ok first let me introduce myself. I've been a member on here for about 6 years I think, hanging out in the IDI forum. I have a 1994 international 4600 Allison 454 dt444. the problem I'm having is this. three weeks ago, used the truck all day, ran fine but I have had a leak down issue. if the truck sits for a few days itll fire right up then die then crank a few times start and run great. parked it at the shop, 7 days later go to move it, it turns over veeery slow. pull the batteries. charge and test them one tested bad other weak so I replaced them both with two new G31 batteries from Napa. Fast forward to today. install the new batt's clean terminals put it all back together. it cranks over like it should but no start. check fuses and relays, no love. crack the supply line from the filter housing to the HPOP, had fuel there when cranking. so I did a bad thing, disabled the GP relay and gave it a shot of either, it shuttered a little and went to running. idle is smooth, no misfire that I can hear, ran the truck through the rpm's ran smooth. drove it around the shop a bit no issues. parked it shut it off and restarted it after approx. 1 minuet and no start, no smoke or fire, just cranks over


so what you guys think?

 

Sounds like a GP issue, but after even a minute of running, it should have fired right back up with no glow plugs.

Next time take a big screw driver or wrench, and jumper across the GP relay for 15 seconds and see if it starts better.

 

I don't think its a gp problem. I can hear the gp relay pull in and after the WTS light goes out I hear it drop out and the pitch of the sound the brake booster pump makes changes. so I know the GP's Are pulling a load on the batteries. I would also think id have a little white fuel smoke while it's rolling over and I don't have any. im guessing I have a high pressure oil issue or an electrical/sensor problem....im not used to wrenching on diesel's with all these damn wires lol

 

Not building enough HPO pressure at 200 rpm for the pcm to fire the injectors? Just a WAG.

 

where is a good place to check the hop pressure and what should it be?

 

pull the oil galley plug out of the back of one of the heads and install a 3000 psi gauge. not sure on your vehicle, but the powerstrokes needed to have 500 psi cranking before the pcm would fire the injectors.

 

IPR O rings?

 

Ok so I checked my hi oil pressure, when the truck was cranking it made almost no pressure, around 100 to 150 psi. after about 30 seconds of cranking the pressure slowly rose then when the engine fired it quickly spiked to around 2500 psi then fell back to 750-800 at a cold idle. engine idles smooth. as I increased rpm's the pressure slowly climbed to 1100 psi at 1700 rpm, then fell back down to 750 when I let off the throttle the needle wasn't bouncing or acting erratic when it was running. no misfires or rough idle. I shut it off and pulled the plug for the hpop oil reservoir it was full to the very top but engine oil pressure is slow to climb when cranking. guage in the cab says its about 35 psi at cold idle but I don't notice any lifters clattering or odd noise

 

Mine is 65psi at cold idle.

 

Check the hpop oil level before attempting to start tomorrow. If it's low the anti drain back valve is probably staying open

 

checked it today, it was low, couldn't tell how low, but it was not near the top. I'm kind of leaning toward either a worn lpop or a bad low pressure regulator at this point. my book says operating range on the low oil side is 35 to 70 psi. I'm down to the low end of that. I put my own gauge on the hpop reservoir to verify my pressure in the cab, right at about 40 pounds cold idle

 

Sounds like a drain back issue to me.

 

i assume there is a check valve in the hpop reservoir supply circuit someplace.....where might that place be? I pulled the passenger side valve cover off today because it was easy to get to. the head and injectors were extremely clean.... I mean spotless. got it started and observed the valve train and injectors. nothing odd there. there was some oil flowing from the injectors which I assume is normal, it did not appear to be excessive

 

The oil should flow out of the injector spouts each time it fires. Oil should not come out around the base of the injector where it get inserted into the head.

The anti-drain back valve is in the front cover, IIRC. Double check for sure though.

 

It's just behind the front cover on the driver side of the valley
drain back valve