MX5200 fuel pump pressure

[RHR]

Does anyone know the pressure between the mechanical pump and the injector pump.
And maybe an idea on the volume? It seems like there is little discussion on the mechanical pump.

 

[North Idaho Wolfman]

Very low pressure, almost non measurable.
and low volume.
Neither of which is an issue as the engine uses very little fuel per min.

 

[whitetiger]

Pressure is approx 1 to 3 PSI and the fuel should flow in even pulses.

 

[RHR]

Very low pressure, almost non measurable.
and low volume.
Neither of which is an issue as the engine uses very little fuel per min.

My problem is that I keep getting a red light and and low rail pressure code. Turn off tractor and back on and it runs fine until it gets loaded with the mower in tall grass. It will run fine if I don’t load it. New filters, clean system and new fuel. It starts immediately. I guess i’ll try a new injection pump next.

 

[RHR]

FYI
I put a gauge on it and it is + or / 70 psi at idle.
I’m still working on the p0093 code. I have found a small leak at the rail pressure sensor. It drips and when I raise the RPM it drips more .
I’m hoping it’s just the o ring.

 

[whitetiger]

I should have read your heading closer. In your first post you stated between the mechanical pump and injection pump. I now realize you have a common rail fuel system.
FYI, you do not have an injection pump, you have a high-pressure fuel pump.
It does not operate anything like an injection pump, and testing is completely different also.

The pressure from your fuel pump should be a minimum of 59PSI, so your good there.




Checklist

1. Confirm the code as P0093 / SPN 1239 FMI 1 on the MX5200, and check whether P0087, P0088, or P0089 are also present before chasing P0093. [1][2]
2. Inspect the basic fuel supply side first: fuel level, air in fuel, water contamination, clogged fuel hose/pipe, and clogged fuel filter. [3]
3. Inspect for external fuel leakage at the high-pressure side, especially loose injection pipe retaining nuts or visible leakage around injection pipes/rail/injectors. [3][4]
4. With KOBD ACE, monitor target rail pressure versus actual rail pressure during the condition that sets the code. P0093 is set when the ECU judges excessive fuel loss/pressure deviation in the high-pressure system. [2][5]
5. If supply-side and external leak checks pass, continue into fuel-system component diagnosis: injector leakage/sticking, supply pump/SCV operation, rail/rail pressure sensor feedback, and harness/connector condition. [2][5]

• Step 1: The MX5200 WSM lists P0093 as “Fuel leak (in high pressured fuel system)” with SPN 1239 FMI 1. The diagnosis manual also states P0093 is evaluated only when P0087, P0088, and P0089 are not present, so those codes can change the diagnostic direction. [1][2]
• Step 2: The MX5200 WSM fuel-related troubleshooting list includes empty tank, air in fuel system, water in fuel, clogged hose/pipe, and clogged fuel filter as causes that can create fuel delivery problems. These should be ruled out before condemning common-rail components. [3]
• Step 3: The WSM specifically calls out fuel leakage from a loose injection pipe retaining nut as a possible fuel-system fault. A real high-pressure leak can trigger P0093 and may also cause poor running or no-start symptoms. [3][4]
• Step 4: For the V2403-CR-E4 / V2403-CR-TE4 diagnosis manual applicable to this engine family, P0093 is based on the ECU detecting that actual rail pressure is not matching desired rail pressure under full pump supply conditions. The manual lists the set parameter as deviation between actual and desired rail pressure greater than 20 MPa for 60 seconds or more. [2][5]
• Step 5: The DTC preconditions state the ECU expects normal battery voltage, sensor supply voltage, rail pressure sensor, supply pump/SCV, injector and injector drive circuit, and NE signal before setting P0093. If the simple checks pass, the fault is likely in fuel quality/supply, injector leakage, supply pump/SCV control, rail pressure sensing, or related wiring. [2][5]

• Is P0093 active immediately after start, only under load, or after running for a while?
• Are there any companion DTCs besides P0093?
• Does the engine derate, stall, or just turn the warning lamp on?