Mep 003 injection issue

[GASCANS001]

I have made a post prior to this on fixing up my 003 for my step dad

I’m continuing to fight this issue.

This set has 236 hours not on rebuild. It’s a 92 model I believe. The issue at hand is it’s a dog to start. Spray a good sniff and it’ll take off but with out it, it will not. Once it pops off it’ll run for maybe 30 seconds and it stalls out. (Appears once it gets a little heat inside of it it shuts off and will not restart ) I’m getting a ton of white grey blue smoke. I replaced the head gasket as it was blown, Sent the injectors off to Area Diesel Service to get rebuilt, and completely rebuilt the fuel system (new lines, new pump, spin on filter adapters with Wix 33528, Wix 33405) and after the head gasket and injectors it’s worse.

Before I send this injection pump off does anyone have any other checks they recommend?
It’s worth noting I did set the valves according to the tm. Also the injector nozzles were so bad ADS made new ones. I know the tank is extremely dirty sp I by passed it from day one.
Im getting drips from the return line I would think it would be more of a stream which is why I Feel like it’s an IP issue.

What are your thoughts?

 

[Guyfang]

Did you check/test/ replace the preheaters?

 

[Ray70]

ADS made new nozzles for your injectors?? How much did that cost? Wonder why they didn't just buy new ones...
Your description is sounding to me like you pump's plunger guide has skipped and the pump timing is now way off.
Have you pulled the big cap off the center of the pump and removed the delivery valve and holder so you can see the tip of the plunger?
when you rotate the motor by hand the plunger should be rotating at 1/2 engine rotational speed and it should be plunging in and out 4 times per revolution.
If this is all happening correctly, the plunger guide may have skipped and messed up the timing.
if this is not happening then your pump is at minimum gummed up and stuck.

 

[GASCANS001]

ADS made new nozzles for your injectors?? How much did that cost? Wonder why they didn't just buy new ones...
Your description is sounding to me like you pump's plunger guide has skipped and the pump timing is now way off.
Have you pulled the big cap off the center of the pump and removed the delivery valve and holder so you can see the tip of the plunger?
when you rotate the motor by hand the plunger should be rotating at 1/2 engine rotational speed and it should be plunging in and out 4 times per revolution.
If this is all happening correctly, the plunger guide may have skipped and messed up the timing.
if this is not happening then your pump is at minimum gummed up and stuck.

So to have all four rebuilt with new seals and all the internals cost me $250 total. The nozzles were $30 each of that $250. To have my pump rebuilt will be around $400

So you’re thinking it’s either stuck and dirty or the plunger sleeve is broken or out of time.

I will say I took the inspection cap off the pump and pulled the silvery valve out and when I rotated the engine with a bar the plunger was moving and wasn’t stuck. When I turn the pump on and sent fuel to it, it was dumping out of inspection port so I know the pump is getting plenty of fuel.

I appreciate your response!

 

[GASCANS001]

Did you check/test/ replace the preheaters?

I have not as I can’t find them.
I did bypass the fan shroud at the temp sensor and ruled that out. It’s definitely mechanical fuel issue.

 

[Ray70]

So your pre-heaters are mounted in the intake manifold, look like 2 spark plugs screwed into the top of manifold.
Running the heaters for 20-30 seconds should make the intake feel warm to the touch.
The glow plugs are screwed into the side of the heads under the intake manifold coming straight out the side of the head.
When the injectors are out, the tips of the glow plugs stick right into the side of the chamber where the injectors sit.
You can pull the wires off and test with an ohm meter, or they should feel a little warm after 30 seconds of on time.

I'm thinking the plunger guide in the pump may have skipped, causing timing to be like 90* off.
Assuming this is an Ambac M-50 pump and not a PSU pump.
I've seen it dozens of times and there are plenty of posts on here with the same issue.
Including this towards the end.

MEP- 002a losing 24v power at start-up?? POWER ISSUE SOLVED!

Ray do you see any other parts I may need for the pump install.

www.steelsoldiers.com

 

[GASCANS001]

So your pre-heaters are mounted in the intake manifold, look like 2 spark plugs screwed into the top of manifold.
Running the heaters for 20-30 seconds should make the intake feel warm to the touch.
The glow plugs are screwed into the side of the heads under the intake manifold coming straight out the side of the head.
When the injectors are out, the tips of the glow plugs stick right into the side of the chamber where the injectors sit.
You can pull the wires off and test with an ohm meter, or they should feel a little warm after 30 seconds of on time.

