3406e fuel problem

Don't know if the 3406Es use the same injector setup as the C-15, but when I had an injector hold-down bolt break on my C-15, it allowed the fuel system to lose pressure, and WD-40/starting fluid was the only way to crank it, and keep it running. You mentioned recent injector work, and that recent experience popped into my mind, if the setup is identical, were the hold-down bolts replaced?
Good luck, and hope it's something cheap.

 

Strangebrue-Pullingtrucker's post about the batteries not being strong enough to run the ecm and the starter reminded me of a problem I had with my old pickup. You could turn the ignition switch to the "on" position and roll-start it just fine, but it wouldn't hit a lick with the starter. Turned out to be the ignition switch not powering the coil with the key in the "start" position. Anyway, I know that's on a gas engine, but it sounds like your fuel pressure isn't leaking down now, so I would think that there is still a possibility that the ecm isn't getting juice with the key in the "start" position. Would be pretty easy to test, just hotwire the starter with the key in the "on" position. Sorry if you/Cat already tried this. Found this looking for some info on my air compressor, guess I'll get back to it...

 

I know this seems like a crazy idea, but being an electrical issue might explain it being sporadic, starting for CAT and not you the next day.

 

Something you might want to look into is the sensor on the back of the cam gear cover I think it is a Rpm sensor (not sure) Had one of those with a bad wire that gave me the same sort of problems that you are having.

 

Sounds to me like your primary filter sucking air or leaking back, some primary filter bases crack internally and let the fuel run back, some filter bases require you to put and o-ring on top of the filter to seal them to stop the fuel running back. There is a Cat publication regarding this but the Cat shop should know about it (SEBD6813 is the number if they cant find it).

 

Strangebrue, let us know what it is when you figure it out, I'd like to know for future reference.

 

having kind of same problem with cat 3406 , will not build up enough fuel pressure to start have to spray starting fluid and it cranks and runs great . kill it for two minutes and you have the same problem once more ,primer pump builds pressure up and it runs back down soon as you stop pumping . just want to fix problem before starting fluid causes more problem . need to find check valves and check them out first , will try that today . any body has idea just in case this is not it tell me . THANKS

 

number 5 is your fuel pressure regulator (aka) check valve.

 

Had same problem on a 3406 e it was the fuel pressure line from filter to Guage in cab was cracked. No external fuel leak.