Have a pc 45 mr-5 that will crank over but won't start. Did get it started for about 15 to 20 seconds , but then it died. Ideas of what it could be? Doesn't have a dedicated fuel shut off valve. Electronically controlled on and off. Have replaced many parts that I thought it could be. Fuel pressure regulator , pressure relief valve , pressure sensor , fuel filters , and injectors. Lift pump is tested and good. I don't think it has any fuel line air leak. Thank you for any help/ideas. I don't have repair manual.
Were all these parts OEM or were some aftermarket. You have spent a lot on these parts, was a gauge ever hooked up to this unit. Does it have an air shutoff that is tripped. Have you tried for a few seconds to see if it fires on starting fluid. Does it have external fuel lines to the injectors or are they within the valve cover. Have you tried running it off an external Jerry can of fuel.? Not sure if it has a fuel solenoid. Is there any smoke out the exhaust. How many hours on the unit. Did a mechanic suggest all these parts or was it just an attempt to make it go. Is there any o-rings missing on the filters so that it could suck air instead of fuel. Is there any codes on the dash that could tell anything. Do you have a multimeter for testing? We are not there so can only ask questions. Simon C
Have you checked all the fuses and relays for power, probably not if you don't have a manual. If you post your serial number you might be able to get more information like a schematic or some test info. Simon C
Thank you for replying Simon. You triggered my memory on a few things. Alot of aftermarket parts. It does not have a fuel solenoid. I drained fuel tank. Changed fuel filters twice. fuel lines were blown out. Fuses and relays were checked. ok Tried starting fluid which I hate doing. External fuel lines. No fuel is getting to injectors. serial #30681. A little smoke out of exhaust prior to emissions stuff to see if there was any smoke. Mechanic was a Komatsu dealer technician with help from his supervisor. I did have a p0093 code and a p0094 code. Supposedly all those codes are not popping up anymore. I will probably need them to come out to hook up machine to computer again. Unfortunately 8 to 10 hours and got no where. Thank you
A guage was hooked up. He was only getting about 1000 psi pressure or there abouts. He thought it was an injector or multiple injectors because he shut off injectors thru computer and got a little smoke out of exhaust that was disconnected at the emmisions. They couldn't get injectors out so they wanted to pull head and pound them out. I got the injectors out. I just decided to purchase aftermarket injectors instead of spending $5000.00 on oem and probably not going fix the issue. I have about 3800 hours on machine. Thank you again
Can't say too much good about aftermarket injectors from my experience. How do you know if the computer is not being told not to make engine go, what kind of electrical testing was done for computer power in and out. I have seen a Dodge Ram Diesel that ran like junk that needed new battery positives and all the ground cables. It needed injectors according to the owner until I changed all the cables which were no longer available so I built them. There is a lot of things that make an engine like this run, doing a thorough testing of all the electical along with all the fuel system would be first. Could even have a failed sensor that is producing no codes. Maybe someone else will chime in with some more hands on for that unit. Does it have a Komatsu engine or what kind? Simon C
Simon That is why I think I need to have Komatsu mechanic back out. I indeed think the computer is telling it not to start. Just my guess. I was hesitant to use aftermarket injectors , but hate to put oem injectors in and still not have it run. Yes , it is a komatsu engine 4d88e-7 but produced by Yanmar 4tvn88c.
Did the Komatsu mechanic do all the electrical testing first along with checking codes, cause lets face it if there is anything wrong electrically to the computer control, you don't need any of the other parts until the computer sees clean power in and ground along with quality crank sensors or cam sensor information. Injectors and computers do not run well with poor connections somewhere. Don't be surprised if you get grief over the aftermarket injectors from the Dealer mechanic. You changed a lot of fuel pressure related items and it still will not start, tells me something is being missed. He has the schematics and technical info if he knows how to use it. Everything tested needs to be recorded for the next guy that will work on it. Fuel lines blown out is good but is there a banjo bolt or screen in one that is plugged. Someone is not thinking for all the money you have thrown on it. Did he even test the computer power in and out wiring. If you installed more than the injectors aftermarket, you may not ever get it going in my opinion. Too many stories on this forum about faulty sensors that sent people down rabbit holes. You need to make a list of exactly what is what for the next guy coming on the job. Simon C