I'm thinking the plunger guide in the pump may have skipped, causing timing to be like 90* off.
Assuming this is an Ambac M-50 pump and not a PSU pump.
I've seen it dozens of times and there are plenty of posts on here with the same issue.
Including this towards the end.

MEP- 002a losing 24v power at start-up?? POWER ISSUE SOLVED!

Ray do you see any other parts I may need for the pump install.

www.steelsoldiers.com

I’m thinking it’s out of time too. Because if it was sticking the plunger wouldn’t as buttery smooth as it is.

I’m searching the heck out of the TM’s I can not for the life of me find the injection pump timing section. I’ve read it before but now I can’t find it.

Thank you for the schematic of the plunger assembly.

To put back in time I assume you’re referring to the pump itself right?

Edit: forgot to mention yes it’s the m50 pump

Intake heaters work but the glow plugs are needing some attrition bee searching and all I find is the ones for 125 each

 

[2Pbfeet]

FWIW: I don't know if this is the correct one, but there are a couple of listings on ebay at the moment under both the NSN, and the Wellman-Thermal part number;
$58 https://www.ebay.com/itm/152159143310
$49 https://www.ebay.com/itm/256380544726

I'm a little superstitious about glow plugs and tend to replace them in sets.

All the best,

2Pbfeet

 

[Ray70]

Well, there are 3 things at play regarding pump timing.
1) The gear that rotates the pump internals meshes with a gear on the camshaft.
That "Timing" is set by putting the "PC" mark stamped on the flywheel aligned with the pointer on the bellhousing with the engine on cyl. 1 compression stroke. Once installed correctly this can not change unless someone removed the pump and reinstalled incorrectly.
You can verify this by removing the small screw on the left side of the pump's mounting flange and inserting a 1/8" drill bit ( butt end ) and with the motor set on the PC mark the drill should align with a slot cut in the side of the IP's drive gear.

2) The gear drives the plunger guide which acts as a "shear pin" to drive that center plunger. It is designed to split in half if the pump gets stuck, but often times I find them just damaged to the point where the plunger skips 90* or 180* within the plunger guide. This is what I think may have happened to you, if the machine ever sat for a long period of time and the fuel got gummed up in the pump. This requires pump disassembly to verify.

3) The timing button under the cap that rides against the cam lobe, creating the pumping action is the fine adjustment of exactly when the IP delivers it's fuel shot. This is unique to each pump / engine combo and would not change unless someone changed the IP on the engine. This can be verified using the "flowing the pump" timing method described in the TM on page 145, the IP sections begins on page 136 of the -34 TM.

NOTE: be careful referencing the TM with regards to the IP components because the pictures all show the American Bosch PSU pump, not your Ambac M-50 so the pictures don't show the plunger guide that you have.
If you need the Ambac files I have them, but I think they are also available in the 002/003 TM files.

 

[GASCANS001]

Well, there are 3 things at play regarding pump timing.
1) The gear that rotates the pump internals meshes with a gear on the camshaft.
That "Timing" is set by putting the "PC" mark stamped on the flywheel aligned with the pointer on the bellhousing with the engine on cyl. 1 compression stroke. Once installed correctly this can not change unless someone removed the pump and reinstalled incorrectly.
You can verify this by removing the small screw on the left side of the pump's mounting flange and inserting a 1/8" drill bit ( butt end ) and with the motor set on the PC mark the drill should align with a slot cut in the side of the IP's drive gear.

2) The gear drives the plunger guide which acts as a "shear pin" to drive that center plunger. It is designed to split in half if the pump gets stuck, but often times I find them just damaged to the point where the plunger skips 90* or 180* within the plunger guide. This is what I think may have happened to you, if the machine ever sat for a long period of time and the fuel got gummed up in the pump. This requires pump disassembly to verify.

3) The timing button under the cap that rides against the cam lobe, creating the pumping action is the fine adjustment of exactly when the IP delivers it's fuel shot. This is unique to each pump / engine combo and would not change unless someone changed the IP on the engine. This can be verified using the "flowing the pump" timing method described in the TM on page 145, the IP sections begins on page 136 of the -34 TM.

NOTE: be careful referencing the TM with regards to the IP components because the pictures all show the American Bosch PSU pump, not your Ambac M-50 so the pictures don't show the plunger guide that you have.
If you need the Ambac files I have them, but I think they are also available in the 002/003 TM files.

Thank you for such a detailed response! I’ll verify the timing and report back. This may be a few days before I am able to do so. Once I have I’ll report what I find! Thanks again