I had a FE300 with the DT 466 and egr . Bus been sitting for months so I thought I would take it out for a spin . Well about 3 miles from the school I started losing power , then it bucked and stopped . Checked fuel presure . Had a 335 and a 341 codes . I tried to see what the ICP pressure was and cranking it was just over 800 PSI . I could clear the codes and then crank and after 30 seconds engine light comes on and the codes come back . I am thinking my HPOP is bad . Is there any way to bypass things to start it and get it into the shop ? We had it towed but the wrecker didn't place it near the shop . Thanks
I need to throw some new numbers here . I just hope somebody reads this . I looked at my service maxx again . When I am cranking I get 12 psi on ICP . The 800 0r 900 is desired . so either a bad ICP or HPOP . anyway still to get it running short of replacement of these items ?
First things first. When you are cranking the engine what is the engine oil pressure? Check the engine oil level and pressure first. No engine oil pressure means no oil for the HP system.
I have seen the ICP sensor go out just sitting in the yard overnight. I would replace the ICP sensor first since its pretty easy to do in about an hour and then try to start it. If that made no difference I would full field the ICP regulator and see what the reading are. (the regulator is a pulse width modulated system and the HP oil should pretty much max out if the regulator is working good. Do not run the engine in this manner other than to find out if it works or not). You can get a pigtail from your local IC truck dealer (RWC) and make a test harness for your tool box for about $30,00. Remove the regulator and inspect the Screen. If it has damage then replace the regulator and try to start it. (seen this a few times).
If this does not work then I would connect a mechanical gauge in the HP pump to cylinder head hose to get a true reading of the HP pressure. This would tell you if you have a bad HP oil pump or regulator.
Went out to bus on Friday and yes I do have oil pressure . The tach is moving . Before I went home Friday bus wouldn't turn over so I put the charger on it . This morning went out and tried to turn engine over just a click . Batteries are charged up . Then I noticed when I turned the key on no noise ? I should hear things on the engine being tested by the ECM ? Also the wait to start light won't go off . So I hooked up my laptop and it can't get any info from the ECM ? Bad ECM ? wiring ? Relay ? I checked the wiring in the battery box . Fuses and wires look good ?
Imo the bus running and then cutting out bucking loosing power... shooting off the hip I would suspect a faulty or sticking ipr valve first , or possibly the no crank no communication issue somewhere is related ? I would double check the ignition switch isn't failing ,*** check the connector for ignition switch*** I have seen many melted we keep connector and pig tails in stock for this reason for these . -other than that if nothing is found I know checking pins at the ecm Is a royal pain on these no room , so I would check the relays at the front and chase possible power loss from there .
Do you have access to Navistar Service? There is a hard start no start diagnostic form and a performance diagnostic form which gives you step by step procedures to diagnose the issue. Don’t panic! These engines are some of the easiest to diagnose and repair. Send me your email address to schoolbuspm@outlook.com along with the vin # and I will send you the diagnostic information.
No I don't have Navistar service . I went out and found loose wires at the starter . Got the engine to turn over . I have a gauge that goes up to 5000 psi .I installed that to the hose coming off the HPOP . Turned engine over for 30 or 40 seconds . Needle didn't move .Last time I ran that same test on another bus had the same result .Installed a HPOP on that bus and it started . So HPOP ????
Don't condemn the pump. The IPR valve located on the pump has to be powered before the pump will build PSI. Unplug it and check for power at the connector. Make note of which wire is showing battery voltage. Also insure you have oil in the HPOP reservoir by pulling the oil temp sender part way out. If oil is present, the reservoir is full. Please email me at schoolbuspm@outlook.com and I will send you all the diagnostic information. Put a reference to this topic in the subject line.
04 DT 466 won't run , can I bypass
Posted - 02/09/2018 : 10:38:00 AM
