I just purchased a 2005 Pete 379 with a c15 acert. It will not start without a little ether. After some research I read that a common problem was the check valve in the filter head. I’ve replaced both check valves twice with no luck. You can hand prime the pump and you can hear the fuel returning to the tank and it never gets stiff. You can also crank on it and hear it returning into the tank. I have put a fuel gauge on it and I’m only getting 10-15 while it’s cranking over.
Search the Adept Ape channel on You Tube...everything Cat, this problem sounds like something he has covered before...
Been on his site considerably Saved me a load of digging work and bugging all too many people.
There is a pressure relief valve that goes in from the bottom of the filter head, it should be right in front of where the return line leaves the filter straight up from the bottom. Pull it out and inspect it, it may need to be replaced if it is stuck open but that sounds like the issue if it won't build pressure with the hand pump. Usually you can hear it squeak when it relieves while hand pumping.
This is what it looks like, could also be a bad oring on it.
Yes sir, I have replaced this twice as I was told on another forum I could have bought a bad one. What doesn’t make sense to me is why it’s returning to the tank so easily
That makes no sense to me either, as far as I know that is the only restriction in the system that makes pressure. I will have to do some thinking on it.
I capped off the line coming from the back of the head that goes back to filter housing, cranked it over and I’m still getting fuel returning to the tank? Would this indicate a internal crack on the filter housing? Could it be leaking by on the hand primer?
Those hand primers have a check valve also, the check can roll partially over and cause all kinds of anxiety. Especially the short stroke model.
I pulled the filter housing off and removed everything from it and found what appeared to be the “bleeder bolt” to be missing an oring on the tip of it. I put an oring on it and now I’m building 35-45psi while cranking but it still will not start without a little shot of ether
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Update- i took the filter housing completely apart, cleaned and inspected everything and put an oring on the end of the bleeder screw. I was getting better fuel pressure but only running about 65-75 at idle. I put clear hoses inline to make sure I wasn’t sucking air and getting adequate fuel to the transfer pump, nothing changed. I put a new transfer pump and now I’m getting around 70 psi while starting but it will not be crank. I can spray the slightest amount of ether and it fires right up, it doesn’t smoke or anything. With the new pump I’m getting around 90 psi but it is very sporadic my fuel gauge needle is jumping like crazy. (Did this with old pump also) I’m lost. What can I check now? Isn’t much left expect injectors.
Thinking back-about 12 years ago we took care of a small fleet of grain trucks. I've only seen this one time and happened on one of those grain trucks. Mind you It baffled the hell out of Gayle {the other mechanic} and I. The engine was a 98 6TS 3406-once running it was fine, but would not start without ether. Gayle and I went through the fuel system-I had a used cam sensor {this one screwed into outside area of front structure} It fired off. This engine never threw a code. We figured the sensor was giving a weak signal on just cranking-that was our best guess. It's still running today on that used sensor. I'm not going to say that's your problem-just one I ran up against.
there is a remote possibility the oil pressure sending unit is getting weak also. had one of ours act very much like what is being described. non start with out a little shot then went to limp mode turned out op sensor was bad
even if the gauge is showing oil pressure while cranking?
I’m g im going to try and find someone with cat ET to hook up to the truck
yes it would show pressure. this went on for some time i really can`t explain it but it would start and run fine did this 7-8 times then went limp mode` diagnostics told us op sensor replaced that` problem went away
C15's can be picky if they have a wonky (technical term) timing sensor, the no start even with good pressure till you give it a lil shot of start in a can is a common symptom of one or the other not working right. Won't always get a code either.
Series 60 it's called a SRS {synchronization sensor} sometimes those will cause a extended crank time the next time start immediately.
Oil pressure gauge in the dash has a line to the motor, there is a separate pressure sensor that the computer sees. Et will show what it is seeing as well as cranking speed. Sometimes they will throw a code that is too momentary to store but will be there causing the problem. With et hooked up it will show the active code when it occurs but when it starts it will go away.