Hi im actually in Nunivit right now and its freezing here at work so i could use as much info as possible.So whats happening is the backhoe will start and run for 2 mins then start to have an erratic idle "like starving for fuel " and then stalls. i have to cycle the key or just wait a few minutes before it will start again. Then it repeats this over and over very consistent with the run time always 2 mins same symptoms. so here is what ive done so far,i disconnected the main feed line at the injector pump and placed it into a gas can of fuel hoping i could eliminate the fuel system and tank for icing or debris. ran the same.then i checked power going to shut off solenoid it had 12+v and monitored it when it stalled voltage never dropped. Im at a loss right now for what is causing this and im leaning towards electrical because its so consistent and stall times and startup. the only thing i haven't checked was for blockage in return line. Would this cause these symptoms? Also im literally in the middle of nowhere and do not have access to a diagnostic scan tool for codes or a fuel line pressure gauge which im sure would be what i need to further investigate. Can anyone help? maybe similar experience with these machines or common failure thanks so much
Not familiar with a cat what so ever or if the return line could cause that. To check take the return line off if possible and let the excess fuel squirt into a can & see if it stays running. I don't think it would start if you had a fuel pressure problem. Try switching around a couple of the relays that are compatible, nothing to loose trying. No tiger torch or stove pipe to get some heat under it for an hr. or so? Freezing temps can cause a lot of mysterious problems. Feel for you and sorry I'm of little help.
Yes, a blocked return could cause those symptoms. I don't know a 420e or more importantly which injection pump it has, but that's a common enough problem. Do like Billrog says, you might have to take off the FITTING from the injection pump so you can see right in there, check that fitting for blockage and report back. You can check the solenoid electrically by taking an ohm measurement cold, and then immediately after disconnecting the line with the key on after it's died. SOMETIMES coils will fail hot and work cold, but that's not a typical way to go, too consistent for electronics IMHO.