M4500DT Injection Pump replacement

[Deep Tillage]

I'm sure this topic of replacing the injection pump has already been discussed but I could not find a thread that answered all of my questions. My M4500DT is hard to start when sitting for a few days. It blows a lot of white smoke until I can get it started. I found out that 1 glow plug has a resistance about 3x higher than average but I don't suspect 1 glow plug is the culprit (even though I'll replace it anyway) Once it starts, it runs and revs normal and will restart fine.

Here are my questions:

1. To replace the injection pump with a rebuilt one, is it as simple as getting the injector lines out of the way and removing the top bolts on the pump only and then sliding the "cartridge" out? No need to worry about timing even when replacing with a different rebuilt pump?
2. Under the pump, what is this valve? I assume it's for draining moisture? Can I open it and drain some fuel/moisture out without worrying about re-bleeding the lines?
   1. 
3. Any secrets or tricks to replacing the lifter fuel pump shown in the upper picture? I bought a replacement there also just to cover my basis.
4. Regarding the air cock bleed valve, the manual says to open it for bleeding purposes. Maybe this is a dumb question, but which way is open? Logically to me, it seems open is rotating the valve full CCW and closed is full CW. However, it appears to be opposite. Fuel does go to my injectors when that valve is full CCW.

Many thanks.

 

[North Idaho Wolfman]

Your problem is not the injection pump, it's the injectors and glow plug.

That valve you're pointing to does not go to the injection pump it goes to the block, it's for draining coolant out of the block.

Why do you want to change the lift pump?
It's not an issue either if it runs without stalling.

You will get fuel to the injectors either with the air bleed valve open or closed, if you leave it open you will starve fuel to the pump when it's under high RPM's.

 

[Deep Tillage]

Your problem is not the injection pump, it's the injectors and glow plug.

That valve you're pointing to does not go to the injection pump it goes to the block, it's for draining coolant out of the block.

Why do you want to change the lift pump?
It's not an issue either if it runs without stalling.

You will get fuel to the injectors either with the air bleed valve open or closed, if you leave it open you will starve fuel to the pump when it's under high RPM's.

Thanks for the information.

On the air bleed valve, which way is open? Counter clockwise or clockwise? Screwed all the way in or out?

Also, any idea what the normal resistance should be on one of these glow plugs?

 

[North Idaho Wolfman]

Counter clockwise is open, clockwise to close.

The glow plugs should be in the range of 1 to 2.5 ohms.

 

[JohnDB]

Deep Tillage, do you have any manuals for your tractor?

 

[Deep Tillage]

Counter clockwise is open, clockwise to close.

The glow plugs should be in the range of 1 to 2.5 ohms.

Thanks for the information. On the air cock vent valve on the side of the injection pump, mine has a slow drip leak- looks like it's coming from valve to pump interface. Can I unthread this from the pump and I assume there are some copper washer seals in there?

 

[Deep Tillage]

Deep Tillage, do you have any manuals for your tractor?

Yes, I have the WSM.

 

[lugbolt]

if you are seeing white smoke while cranking you're getting fuel.

As NIH said, poss injector problem. Also possible glow system problem(s) OR low compression pressure. What's your compression pressure as measured?

 

[Deep Tillage]

if you are seeing white smoke while cranking you're getting fuel.

As NIH said, poss injector problem. Also possible glow system problem(s) OR low compression pressure. What's your compression pressure as measured?

Thanks for the feedback. I checked the resistance on all 6 glow plugs. Only 1 was high (about 6-7 Ohms). I replaced that one and still didn't help the starting issue. Then I ended up replacing 4 more (I'll have to get to the one above the injection pump later when I remove the holder and line). After replacing 5 of the 6, it starts much better now. Lesson learned is don't trust the resistance measurements of the glow plugs as all is fine. In total, 2 of the glow plugs had large bulges on heating elements.