Hello We have a Volvo 29 ton excavator with a D7 engine I believe Middle of shift it just lost power It starts and idles for a bit but when you go to rev it up it’s like it’s starved for diesel and cuts out The odd time it won’t even idle it just starts and cuts out But it starts everytime as normal Replaced the Low pressure pump driven by fan the belt Replaced the two high pressure pumps The Fuel control valve Rail sensor Pressure sensor Swapped injectors from another motor Still doing the exact same thing The fault on Techtool is psid 96 rail pressure system fmi 12 Would appreciate any help or advice
So, to be clear, you have a 290BLc tier III? You've replaced everything? Did you inspect your fuel water separator? Is it a factory Volvo filter? Is the bowl sucking air? Which filter head do you have on the separator? Is it the piston pump that unscrews or the diaphragm plunger?
What do your fuel lines look like? Any getting pinched from tools thrown where they don't belong?
Proboby your problem is electirical, control alternator if you have a change replaced the alternator and test machine again.
Hi all Thanks for your help We replaced the main fuel filter housing and the machine is back working perfectly
Hello I am glad your problem solved.
I got the same psid 96 fmi 12 on ec250dl (vcec250dp00220391) with d8h engine. Evenlope flashes without pattern but only when engine is at operating temperature. Low fuel pressure at idle 6.2bar, with load it drops to 5.6bar. Rail pressure 550 and 1350bar. Dealer is giving up and have nothing more to say so will not come anymore. Replaced: Fuel lines Fuel water separator (piston pump), oem filter Fuel supply feed pump (gear), oem Fuel filter housing, oem filter Fuel low pressure sensor, oem FCV, oem HP pumps, Bosch HP pump lifters (don't know how it is named by mechanics), oem PRV and rail pressure sensor, oem Injectors, Bosch Injector fuel delivery tubes, deutz Injectors sleeves, oem Engine wiring harness, deutz So.. Who likes challenges?
Telling these guys that the dealer has given up...you just threw down the gauntlet for these guys!
I find low side fuel pressure suspect. I don't like the idea that it's dropping off. That said, your 250D is a completely different animal from the 240B. Would really like to have seen a new thread so you could get appropriate guidance. That seems to be a waste of time. So here goes. A properly running machine, the low side fuel pressure should not drop off from full throttle no load to fully loaded. I would run the tank dry or drain it. Pull the sump plate and look at the strainer screen. See if it's a solid block of rust. Then remove the fuel line from the new filter head. Blow it clean from the filter head back to the tank, see what comes out. Did the dealer perform any actual testing or did they just change parts out of lack of knowledge? Good luck.
I wrote here because of the same DTC, sorry. With so much done, I forgot to mention that the sump plate was removed, inspected (nothing interesting found) too. As I made new fuel lines, I did not blew that with air. Sieve in the filling tube and tank cap are both quite rusty, so it is possible that there are some of it in the elbow on sump plate? Fuel tank breather filter replaced too. Also - there is no power loss or derate, no black smokes. Dealer performed fuel supply pressure mechanical test and measured returning fuel quantity from injectors. Also used tech tool to check and compare pressures in it and i-ecu monitor. They have not tested any voltages or resistances.
FMI 12 indicates something isn't responding properly. ie. Rail pressure command is 500 bar, and you're system, maxed out only produces 450 or on the opposite end won't drop below 625. Its not sensing a wiring fault or getting bad feedback from the FCV. It just says, I'm asking for x and getting y. We have to look at all things mechanical. First things first. I'd replace that sump strainer. Start at the beginning. Second, and this is a hard pill for many mechanics. New doesn't mean good. Just means it "should work" and carries a warranty. I would measure your rail return separate from FCV return and also separate from injector returns. WHEN ITS WARM. You could have an injector that's dumping rail to tank but only when it's up to temperature. Finally if none of that pans out. Take one of your old injector feed lines, cut the pipe out of the middle and weld them shut. With this, you'll be able to mechanically remove the injector from the fuel system one at a time. Figure out which one is causing your grief. Good luck
Given your diagnostic code and the extensive parts replacement already performed, you are likely dealing with a mechanical failure that bypasses the high-pressure system or a communication breakdown between the ECU and the fuel components. The code PSID 96 FMI 12 on a Volvo D7 engine indicates that the Rail Pressure Control is not working correctly. Since you've replaced the pumps, sensors, and injectors, focus on these remaining critical areas you can see complete repair guide for the EC290BNLC . Identify these points: 1. Pressure relief valve (PRV) failure 2. Restrictions in the low-pressure fuel circuit 3. Communication between the wiring harness and the ECU 4. Small return valve
4. Small return valve Where is that?
hi, Main Control Valve (MCV) Area: The valve is often assembled in a pipe or line close to the main control valve. Return Line Assembly: Specifically, it is located in the pipe (line 2 in the service manual diagrams) that runs from the main control valve to the hydraulic oil cooler, before the oil goes to the tank. Physical Description: complete repair guide for the EC290BNLC Service manuals list this component as a “check valve” (part number 14573209 or 14673207, with a pressure rating of 3.0 or 4.5 kgf/cm² respectively). It is a small, one-way valve. Fuel System Context (if applicable): A different “small return valve” is also present in the fuel system, located on the front of the cylinder head. A malfunction here causes fuel to return to the tank, leading to starting problems.
Create a new thread so we can document this like should be done. Then maybe we can help you.