1374-4 engine fuel pump pressurizing assembly #1 voltage below normal In short we have replaced the fuel pump and fuel pressure sensor to try to fix this issue. We tested the plug to the pump and it shows 1 ohm and reads 12v. I don’t think it’s the harness but what else could it be?
Sorry can't find anything on the engine S/No. How about the machine Serial Number.?
Was just about to ask the same thing Nige... Injectors, a poor electrical connection somewhere else, corrupt software/ECM. They're the first things that comes to mind. Can you please post the machine serial number. The picture you posted is the engine serial number plate, which is good, but it doesn't give us all the information. Can you also please give us some background of the problem. Is this a crank, no start? Is it just running rough? Is this code randomly appearing and everything else is fine? Just need a little more info.
Also which pump did you replace, the transfer pump or HPFP (High Pressure Fuel Pump)? You replaced the fuel pressure sensor in the rail also?
I have that information down on a paper I printed off but it’s in my toolbox at work. I’ll have to get back to you on that on Monday. Thanks for responding
Is this a machine you have posted about previously.?
We replaced the fuel filter with the pump on top. I believe that’s what it’s called though. It’s at the end of the fuel rail. It’s a 1 1/16 socket style I believe.
No I have posted on other machines as well. Some of them we still couldn’t figure out so they put it aside and we started working on other things.
The machine will start and run fine for maybe 30 seconds before it shuts itself down again. You have full functions inside the cab. It revs up just fine everything but after so long it just dies.
Kc601637 is the last 8 of the vin
The water separator assembly needs removed, fully disassembled including the inlet elbow, and the entire inlet path cleaned. The pump unscrew from that filter head. There is no screen between it and the priming pump, and all the tank debris collects in the elbow and head, restricting the flow of fuel. Be sure to clearly mark the fuel lines where they go before removal.
I changed that whole assembly already though. Could something else be possibly blocking it?
What if I tried to shoot air through the fuel lines to unclog anything that may be blocking it
It might be an off the wall suggestion but have you tried opening the tank drain to see what sort of crud is lying in the bottom of the tank..?
I haven’t no I’m not sure you can drain the fuel tank but I will double check. Hope I don’t have to pull everything.
Oh yes you can. It's part of the PM scheme in the O&M Manual, the bit that no-one ever does in the manual no-one ever reads........... See attachment.
Ok I will try that. Is that 9 ft lbs that you torque the drain plug to?
It appears as though it all depends on what type of tank & drain plug arrangement is installed on a particular machine.
I’m about to pull it back in and check. Hopefully it’s just crud in the tank. I’m going to blow some air through when we drain it to see if anything comes out
So I blew air through the hoses for the fuel lines and drained the fuel. A little debry came out but not too much.
We are thinking we might just replace the harness and see what that does. It runs great, no knocks, noises, or engine stalling and then 30 seconds late it dies with that code still showing
Back to your original question. The Code is 1347-4, not 1374-4 as you posted. That explains who nobody could find it..... See attached. You may need ET.
Sorry that most of been a typo
I just thought about it again a few minutes ago and on the basis of the machine Serial Number went into the master listing of Codes and started looking through it. It popped right up. That's why it's so important to always include a machine Serial Number.
Where is the scv located at exactly?
This is what it’s saying
#5 is SCV (Suction Control Valve)
Thank you. I ordered it and it should be here tomorrow. Fingers crossed
Did it test bad.?
The wires tested fine but I just replaced my scv and the code went away. Thank you to everyone who helped me to diagnose this
Would love to know the resistance readings on the old SCV. Should be 2.1 ohms as per the troubleshooting procedure. I'm expecting yours wasnt?
I didn’t test it we tested the wiring and had a resistance of one which we assumed was correct. I’m still new to this so I’m just learning
One of these days you’ll replace a part then come back here with the “I replaced X and that didn’t fix it. What do I do now.” Of course the answer will be that had you performed the troubleshooting procedure correctly and by the book it would have shown you what was wrong. Some times it’s not the component but the wiring that’s the root cause.
I completely agree as well. It’s like the inclinometer sensor I just replaced and the code still pops up. More than likely a harness issue
I still have the old one I will test it and see the results and post in a minute
So after testing the scv it only has 1.8 ohms which I’m assuming isn’t enough to function correctly
Thanks for that. I've tested these before and found that the required 2.1 ohms needs to be dead spot on. That confirms my theory. Not that it matters anymore, but I wouldn't be surprised if some (if not all) of those 1.8 ohms is just the resistance in your DMM leads and the SCV itself is shorted internally. Either way glad you got it running.
It’s amazing how only .3 ohms would cause so much issues in a machine. It definitely through us through a loop until we changed that. I’m glad I know it now though. It helps when you can get the schematics of the overall diagnostics of the machine your working on.
Try testing the resistance of your multimeter leads as @Chrisso suggested. Just touch the two probes together and see what it measures. The. When you measure the resistance across the SCV deduct whatever from 1.8 ohms and you’ll have the true resistance measurement of the SCV coil.
Ok that makes sense. I will do that and post results