I read through the majority of this thread and didn't see the issue that I am having.

First, I don't own one of these YET. I would like to. I am looking at a 94 super duty that is a retired and very tired fleet maintenance tire truck. It has a PS engine I believe based on what I have read here.

The truck starts well first thing in the morning I drove it a couple of miles and everything looked good. Parked it back at the shop and shut it down. Tried to restart it and it would not. It cranks but doesn't seem to even try to fire.

I know that it has not been "well" maintained because there was only a hint of oil on the dip stick when I looked at it yesterday.

When I drove it this morning, after them charging the batteries last night, the engine seemed solid. Not a lot of smoke, basically I couldn't tell that it was smoking at all via the mirrors. Sitting still it was clean as well. I felt that it was running well.

They mentioned that they have had the issue of it not wanting to start again once it started in the morning. Their work around was to keep it running all day.

Only 185k on the engine. I am just wanting to play with the diesel. However, I want one that I can start(I don't need a pet). I have an opportunity to get this one for not much.

Why might the truck not want to start again when it has started cold easily but won't start warm immediately after being run?

 

make sure the oil is full, these things get picky when they are run low on oil, as far as not starting when warm it sounds like the IPR o-rings are struggling, you can buy a rebuild kit at international for like $18, no big deal, the IPR is on the driver's side of the hpop, on the back side. remove, rebuild, re-install!!!
basicly, the oil is thick enough when cold to creat enough pressure to actuate the injectors, but as the oil temperature increases, the viscosity decreases, making it harder for the worn out IPR o-rings to build enough pressure to properly fire the injectors

 

Forgive me. Some of the acronymns I can pick up on via the topic but the ones that you are using I don't understand. I was a diesel mechanic on subs in the early 70's but haven't worked on anything since then.

IPR = injector pump regulator?
Hpop = high pressure oil pump?

I am assuming that this is fuel oil/diesel that you are talking about here.

What might these items look like and where in the compartment would I find them?

Suggestions for manuals should I purchase this? Or online location for trouble shooting issues?

As I said in my original post this truck appears to have been abused. Are these engines able to handle poor maintenance well or will I be sorry should I get the truck?

Thanks for your earlier response. I will try to take another look at the truck on Monday.

 

He's talking about the engine oil. You mentioned, "...only a hint of oil on the dip stick when I looked..."

This could be the reason the engine is not starting. These engines need oil pressure to fire the fuel injectors. If the oil level is too low, there won't be enough pressure to fuel the engine.

You could be sneaky and haggle even more over the asking price in the hopes that the low oil level is the problem. I haven't replaced the IPR o-rings so I can't address that.

You're correct on the HPOP definition and close enough for government work on the IPR definition. (I'm not sure half the time myself.)

Is this an earlier 94 model or is it considered a 94.5 model? Personally, I don't the difference, but I think it's where the IDI (94 and earlier) engine leaves and the DIT (94.5 and later) engine comes in.

 

"He's talking about the engine oil. You mentioned, "...only a hint of oil on the dip stick when I looked...""

When I went to look at it today the oil had a "proper" level and it did start cold. I didn't check the oil level when I parked it to see if it had changed significantly. Probably should have.

"This could be the reason the engine is not starting. These engines need oil pressure to fire the fuel injectors. If the oil level is too low, there won't be enough pressure to fuel the engine."

That would be the issue with the "O" rings then. Okay. I can see that.

"Is this an earlier 94 model or is it considered a 94.5 model? Personally, I don't the difference, but I think it's where the IDI (94 and earlier) engine leaves and the DIT (94.5 and later) engine comes in."

Based on the articles on the board here, this is a 94.5 which is a PSD engine. Has the injectors and glow plugs under the valve covers and the factory turbo.

 

It could be the ipr (injector pressure regulator) which controls the amount (or the pressure) of oil the hpop supplies to the injectors.
The ipr is simply an electromagnet core around some very tiny pins that slide open or closed to allow oil to go to the injectors or back to be circulated.
As we all know from 5th grade science class, heat kills magnets. As the ipr begins to fail it will not fully engage the pin and cause a hot no start problem. As time goes on it will become a stall while driving/no start when hot problem. If your 7.3 is sitting in a van front end, as mine is, you can not even see the ipr until you pull the turbo, fuel pump and filter housing completely out.
The test for this is if when you have a hot no start, put some ice cubes on the ipr (blindly in my case) and give it a minute or two to cool the magnet and see if it starts. If so then you know what you need to do.
I am currently in the middle of replacing my ipr on my 97 ambulance, so this is all new information to me as well.
Good luck with your 7.3 if you buy it.

 

hot starts fail from

IPR oring
IPR weak
IPR tinnerman nut loose
HPOP leaking by
ICP sensor failing, un plug it and see if it starts
injector orings or internal injector oring fail, pop VC and check for leaking at base and check fuel filter for darkness

 

This thread is from 2009.