The engine can be locked at TDC on No 1 cylinder using a timing pin. Before removal of something such as this HP pump I would always suggest to do that procedure first. It is. Another unfortunate fact is that the 292-3751 fuel transfer (lift) pump contains no serviceable parts.
The pump was for sure rotated because it was sent to an especialist in fuel pumps to check if everything was ok. Is there anything that I can do with the pump removed from the engine to check the alignments or if it is working properly? Then I will put again the pump and check with the cat et and unpluging the speed sensor.
So there is a timing tool for the pump. You can time the engine to no1 TDC, then buy that timing tool for the pump.
What did the specialist say? Is the pump good? The reman pump will come locked and timed. Might want to quote one.
I will check the tool. The specialist repaired the pump and give it back. In theory now it is working.
Ok. So once you get the tool and time the pump, there is a bolt on the side with an oval washer. Unscrew it enough to rotate the washer so that the bolt sinks deeper and locks the pump. Once you install the pump and the gear, then you loosen the bolt and flip the washer back so it acts like a spacer.
And once you have the pump locked in the correct position the engine has to also be set at TDC on No 1 cylinder and locked into position.
Is there any tutorial about how to time the pump? How should I know if it is timed or not?
The tool goes on the shaft and rotates it until the pin slides into place. Here’s a YouTube link.
Perfect, thank you! Do you know by chance how can I check if the solenoid (3 in the image of the initial post) is working properly? What voltage or signal should came from ECM to the pins?
Way easier to hook up cat et while cranking to check if the solenoid is functioning. You will get active codes if there was a wiring issue. It’s not a simple on or off solenoid. It pulsates to control the amount of flow to pump produces. Time the pump, time the engine, install, hook up cat et, let us know. Is it a 2 pin solenoid? Looks like pin 1 is signal and pin 2 is ground.
Perfect, I will follow those steps and then let you know. Thank you for the help.
You may be able to bypass purchasing the timing tool. Unscrew the bolt that Island_catguy mentioned in post #10. Look down the hole with a light and slowly rotate the shaft. If you are lucky, you will see a witness mark where the bolt previously locked the pump in time. Line it up again and you should be good to go.
Nice trick, I will try to do that also. I am already asking my distributor for the tool just in case.
So, update. We checked everything with Cat ET. Speed sensors are ok. The issue is the solenoid of the fuel pump. The target is 38000kPa and the engine is working at aprox 47000 kPa. We already have changed the solenoid. With the old one (it is broken on the thread inside), the machine is starting but with too much noise and too much fuel pressure. With the new one, the machine is not even starting. The springs inside the solenoid are not the same, and the new one is a bit loose. How can I check the regulation of that part?
Update #2, today we tried again with both solenoids, they are not working. We even take out all the inside parts of the solenoid valves and fuel is not coming out the fuel pump.
Update #3, we dissasembly the top part of the pump. In the middle of that, there is a small ball that works in a hole that connects both of the pistons. We believe that that ball is stuck and not moving. When we blow air from the piston the air is coming out from the other piston without restriction. So we believe that there is no pressure being generated in the pump.
So you are going to get a new or reman pump now?
We think that the issue is on the head of the pump. We think that the ball is not working properly so the pump is not working properly. Does anyone knows if the top part of the fuel pump comes as an CAT part? I that the pump is the 236-4635, but I am not finding the top part Nº.
I think you mean 326-4635. Other than the parts indicated by Ref # 1 to 15 in the illustration below there are no other serviceable parts on that pump. Your only choices are a new pump or a 10R7662 Reman pump as indicated by @Island_catguy above.
Yes, that one. Okey, I will need then a new or reman one. Thank you!
When you receive the replacement pump it will be locked into position ready to install on an engine that has been correctly timed as per the service manual procedure. So before you install the pump and unlock it you will need to time the engine first. Maybe @Cmark can suggest something regarding how you can possibly time the engine without the need to remove the front timing cover.
Thank you @Nige and @heymccall