Need Some Help

[Tizzy]

So, I have something that I can’t get figured out. My truck has been having difficulties starting lately. Once cranked. It runs fine. Turn it off immediately and then crank…starts quick. Turn it off let it sit for 30 minutes or so, won’t start. Let it sit a few hours. Starts after a few cranks.
I have replaced the glow plugs, and it is getting fuel. Any help on this would be appreciated.

 

[IDIBRONCO]

My first guess is that your injector pump is going out. It's called heat soaking. These sound like typical symptoms. The next time it happens, pour some cool water over the top of your injector pump. If the engine starts after that, then you know that it's time for a new pump. As ta pump wears, the internal tolerances get bigger. When the pump is hot from driving for a while, the tolerances open up even more. The cool water cools the pump back down and closes up the tolerances a little bit and it will pump enough fuel to get your engine running again. I've seen it said to not use cold water and that could be kind of bad. I don't remember why.

 

[Tizzy]

Thank you IDIBRONCO! I will give it a try.

 

[chicken bones]

I was having a similar problem once , turn out the starter motor was not cranking the engine quick enough. Maybe yours is cranking slower when hot ? New starter solved my issues .

 

[Cubey]

I've seen it said to not use cold water and that could be kind of bad. I don't remember why.

Thermal shock. An explanation from a site talking about not washing hot cooking pans in cold water:

The problem arises when you introduce a sudden change in temperature, like putting a hot pan in cold water. The metals cool too quickly and the pan actually starts to pull against itself. The bigger the temperature difference, the greater the shock, but even a small amount of cold water in the bottom of your sink can cause a pan to warp, shatter, crack or chip.

A scientific explanation: https://engineeringlibrary.org/reference/thermal-shock-and-stress-doe-handbook

 

[IDIBRONCO]

I was having a similar problem once , turn out the starter motor was not cranking the engine quick enough. Maybe yours is cranking slower when hot ? New starter solved my issues .

This is also a possibility. I tend to mention the water on the IP first since it doesn't cost much and is easy to do while keeping clean.

 

[Cant Write]

Is it worth mentioned that the CDR valve gasket is in good order as to not have water get into the crank case?

 

[IDIBRONCO]

Not a bad idea if you're talking about the lower one. I think that spot in the valley pan is slightly raised so you may be able to get by even if that seal isn't in the best shape and the drain is open. You'd want to poor the water slowly. If you flood the poor IP with water than that wouldn't help.

 

[Old Goat]

Make sure the valley Pan Drain is not clogged,
or the water will pool up.
The hole is only the size of a square end of a 3/8" extension.

Goat

 

[ihc1470]

The reason cold water on a hot pump is not a great idea is due to the close tolerances inside the pump. It is a good way to seize a pump and cause so very expensive repairs. More likely to happen if the pump is in good shape and not the root cause of the starting issue.

 

[Tizzy]

All, thank you for all the reply’s and help. I thought I would follow back up and let everyone know how things turned out. I tried the cool water test over the injection pump with no result. Which made me wonder if it was the pump giving me the problem. So, I ended up putting a Powermaster starter on, I figured what could it hurt, I wanted one anyways and the truck cranks faster than ever. Maybe starters are not immune to heat sink similar to injection pumps.

 

[Nero]

Starters absolutely aren't immune to heat soak, and all engines do need to meet a minimum rotation speed for starting. Could be it wasn't going fast enough.

 

[DaveBen]

As I recall IDI's need 500 rpm, from the starter, to fire.

 

[IDIBRONCO]

I tried the cool water test over the injection pump with no result. Which made me wonder if it was the pump giving me the problem. So, I ended up putting a Powermaster starter on, I figured what could it hurt, I wanted one anyways and the truck cranks faster than ever. Maybe starters are not immune to heat sink similar to injection pumps.

This is why I like to suggest the water test first. It doesn't cost very much. It's A LOT better than buying another IP just to still have the same problem.

 

[chicken bones]

You just dont realize have slow your starter is cranking until you put a new one in.