D6n xl

Someone may have the answer off the top of their head but if you want to trace it yourself send me a PM via the "conversation" feature with your email address and you can have an Electrical Schematic for the machine.

Thanks Nige, I had one just had to find it. cat doesn't make their schematics easy to read. It was just a command ground. Still have a no start without a little shot of either, have ran ever test from the trouble shooting manual. No warning lights no error codes and no event codes. Thought maybe the supply pump may not be putting out enough fuel just turning it over so i turned the electric primer pump on while cranking engine, still no luck. Hate to call cat people down It is 11 hundred dollars just to get them to location.. Thanks Nige

hi ,there are a few simple things that you can do before you need ET
check your cranking speed ,no less than 150 rpm min
check that there is no fuel dilution of crankcase oil which would indicate an internal leak, which is usually where injector fuel line connects to injector
be very careful with this one .remove the return line from the high pressure relief valve cap the line and obserb that there is no fuel coming from the relief valve while cranking .this is a no leak valve and nothing should come out
check the injector return line for excessive leakage.YOU CAN DO THIS WITHOUT CAT TOOLING IF YOU UNDERSTAND WHAT IS GOING ON.
Disconnect the injector harnesses, remove the injector return line from back of head cap the line and make up an adapter that can screw into the head with a hose that can be placed into a graduated container. crank for thirty seconds and check how much return fuel is in the container .Should be no more than 38ml and in practice much less than that. anything approaching or over this limit would indicate faulty injectors giving you low rail pressure a hard start condition.
the fuel lines on these engines are designed for single use only. if you undo them and try to reuse, you can introduce bits of fuel line into the injector which can cause problems (the high pressure seat is designed to deform under compression to seal the very,very high injection pressure involved
I am thinking that this is what happened in your case
top photo is of high pressure reiief
bottom photo is of injector return line

Thanks Mark. Replaced #2 fuel line but did not loosen it after installing it. Cranking speed is 172. Washed engine and ran for an hour and can not find any external leaks. Already pulled the line from the high pressure relief valve. No leakage. As far as I can tell there is no fuel in the oil. Maybe some of the old line went into the # 2 injector when i changed the new line. I know where the return fuel line is at the back of the head, so i will check the return fuel. 38ml is about 1.3 ounces. I will unplug all 3 injector harness to see what happens. How will I know which injector, if any. I would think it would be #2, since it was running fine until the line blew out. Thanks again.

very complicated procedure and expensive from cat as they use test fuel lines and adapters. as I said in earlier post once you undo those lines you are up for replacement six new fuel lines plus test fuel lines plus adapters gets expensive unless you are doing it all the time
in your case you would suspect the injector that was involved with the fuel leak
has any other work been done on engine ie valve set etc because there is a special procedure for valve set on these engines and if you get it wrong you can bend valves or push rods
one thing I forgot to mention earlier have you tried to start the machine with the primary speed sensor disconnected the one on the block. if it starts pull the sensor and gently probe through the hole and feel for the sensor ring they have been known to come loose
Mark
.

Thanks Mark. New fuel rail pump about a year ago. And that is it besides the line. I already had pulled the primary sensor and checked the ring on the flywheel. No start. It has been running fine Until the #2 fuel line blew the end off at the fuel rail. My brother and friend put the fuel line on while I was away. probably didn't clean anything I would think, knowing those two. Hasn't started since the fuel line was replaced without a shot of either. The machine had code 0261.11 since before the fuel rail pump was replaced. I didn't check to see if the large tab was in the sensor hole when I replaced the pump a year ago because the pump was pined when we bought it. Will know better next time. I pulled the rail pump wednesday and corrected the timing. Code is no longer active. Have no active codes or events and no warning lights. Checked the supply pump for pressure 80 pds or more while cranking. headed out this morning to check the return fuel. One more thing, while i was using the electric primer pump I think I hear kind of a whistle sound coming from about #2 injector under the valve cover. Thanks mark

