MEP 002A STARTING ISSUE

Cube

New member
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Before you do anything else to the pump, make sure your batteries are in good shape, it sounds like they may be wearing down as you are cranking.
Next, are you using the glow plugs? If so how long?
You might need them for 30 seconds min.
If that doesn't help we may need to verify the glow plugs are working.
Also, make sure that while cranking the IP throttle linkage is lifting fully upward and not binding up on the sheet metal or anything. Have someone push up on the linkage with a finger while you are cranking to verify it is fully upward.
Ray,
Both batteries are new 27 series larger than needed .
Powered glow plugs for 1 minute
Then prime/start.
After several attempts now no smoke.
IP throttle linkage moves up about an inch when I energize starter.
I'll have to check glow plugs but still may be a fuel issue.
I worked carefully and straightened spring like it was before I got bent.
 

Cube

New member
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Location
33619
Ray,
Both batteries are new 27 series larger than needed .
Powered glow plugs for 1 minute
Then prime/start.
After several attempts now no smoke.
IP throttle linkage moves up about an inch when I energize starter.
I'll have to check glow plugs but still may be a fuel issue.
I worked carefully and straightened spring like it was before I got bent.
By the way check this website for pump rebuilds. They list the Bosch pumps.
 

Chainbreaker

Well-known member
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If there is anyway you can post a video of your starting attempts it might help with member troubleshooting advice. Would be good if an assistant could capture a video of exhaust while attempting to start and of course the sound of it while turning over.

One thought I had was regarding compression since you said it turns over fast then slows down and you said it had new batteries. Wondering if compression starts low and then builds up a bit while trying to start it? A video with good sound would help understand more of what is going on.

However, it does sound more like a fueling issue as I reread the thread sequence of symptoms you describe.
 
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Ray70

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Unfortunately the PSU pump shown on that web site ( for $780 ) appears to be an exchange not really a rebuild.
I think you send them the PSU and you'll get an Ambac M50 for $780!
It's cheaper to just buy yourself an M50 outright, when they are available.
The #1 failure point of the PSU is a broken plunger shaft, which ( I checked everywhere, even spoke to ambac service directly ) no one supports the plunger because it is a mated part with the pump body.
In your case the plunger appears to still be ok since it is still turning and plunging in and out.
 

dangier

Member
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Page County, VA
Unfortunately the PSU pump shown on that web site ( for $780 ) appears to be an exchange not really a rebuild.
I think you send them the PSU and you'll get an Ambac M50 for $780!
It's cheaper to just buy yourself an M50 outright, when they are available.
The #1 failure point of the PSU is a broken plunger shaft, which ( I checked everywhere, even spoke to ambac service directly ) no one supports the plunger because it is a mated part with the pump body.
In your case the plunger appears to still be ok since it is still turning and plunging in and out.
Cube,
How tight are you getting the delivery valve holder? I have had to tighten the holder beyond spec on a few units to get the ip to make enough pressure to start. Also have never had to use grease to hold parts on re-assembly. They have just gone in the right place.
David
 

Guyfang

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Ray,
Both batteries are new 27 series larger than needed .
Powered glow plugs for 1 minute
Then prime/start.
After several attempts now no smoke.
IP throttle linkage moves up about an inch when I energize starter.
I'll have to check glow plugs but still may be a fuel issue.
I worked carefully and straightened spring like it was before I got bent.

Have you tried to disconnect the linkage from the solenoid and operate it by hand? It maybe your linkage is stiff, or not oiled and move freely, or simply needs adjustment. Get someone else to crank it over, and you move the linkage up to full fuel.
Open to read comment.
 

Cube

New member
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Location
33619
Open to read comment.
Yes, I have 7' of reach and can hold fuel lever up and crank at the same time.
Tried that with no change in smoke or start. Lever and solenoid move freely to full up position when cranking.
But a reoccuring problem, the starter quit working. I'll have to renove it and rebuild it possible put a new solenoid on it.
Getting frustrated!
 

Cube

New member
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3
3
Location
33619
Cube,
How tight are you getting the delivery valve holder? I have had to tighten the holder beyond spec on a few units to get the ip to make enough pressure to start. Also have never had to use grease to hold parts on re-assembly. They have just gone in the right place.
David
Well I am not so lucky as the spacer will not hold the valve in place it just drops down. And the spring may stay in place in the cap but since it didn't last time I assembled it that is why it bent.
Valve dropped down and spring didnt catch the top where the needle pin has a locator.
Using the grease at least its pumping now possibly just not strong enough.
Now starter quit again.
 

Ray70

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Once you get the starter issue corrected, we can get back to it.
If the IP is pumping fuel but not enough pressure, the spring may be causing an issue, not keeping the delivery valve closed long enough.
Other than that the only other pressure issue I have ever seen with those pumps is pitting on the plunger not allowing it to build full pressure, but we're not at that point yet.
 

Cube

New member
17
3
3
Location
33619
Once you get the starter issue corrected, we can get back to it.
If the IP is pumping fuel but not enough pressure, the spring may be causing an issue, not keeping the delivery valve closed long enough.
Other than that the only other pressure issue I have ever seen with those pumps is pitting on the plunger not allowing it to build full pressure, but we're not at that point yet.
Ok, starter is working now, bad + clamp.
Still not enough pressure
Any sources for parts?

Bosch PSU pump.
 

Ray70

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You might be able to get some parts from Ambac ( parts that are common to the M50 ) if they will still sell to you, and I have spare delivery valve springs etc. if you need one, but if you have a pitted or damaged plunger you will need to source another pump.
I have also made some delivery valve spacers from teflon if you want one so you can avoid the grease scenario.
Send me a PM if you decide you want some parts to try fixing your pump.
 

Cube

New member
17
3
3
Location
33619
You might be able to get some parts from Ambac ( parts that are common to the M50 ) if they will still sell to you, and I have spare delivery valve springs etc. if you need one, but if you have a pitted or damaged plunger you will need to source another pump.
I have also made some delivery valve spacers from teflon if you want one so you can avoid the grease scenario.
Send me a PM if you decide you want some parts to try fixing your pump.
 

Cube

New member
17
3
3
Location
33619
Thanks Ray,
I would have to pull the pump apart to check for the plunger , it turns and moves in and out. I can put a new delivery valve spacer and spring and see if that cures the problem.
Let me know what I need to do to get in touch since, pardon me but, I don't know what PM stands for.
 

SCSG-G4

PSVB 3003
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PM is 'private message', which under the new software is called "Start Conversation". Move your cursor over their name or their avitar and a box will open that has the option of starting a conversation (among others).
 
Last edited:

Cube

New member
17
3
3
Location
33619
Before you do anything else to the pump, make sure your batteries are in good shape, it sounds like they may be wearing down as you are cranking.
Next, are you using the glow plugs? If so how long?
You might need them for 30 seconds min.
If that doesn't help we may need to verify the glow plugs are working.
Also, make sure that while cranking the IP throttle linkage is lifting fully upward and not binding up on the sheet metal or anything. Have someone push up on the linkage with a finger while you are cranking to verify it is fully upward.
Ray,
Sent you a PM but no response.
Let me know what else we can do to communicate.
Or maybe I just dont kbow how to do a PM.
 
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