D6k2 xl cranks but don't starts

[kshansen]

We have given you suggestions and you haven't returned any answers or results from those suggestions. I doubt anyone is going waste anymore time trying to help you if you're not going to follow their input.

I have to agree with newguy2k3, seems like in place of a conversation where someone suggest "Try this and see what you find" expecting a reply to help the person who suggested it to know what the result was so they can understand what is going on.

Instead seems like the original poster keeps trying things and saying it worked for a short time then nothing works again. Sometimes one can get lucky and stumble on to the solution to a problem but that is not often the best way to find the real problem.

One also has to understand that the people trying to help are not there and can not see hear or smell what is going on. The only thing we have to work from is the replies of the person who IS THERE!

I would suggest the original poster to print out the Cat troubleshooting chart I posted and start at the top and do each step one at a time and report back on the results.

 

[Dgze]

Dear newguy2k3.sir I have followed each and every instruction problem is this when u guys commint there is night or I am on machine that's why I rply late otherwise I really find helpful your every suggestion.1 when machine started on either it's runs fine smooth how long u want to work there is no problem but if u off ignation switch after that machine don't start without either in hot or cold no matter.i have removed both filters checked the tube it's clean also checked turbo charger it's also in good condition.
Here is my whatsap number if u can text me or call me any time
00923337984294

 

[Mobiltech]

I think you might have a high pressure pump problem. Usually when you start replacing injectors the pump should be replaced too.
I have had both injectors and pump cause the hard starting you have. Et would help so you can monitor fuel rail pressure.
I would talk to your cat dealer again and see if they can test it for a bad pump. Sorry but these engine can be costly to repair the fuel system.

 

[newguy2k3]

I think you might have a high pressure pump problem. Usually when you start replacing injectors the pump should be replaced too.
I have had both injectors and pump cause the hard starting you have. Et would help so you can monitor fuel rail pressure.
I would talk to your cat dealer again and see if they can test it for a bad pump. Sorry but these engine can be costly to repair the fuel system.

Ideally I'd like to know cranking rail pressure and the results of an injector leakoff test but this seems like the next logical part throwing step.

 

[Dgze]

Dear kshansen sir I followed the chart send by u and thanks for helping me I have test everything but compression tester is not available there.fuel pressure is 40 psi cranking speed 167 n/min.air inlet turbo all clear.there are no diagnostic codes speed sensors crank and cam changed fuel rail pressure sensor changed relief valve changed vavve adjusted tomorrow only compression test is left due to not avalilablity of tester.injectors also changed

 

[Dgze]

Newguy2k3 sir I have changed all 6 injectors+ sensors related to starting .I think rail pressure is ok coz I disconnect rail pressure sensor line and cranked machine it shows high fuel rail pressure.and I also checked pump pressure with pressure guage it's 40 psi and cat says 40 psi for c7.1 engine is enough for starting any thing else u want to check I am ready to check and inform u

 

[newguy2k3]

40psi is the supply pressure to the high pressure pump. The output from the high pressure pump should be 3600psi+ and it needs to be checked with ET.

 

[BigWrench55]

If you can get it to run with ether and it stays running until you shut it down. Then you are losing prime in your fuel system. Either the relief valve is dumping the pressure or the check valve on the back of the head where the fuel return line is has failed. Hard to diagnose without catE.T. Or understanding how the fuel system works.

 

[newguy2k3]

If you can get it to run with ether and it stays running until you shut it down. Then you are losing prime in your fuel system. Either the relief valve is dumping the pressure or the check valve on the back of the head where the fuel return line is has failed. Hard to diagnose without catE.T. Or understanding how the fuel system works.

You're thinking of a c7 heui engine. This is a c7.1 common rail.

If the ECM does not see at least 3600 psi of rail pressure while cranking out will not even try to fire. Usually it's the injectors leaking off excessively that cause low cranking pressure. I'm guessing the ether is giving just enough extra cranking rpm to get the rail pressure high enough to fire and run.

