International 4900 DT466E No Start

[DeepList]

Anybody work on diesel engines? I'm having a hell of a time with my International, and I'm running out of ideas...

It's a 1996 International 4900 with the DT466E turbo. Eaton Fuller 6 speed. I changed the fuel filter and cleaned out the sediment screen a few days ago. I used the schrader valve on the filter housing and the primer button to bleed the air out of the fuel system until I was getting straight fuel. Now the truck will not start. I disconnected the fuel return line at the back of the fuel rail assembly and I'm getting fuel coming out whenever I prime or try and turn the truck over. If I spray it with ether, it will run for a few seconds and then die, so there's obviously a fuel delivery problem here, but I can't figure out what the issue is. Since it fires with ether and runs for a couple seconds, it's led me to believe the injectors aren't firing... I just don't know what that would have to do with changing the fuel filter or cleaning out the catch screen. The injectors run by a high-pressure oil pump. I have oil pressure while it's trying to turn over. I've checked all of the wires. All of the fuses are good.

If anybody knows anything about Internationals, diesel engines, or more specifically the DT series and/or DT466E, I'm open to suggestions or ideas. This has been puzzling me for a couple days now.

The only code I'm getting from the diagnostic button is 111, which just means ECM OK.

 

[Firefighter181]

We had a similar issue in one of our rescue trucks at the fire station a few years back. Ended up being the o-ring in the quick connect where the line plugs into the filter housing. There is a little pressure check ball thing with a Phillips head next to the hand pump that had come loose also. May or may not be helpful.

 

[DeepList]

A diesel mechanic that I spoke with said that it may simply be crappy oil that's not building enough pressure via the HPOP (high pressure oil pump) to fire the injectors. Since I have no idea when the last time the oil was changed by the previous owner, and it was at the "add" line on the dipstick, I drained it yesterday in preparation to put in fresh oil... then I realized that I had the wrong oil filter, so now I'm at a stand-still until I have the opportunity to get the correct filter.

If putting in good oil doesn't do anything (which it probably won't) I'll look at the check ball as you suggested, but since I'm getting plenty of fuel from the return line, I'm leaning towards something wrong with the HEUI (Hydraulically actuated Electronically controlled Unit Injection) more specifically a sensor that's involved called the ICP (injection pressure control) or the IPR, injection pressure regulator valve... There's certain tests that can be done to rule them in/out of the equation.

I'm open to any other ideas and opinions. I'll will update this thread as soon as I find out anything. I'm sure google will bring other people here that are looking for similar answers.

 

[Firefighter181]

Any idea what the HPOP is making pressure wise? Not a diesel guy buy have helped the city guys work on the truck and recall idle pressure was 400-500ish and somewhere in the 1400-1500 range at WOT. No/low oil pressure would explain the no fire. The IPR can be full fielded to test I remember the shop tech trying that but he kinda laughed at the same time that "we really should not do this, but it works to test" LOL. Do you know what/if it is making any fuel pressure?

 

[RichV]

I bet you just have air in it. Had that happen to our 7.3L Excursion, not sure what you can do other than run the air out naturally.

Does it have a mechanical lift pump? Those can be a ***** to prime if you have air in it. Also, obvious, do you have fuel in the tank?

 

[DeepList]

Any idea what the HPOP is making pressure wise? Not a diesel guy buy have helped the city guys work on the truck and recall idle pressure was 400-500ish and somewhere in the 1400-1500 range at WOT. No/low oil pressure would explain the no fire.

I know the engine builds around 50 psi of oil pressure during crank, but I have no idea what the HPOP is at. I think it needs around 800-ish to fire and around 2000-3000 at throttle. However, since I don't know what the pressure is, I'd have to tee from somewhere to read it with a mechanical gauge. I did pull the oil temp sensor from the HPOP reservoir and verified that there's oil in there.

The IPR can be full fielded to test I remember the shop tech trying that but he kinda laughed at the same time that "we really should not do this, but it works to test" LOL.

The IPR is a little tricky to test because it has to be plugged in for the engine to run. It needs to be checked for power and ground. In order to do this, I'd need a buy a "breakout" harness from Navistar, or try to make my own using paperclips or something and try my best to not short it out. This allows for a voltage check at key-on and during cranking. If there's no voltage, you can apply 12v through the breakout or make-shift harness in order to rule out a wiring issue. If the engine starts, it will need to be killed immediately due to the oil pump being wide open.

The ICP is easier to test and can be done by simply unplugging it. Again, if the engine starts, then it has to be killed immediately due to the oil pump being wide open.

Do you know what/if it is making any fuel pressure?

Fuel pressure should be like 60 or 70 psi I think. But I don't know what that is either, and there's no way to tell unless I tee from one of the high pressure fuel lines and read it with a gauge, but then I'd be introducing more air into the fuel system by doing this.

I bet you just have air in it. Had that happen to our 7.3L Excursion, not sure what you can do other than run the air out naturally.

Very possible, and if that's the case, I'm chasing my tail here because I have no idea how to get the air out when the damn thing won't run for more than 2 seconds. I don't want to keep shooting it with ether because something will eventually go horribly wrong.

Does it have a mechanical lift pump? Those can be a ***** to prime if you have air in it.

There's a cam style fuel lift pump. It's located on the back half of the HPOP.

Also, obvious, do you have fuel in the tank?

It has dual tanks that self level. Both valves are open and each tank is about 50% full.

 

[DeepList]

I figured I'd reply back here with my findings for anybody who may stumble by through Google.


First instincts were a fuel supply issue, but fuel pressure was good. Cranking the truck and using the hand primer both resulted in adequate fuel being pumped through the high pressure fuel rail and back to the tanks via the return line. I checked all the fittings and the check ball. Everything was good. There was a new filter (full of fuel) and the rock strainer was clean.


The IPR and ICP both tested good.


Upon cranking, the tach would show intermittent signal, or no signal at all, so this led me to believe the CPS (cam position sensor) had failed. The CPS is a common part to fail, and often leave a truck on the side of the road with a no-start condition. So I ordered another. I popped it in, and the truck started right up. Why it failed immediately following the change of the fuel filter and cleaning the pre-filter??? Coincidence is the only explanation I can come up with.


Moral of the story:
Keep an extra CPS in your tool box. I'm actually going to order a spare and keep it with me in the truck in case this happens again. They're easy to change, even road side. All that's needed is a 10mm socket and perhaps a flat blade screw driver for prying leverage.