3126 Cat Engine - Diesel Forum

tleisner · 09-23-2008, 11:55 AM

Got a 2000 Freightliner FL80 with a 3126 cat motor. Complaint of a hard start problem. Replaced fuel filter and added injector cleaner to system. Found oil in fuel filter when I went to replace it. What would cause oil to get into the fuel system and how? Any remedies for this? Any help would be much appreciated.

Dave Haven · 09-23-2008, 08:02 PM

First off, Welcome to TheDieselStop.com!
The injector o-rings are leaking high pressure oil into the fuel rail.
Replace the injector o-rings. That will keep oil out of the fuel, and should cure the hard start problem.

tleisner · 09-24-2008, 09:47 AM

Thanks for the response Dave. Will be looking to this site for more info.

cenrep · 11-24-2008, 11:04 AM

hope this is the right way, any how here it goes. Engine is in a Sterling truck. Codes 164-11 injection control pressure problem and 164-00 erratic injection control pressure. Have replaced injectors, huei pump, and pressure sensor. During test performed, with gauge installed in oil rail and laptop connected at idle, gauge will read 2000 to 3000 pressure, but laptop display will read 1450 and diag will also display. Engine runs but has no power. Have checked wiring harness for damage but not harness to ecm. Any thoughts would be helpful.

Dualie · 11-24-2008, 11:56 PM

Oil in the fuel is injector O-rings with out question. The codes you have back that up.

Pull all 6 injectors and replace the injector O rings. Check the injector cups for coolant seepage buy pressurizing the system and visually inspecting for coolant leaking around the press fit injector cups.

grounder · 11-25-2008, 02:28 AM

Quote:

Originally Posted by cenrep

hope this is the right way, any how here it goes. Engine is in a Sterling truck. Codes 164-11 injection control pressure problem and 164-00 erratic injection control pressure. Have replaced injectors, huei pump, and pressure sensor. During test performed, with gauge installed in oil rail and laptop connected at idle, gauge will read 2000 to 3000 pressure, but laptop display will read 1450 and diag will also display. Engine runs but has no power. Have checked wiring harness for damage but not harness to ecm. Any thoughts would be helpful.

I am assumeing you have just replaced all the components you have listed in the above quote trying to fix this problem? What year is the engine.Does it have The External mounted Injection pressure regulator On the Pump?What kind of software are you useing is it CAT ET ? If so you should be able to go to special tests in the drop down diagnostic menu.Run the Inj pressure Step up test and Monitor actual pressure VS demand.If you are getting 3000 psi out of a Rail port at Idle with a external gauge The IPR is wide open.It seems The ICP sensor is telling the ECM it is only seeing the 1450 psi you describe,With the engine off,Turn the Ign. key back on.Then pull the plug off the ICP sensor,Give the laptop a few seconds and it should throw a High voltage code or Open for the sensor.If not check the voltage with a voltmeter at the plug should be 5 volts.This is just a quick way to see if the ECM is responding to the circuit.If you want to pm me with more info we may be able pin this down but, I need to know a few more specifics on what else you have checked if possible.

87LT500R · 02-28-2012, 05:41 PM

dualie is right replace injector o rings change motor oil clear codes and fire it up