 

[Dgze]

Dear I have changed injectors they only runs 50 hours

 

[newguy2k3]

It's possible that the high pressure pump is what has been failing all along and caused the other injectors to fail.

 

[Mobiltech]

It's possible that the high pressure pump is what has been failing all along and caused the other injectors to fail.

This is exactly what I’m thinking.
unplugging the rail sensor is not going to show you that the pump is good. Without a sensor the ecm has no clue what the pump is putting out and it will cut pump signal altogether. The code will be sensor high current while it’s unplugged.
I hate to say it but you’re probably going to need a pump. I give it about a 10 percent chance that compression is the problem. If it had low compression it would be smoking blue after an ether aided start.

 

[thepumpguysc]

screw it.. ya got 32 questions & no answers.. u can BUY a WHOLE LOTTA starting fluid for the price of a pump & injectors..AND the cost of the Cat techs coming out & replacing parts..LOL..

 

[Dgze]

Fuel pump supplies 40 psi to secondary fuel filters this presupre goes into rail continuesly and relief valve hold it to 36000+- psi .if it's above they requeired pressure sensor must sense that pressure and ECM detect high pressure or if it's not building enough pressure ECM also detect low pressure if I'm understanding

 

[Dgze]

Thepumpguysc sir it's really complicated without ET but we have to diagnose it

 

[kshansen]

Thepumpguysc sir it's really complicated without ET but we have to diagnose it

Did the Cat guy not have ET? Did he actually check anything? Did he give you a written report as to what he had found?

 

[newguy2k3]

There are 2 seperate fuel pumps. A low pressure transfer pump pulls it from the tank, pushes through the filters to the high pressure pump.
That is the 40psi you're getting.

The high pressure pump turns that into 7-30,000psi and sends it to the injectors. This pump HAS to make 3625psi before the engine will even try to fire on its own. This is the number that's important and that you cannot see without cat et.

 

[kshansen]

There are 2 seperate fuel pumps. A low pressure transfer pump pulls it from the tank, pushes through the filters to the high pressure pump.
That is the 40psi you're getting.

The high pressure pump turns that into 7-30,000psi and sends it to the injectors. This pump HAS to make 3625psi before the engine will even try to fire on its own. This is the number that's important and that you cannot see without cat et.

That is what I was trying to get across back in post #16 way back that if you are going to be running a new machine like this you have to either get the proper tools to work on them or have someone you can call in when a problem rears it's head.

One minor problem with a bad sensor and a machine can be dead in the water with out ET to calibrate something.

We learned that years ago with a 988H minor problem of sensor bracket bolt broken. Replaced the 3 12 mm bolts figured it was good to go. Nope, sensor had moved past it's normal range and needed to be re calibrated. No damage to sensor but the main production machine for the plant was down till dealer came out and spent five minutes with laptop! Problem solved!

 

[newguy2k3]

That is what I was trying to get across back in post #16 way back that if you are going to be running a new machine like this you have to either get the proper tools to work on them or have someone you can call in when a problem rears it's head.

One minor problem with a bad sensor and a machine can be dead in the water with out ET to calibrate something.

We learned that years ago with a 988H minor problem of sensor bracket bolt broken. Replaced the 3 12 mm bolts figured it was good to go. Nope, sensor had moved past it's normal range and needed to be re calibrated. No damage to sensor but the main production machine for the plant was down till dealer came out and spent five minutes with laptop! Problem solved!

In this case with the rail pressure sensor unplugged it would throw a voltage above normal fault but the engine should still run. It would run on a "default" fuel rail pressure control map and be derated. If everything is mechanically fine it should run.

 

[epirbalex]

Dear I have changed injectors they only runs 50 hours

Pretty soon your pump will be stuffed if you keep poking paste through it to your nice new injectors , thats if you pump is not stuffed already , which I think it will be . It will be crook fuel that is stuffing them , if they are , indeed , stuffed .Hopefully its a partially blocked system and not a destroyed pump which will be costing big money .