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Author Topic: Very little boost on my mTDI ALH Vanagon install  (Read 2144 times)

Reply #45November 10, 2018, 11:34:56 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #45 on: November 10, 2018, 11:34:56 pm »
You of course are absolutely correct, there's no point in introducing new variables into an unsolved running condition issue.  I'm just trying to find some kind of positive benefit from all this work.  So far I've not found any smoking guns inside the pump.   
'87 300TD (OM603)-->(OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'94 100CSQ Avant (AAH)

Reply #46November 11, 2018, 10:08:54 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #46 on: November 11, 2018, 10:08:54 pm »
Chalk it up to good practice?  It takes way less time the second time.  :)

Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #47November 11, 2018, 11:30:49 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #47 on: November 11, 2018, 11:30:49 pm »
Ok, so the thing that's bothering me about this, is the fact that even though the pump reservoir was full of fuel, apparently the plunger wasn't compressing anything through to the injectors.  AFAIK, the supply pump just draws fuel in to the reservoir and so long as the shutoff solenoid valve is lifted, fuel flows into the plunger chamber--I'm making up my own name for things.  Please correct any assumptions I've made here.

In my case, the supply pump appears to have stopped drawing fuel into the reservoir and the plunger stopped compressing fuel in the plunger chamber, so that's two failure modes.  This seems highly improbable.  When I installed that inline pump into the feed line, it theoretically should've at least addressed the failure of the supply pump, since it effectively filled up the pump reservoir.  The installation of the shutoff solenoid valve without a plunger and spring should've addressed the flow of fuel into the plunger chamber.  So far, I've found no obvious mechanical failures in my pump autopsy, so this all seems rather bizarre and doesn't add up. 
'87 300TD (OM603)-->(OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'94 100CSQ Avant (AAH)

Reply #48November 12, 2018, 10:42:22 am

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #48 on: November 12, 2018, 10:42:22 am »
I see the puzzle.  That's why I recommended attempting to run it from a separate container of clean diesel.  That would eliminate the rest of the fuel system from the equation. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #49December 02, 2018, 01:20:09 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #49 on: December 02, 2018, 01:20:09 pm »
Any further progress on this?
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #50December 02, 2018, 03:14:08 pm

ORCoaster

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #50 on: December 02, 2018, 03:14:08 pm »
Libby, do you think the problem is with the little collar that allows the pump to spill any fuel going to the plunger?  Seems a likely spot to look if the internal vane pump is moving fuel through the body of the IP but nothing is getting to the delivery valves.

Only thing I can think of that would allow front side to work but not have back end spitting fuel.

Now Own 1981 Caddy as the NEW DISTRACTION to all that is around me.  Project Away!

Reply #51December 03, 2018, 04:08:06 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #51 on: December 03, 2018, 04:08:06 pm »
Unless I'm reading the posts wrong, Zeitgeist says that neither the vane pump nor the high pressure pump are working. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #52December 03, 2018, 04:59:21 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #52 on: December 03, 2018, 04:59:21 pm »
Correct, the pump wasn't drawing fuel into the reservoir nor was it compressing fuel into the injector lines.  Despite that, I've found nothing obvious wrong internally.  From what I can tell, the rebuilder did everything I would expect on a pump rebuild, so I don't think I can blame them. 

So far I've started reassembling the bottom section, but then other projects gained precedence over this one.  I hope to start back on reassembly tomorrow or the next.   
'87 300TD (OM603)-->(OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'94 100CSQ Avant (AAH)

 

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