Ok, so I have a 2001 F-350 Super Duty with the 7.3 turbo diesel. Its been well maintained and has 340,000 miles on it. About 4 months ago it went into a dealer for service and the dealer replaced the starter (slow cranking) and 3 of the injectors. (the old injectors have around 120,000 miles on them) Also fuel filter and some other minor stuff, but I don't think that had anything to do with the problem its having. It didn't go in for this problem and the problem was there a little bit for a long time and has only gotten bad lately.
When the truck has been sitting for 5 or more hours, it is very hard to start. It will first start and run for a few seconds, then die. Then it will take 30 seconds or so of cranking to get it to start. After starting it runs normally. If it is shut off immediately after it has [fully] started it also restarts and runs fine. There is no excess smoke or odd stuff happening. It starts fine if it hasn't been sitting for more than 4 or 5 hours. I don't think its a temperature issue, but I haven't tried plugging it in overnight. Recently it was used to do a long run pulling a 16,000 lb trailer. (we pull these trailers with it a lot) I showed the [hired] driver the cold start issue and he was ready for it the next morning. But the truck started and ran fine for the next couple of weeks, sometimes sitting a long time, sometimes not. The trip back was 1400 miles and on the morning of the last day, the problem started again.
This sounds to me like the fuel is draining out of the fuel system and it is taking a while to pump the lines back full again. But I'm no expert on these diesels. (I grew up with the muscle cars - give me a '68 goat and I can wring the crap out of her!) Could it be something like a check valve allowing the fuel to drain out? If the fuel were draining into the cylinders, I'd expect a lot of smoke on startup or something. There's none of that. No fuel leaks or fuel smell either. Once it has gotten started, it runs fine all day long. No problems unless it has been sitting for several hours.
Any ideas anyone?

 

Is there excessive blow by coming out the oil fill tube? With the engine running, turn the cap upside down and place it on the tube and see if it stays there. It might vibrate around a bit but shouldn't get blown off.

Are you getting smoke out the exhaust when it doesn't want to start?

 

Well, this morning it decided to start fine. OK, it cranked a little long, but it was a bit cold out and I forgot to plug it in last night, so it was a totally normal start. Guess I'll try again tomorrow.
No there's no excessive blow-by. And no the oil cap doesn't even vibrate off, this thing purrs beautifully at idle!

 

Moved to the 1999 - 2003 7.3L Powerstroke Diesel forum.

 

Original LPOP? Classic signs of worn LPOP, but could also be the IPR valve.

 

Well, to my knowledge, it has the original LPOP, HPOP, IPR valve... The injectors have been replaced 125,000 miles ago (3 of them about 4000 miles ago) but most of the rest of it is original - 340,000 miles. I will have a shop do the work on it, when it is worked on, but I'm suddenly thinking it might be a valid arguement to have them replace the HPOP, LPOP, IPR valve and fuel pump, if for no other reason than it is so much work to tear down for any one of the things, vs the cost of just replacing all the things while it is apart. Hmmm.

 

How is the Glowplug relay ? 340.000 miles is a lot if its still the stock GPR. Next time it acts up, wait until the motor is cold. getting help will make this easier. open the hood. have them turn the key on but don't try to start it, then you need to jump the two big terminals across as soon as they turn the key on and you must jump it across for about 5 seconds , remove the jumper and have them start the truck and see if its starts normal. this is a quick check to see if's its going bad. a bad relay will not act up all the time and is more likely to act up on first starts.

 

Have you checked the HPOP reservoir to see if it is full after sitting for a while? Sounds like it may be leaking past the check valve and has just enough oil to run for the few seconds you mentioned and then need to crank it enough to fill the reservoir again. Just a thought.

 

OK, Hydro Man, now that sounds exactly like what's happening. I don't really know much about the intracacies of these engines. Is there a way to check the HPOP reservoir? And if so, how? I have no idea where the thing is, but it just feels like the lines (or in this case oil reservoir) are bleeding down and after filling back up (under pressure) it runs fine.

 

My 2000 F450 with 240K had same issues. It does when it sat for long time.

Like 2-4 days when you crank it wasn't glow plug relay it related to oil since oil gauge red light stay on after crank for like 30 seconds before it come alive. But red light stay on for like 15 sec after running.

Oil were nasty black so I hope it not HPOP or checkball clogged by sludge.

 

The flip side of the equation here is the HPOP is going through the oil stored in the reservoir from the last run quickly, and the LPOP isn't replacing it fast enough because it is worn out after 340k. Anti Drain-back valves are a very rare problem. It consists of a threaded plug, spring and steel ball. Not much to go wrong there unless clogged to the open position like mentioned above. A bad IPR gives a similar symptom to the ones listed in this thread. If you find the HPOP reservoir full prior to starting, I would suspect the LPOP at your mileage.

 

How good are your batteries? Is it turning over with gusto or is it still draggy?

 

battont - The HPOP reservoir is right at the front of the engine on top. Under the plastic PSD cover if you still have it. There is a plug on top, allen head IIRC. Oil level should be within about a half inch or so. Check with engine OFF, big oil bath otherwise.

 

I'm new to diesel engines as well, do you have to do an oil change on either the HOPO or LOPO? If you do, how? Anything else special we need to know about these engines?

Crazyotto

 

I nearly spewed my coffee across the room. And i'm not laughing at you otto, definatley with you. Once you've been here a while you'll understand what I mean.

"NEED" to know, probably not, but there is tons you'll want to know, They are addictive and there is so much to do with respect to preventative maintenance and performance upgrades.

The HPOP has a reservoir that has a plug on top through which you could drain it by suctioning out the oil. Most feel it's not necessary. The LPOP has no reservoir. It takes engine oil and feeds it to the HPOP reservoir. The HPOP pushes that oil through the injectors and then it exits the injectors into the heads. It drains down through the engine to go through the cycle again.

battont,
Here's a component piture thanks to tdpower.
Ford Truck Enthusiasts Forums - tdpower's Album: Useful pics - Picture
The HPOP and HPOP plug are at the bottom of the picture/ front of the eng. It is an allen head plug and easy to access. If you open it after the trucks been sitting a while and it's not close to the top, 1/2 inch or so, then it's bleeding down. More likely as mentioned above would be the LPOP worn and not feeding it quickly enough to keep up. watch your oil press dummy gauge and light on dash at crank and see if it takes a bit to come up. Good news is a LPOP change is not too difficult and not terribly expensive.