Update for you guys. Did as mark said and capped the fuel line and made a connection to let the fuel run into container and unplugged the three harness wires.. No fuel came out from the return on the head. Did check the fuel pressure on the low side again just to make sure it was feeding the rail pump. have Ran every test I can find. Went all the way thru the no start trouble shooting manual and the service manual. Told my friend to buy a can of either or get someone smarter than me. He said no we will work on it till one of us dies, he is 62 and I am 67. LOL!!!! I failed to mention that I am not a novice. I have worked on lots of trucks with command fuel rail systems. Worked for an oil field company for 30 years, Changed the wiring harness under the valve covers many times. Just never worked on newer model dozers. Lots of repair time on New Holland skidsteers with common fuel rail systems, but this one may drive me to drinking. If anyone has any suggestion I will give it a try. Thanks again for all your help.

should of asked earlier in the post. how does the engine sound while running, is there a stumble under acceleration. have you used a heat gun on the exhaust manifold runners still sounds like low rail pressure to me can you verify that the injector line is seated correctly in the injector by visually removing rocker and checking

Mark250 said:

should of asked earlier in the post. how does the engine sound while running, is there a stumble under acceleration. have you used a heat gun on the exhaust manifold runners still sounds like low rail pressure to me can you verify that the injector line is seated correctly in the injector by visually removing rocker and checking

Click to expand...

Mark I haven't pulled the valve cover to look for leakage. I agree it sounds like low fuel rail pressure, since it starts with a little shot of either. And it does have a little stumble between 1200 and 1600 rpms and i think I see a little grey or white smoke until it warms up. I will pull the valve cover and take a look today. Care to explain (exhaust manifold runners). Thanks again Mark

Bo McCoury said:

Care to explain (exhaust manifold runners). Thanks again Mark

Click to expand...

sorry, just my way of saying check the exhaust temp at each out let of cylinder head. a lot of engines have a short piece of cast before the enter the exhaust manifold proper this is what I call a runner
sorry for the confusion
Mark

Mark250 said:

sorry, just my way of saying check the exhaust temp at each out let of cylinder head. a lot of engines have a short piece of cast before the enter the exhaust manifold proper this is what I call a runner
sorry for the confusion
Mark

Click to expand...

No problem I will check it. Thanks

Just wondering what the voltage would be on Fuel rail pump solenoid while cranking. I guess should get a code if voltage was to low or to high. i think I see a little fuel seeping from under that solenoid. Used air today and blew it off several times and the fuel seeps back again. Thanks guys. Well off to store to get a fifth of Old Crow. Don't drink, but going to get a head start just in case I decided to start. LOL!!!

Bo McCoury said:

Just wondering what the voltage would be on Fuel rail pump solenoid while cranking. I guess should get a code if voltage was to low or to high. i think I see a little fuel seeping from under that solenoid. Used air today and blew it off several times and the fuel seeps back again. Thanks guys. Well off to store to get a fifth of Old Crow. Don't drink, but going to get a head start just in case I decided to start. LOL!!!

Click to expand...

The ECM supply's a pulse modulated signal to that solenoid it is also a non serviceable part .the only parts serviceable on the pump are the transferee pump. the speed sensor and the two high pressure check valves under the angled hex heads.
after the injectors have been eliminated as a source of high pressure loss, it is usually recommended to replace these check valves before pump replacement usually as a last resort
how did you go with the heat gun and visually confirming no fuel leak into the engine lube oil

Did not check the manifold yet, didn't have heat gun yesterday, but it has a solid manifold. I did not find any leaks under the rocker cover. Yes I knew the solenoid is non- serviceable. I was just wondering about the voltage at cranking speed to the solenoid. I know the voltage varies depending on the engine need for fuel. Volts is 6.2 at cranking speed. Thanks mark

Update for you guys. Fuel rail pump is seeping fuel from under the fuel rail pump solenoid. Blew it off with air several times and it keeps coming back. Thanks