Well, in my 38 years of being in this business.........I ran into a FIRST today.
Cat 299D.......FKM went out on this machine Tuesday for a no start. Replaced a fuel pump that I had already replaced in January (He didn't know, but I don't think he troubleshot this properly anyway) which didn't fix the problem. After 6 hours he gave up.......that is when I was called.
I get there yesterday and after a few minutes I find the ECM fuse blown. I Installed another and it immediately blew......went 5 amps higher.....another blow. I have a super hard short somewhere, so I get the cab up and just as I start troubleshooting, a paver goes down across town. I have to pull off this loader, tell the job super about the paver emergency and off I go. The super says he needs the loader so I tell him I will call Cat field service and see if I can get them out since I have no idea how long I may be. It will be the following morning.
Cat FS tech calls me on his way to the loader, I fill him in on what I know.......he will call me when he finds the issue. 5 hours later I have another paver go down on the job where the loader is. I get there and stop where the Cat tech is to check on the progress. He's flustered pretty good. Said he did find the short on the engine harness and now the ECM is coming on.........but the engine still will not start. No codes after he cleared all of them. He calls 2 other techs for ideas as what to check for. He does a little bit more electrical checking and the job super walks up.
The job super tells both of us a different story than the operator did. The operator said the engine just died. The super said it was running when they started putting fuel in it and that's when it died. So the 3 of us are thinking they either introduced water into the fuel, or DEF.........but since FKM was there first, we couldn't determine if any water had been drained off the filters and could find no evidence of it. No evidence of DEF either.
So, while the 3 of us are standing there thinking of what to do next, I told the tech that we could try a shot of ether. I mean why not.......at least we would know a few things if the engine kicked. We all agreed to try it so I removed the air cleaner lid and the primary filter.
Look at this sh*&..........................
Someone stuck the freaking secondary filter in backwards choking the air off to the engine. I think all 3 of us said "WTF!!!????" at the same exact time. Flipped it around and the machine started right up. I can't find anyone willing to admit they pulled the filters and put this in backwards. We stood around another 15 minutes laughing our asses off about this entire scenario. All of us took remembrance pics.