2005 caterpillar 950gII

[4digger]

Hello. I am working on a caterpillar 950g. It had a bunch head issues that are fixed now. But the loader will not fire. We've put a new injector wire harness on timing sensor oil pressure sensor. Two new injectors a new transfer pump. Prior to doing the head work the loader would start but run rough and smoke a lot due to engine oil getting into the cylinders. Does anyone know how to clear the codes without having to call cat to plug into it with a computer? I'm thinking it threw a code that won't let it run now. Thanks in advanced for any info.

 

[big ben]

Nothing needs to be "cleared" to get it to run. If there is a problem or reason why it wont fire its because all the problems are not fixed. When they are fixed the "active" codes or events will move to "logged" codes or events and not effect its operation

Does it turn over ? Is the ground level shut down tripped ? Also not sure how lots of engine oil would get into the cylinders. Lots of fuel yes but oil ?

Air in the fuel system that is not bled through yet causing it not to start ?

 

[4digger]

Hey Ben thanks for the reply. Yes the engine cranks. I'm not familiar with the ground level shutdown. It was a combination of bad valve seals and injector o-rings that letting oil pass into the cylinders. It wasn't loads of oil but enough to cause problems. When we got the engine back together it ran but no power now it won't fire at all. I was thinking a code would stop it because it's acting like the injectors arnt firing.

 

[big ben]

Well on the same screen as the hr meter reading it will say "active code" or "code" if there is active codes. Press the info button to scroll through all the active and logged codes. Note only the active codes will say "active code" or "code" as it displays them one at a time. There may be lots stored but we only care about the active ones right now. Write them down and post them and people can explain what each one means and if it's the problem.

Sounds like a fuel issue though. Can you hand prime it or turn on the electric primer does it fire again ? Are the fuel filters full of fuel after it was running ? Fuel shut off half closed ?

And the ground level shut down is a switch under the red cover - maybe by the boarding ladder or rear of the machine. If its tripped it disables the injectors

What engine is in it ? HEUI ? Was there a failure in the HEUI system that made the injectors fail ?

 

[Nige]

Give us a machine Serial Number so that the correct engine info can be supplied. As Ben pointed out there are a lot of different engine options that a S/N would narrow to just one.

Confirming what Ben said, there is no Diagnostic Code that would stop this engine from starting, so it appears that the problem for which you tore the engine down is not completely fixed yet.

If it is a HEUI engine then here's how the system works to light the fires from cold. The ECM monitors the hydraulic pressure at the Injection Actuation Pressure (IAP) sensor. The ECM calculates a "Desired Actuation Pressure" and compares it to the IAP pressure reading. Once the IAP reaches or exceeds the Desired pressure the electronics activate the injectors and you get smoke out of the chimney.
If you are getting no smoke at all then the causes could be slow cranking speed (you need 150RPM as an absolute minimum), oil leaks within the High Pressure side of the system that prevent the pump generating sufficient pressure (possible as you have had the whole system apart by the sound of it), leaking injector poppet valves (try cranking the engine with the valve cover off and look for oil spilling out of the injector exhaust port hole), or a bad HEUI pump (v. expensive). Or, even more expensive, a combination of all the foregoing ........