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Saturday, November 30, 2013

No start on DT466 EGR and Maxxforce DT

Hello, all. Here is more information on DT466 EGR and Maxxforce DT engines that won't start. This information was presented by a reader as a comment to my post on Maxxforce DT no start. It contains so much good information and is so well written that I decided to take it out of the comments and use it as a post.
It was written by a reader who calls himself CKing10304. If the writer wants to have his name put on this post as the author, he or she should send me an email. Thanks.

Regarding the fuel system components: you were unclear whether this was a Maxxforce DT or a DT466 EGR. The pictures indicate that it is a DT466 EGR. Fuel pressure regulators are available for either engine. The difference between the two is that the DT466 EGR engine does not have a fuel return to the tank, The Maxxforce DT does have a return to the tank. The older, non-EGR DT had a fuel pressure regulator on the fuel rail at the back of the head, which went back to the tank. If we are talking about an EGR DT, it is critical to inspect the fuel filter housing for debris. The check valve in the fuel pump will sometimes come apart and end up in the fuel filter housing. You will notice the spring metal and pieces of the white plastic poppet lying in the bottom of the housing during a fuel filter change. It is a good bet that the fuel pump will need to replaced in this situation (there was a recall on these engines for this situation). As far as "No-start when hot" situations, this usually indicates an ICP leak under the valve cover, mostly high pressure oil rail O-rings. This is not a "silver bullet" for diagnosis however. One must start at one end of the system and work their way up to the HP rail. Base engine oil pressure is first. If the engine is slow to build base EOP, then the high pressure pump doesn't have a chance to do it's job. It doesn't take much-if you have 3-5PSI of bas oil pressure during cranking, that is enough to supply the high pressure oil pump. A quick check to verify this is to remove the oil temp sensor in the front cover. That area of the front cover is a reservoir that the high pressure pump uses to draw from. If oil does not spill out upon removing the sensor, you need to troubleshoot base oil pressure. Assuming you have an oil supply to the high pressure pump, you need to "full field" the IPR valve (regulator on the pump). If you apply 12v directly to the IPR (taking the ECM control out of the equation) and crank the engine, and still get low ICP on the laptop, then we need to verify the high pressure pump and regulator's ability to produce pressure. Removing the hose from the cylinder head, or using a test hose directly off the pump, with a 0-10,000 PSI gauge, apply 12v to the IPR and crank the engine. An EGR DT pump should produce 5000+ PSI. A Maxxforce DT should make 6000+. If this checks out then you have a leak under the valve cover. If the results are under those numbers, then you have a problem with either the pump or the IPR. There is a tool to thread into the pump that will bypass the IPR and cause the pump to produce maximum pressure. You can purchase the tool from an International dealer. If you install the tool and gain pressure, then the IPR is at fault. Replace it and re-test. Otherwise, if you full field the
IPR and get good pressure on the gauge, then remove the valve cover, unplug all 6 injectors, full field the IPR again, and crank the engine. Sending 5000-6000PSI up to the rail will indicate a leak. Repair accordingly and retest. There are 3 causes of under-valve cover leaks: high pressure rail O-rings, oil inlet adapters (pucks), or the injectors themselves. I recommend removing the rail once a leak is identified, if the orings are intact, replace the pucks and retest. If there are still leaks, then replace the injector(s). If the rail orings are failed, then reseal the rail and retest. Just my 2 cents.

November 29, 2013 at 3:34 PM

An additional note: click on the DT466E No Start tab above the posts to go to the sales point for my book on No Start Diagnostics.
Bruce Christopherson

2 comments:

Unknown said...

hi how to reseal the orings if is a leak on the pucks,i change the pucks with the orings nad still leak on the top of the injectors.

Unknown said...

Great information we're having IPR problems and a no start condition. Thanks for sharing the knowledge!