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Author Topic: Very little boost on my mTDI ALH Vanagon install  (Read 22433 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 (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

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.  :)


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 (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

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. 

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?

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.


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. 

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 (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #53January 31, 2019, 11:06:34 pm

keycle

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Very little boost on my mTDI ALH Vanagon install
« Reply #53 on: January 31, 2019, 11:06:34 pm »
Planning on installing Frantz bypass oil filter on my 471, thinking Im gonna install T where oil pressure line goes to gauge and wondering where to out oil return from bypass filter.  Anyone have experience or advice with these?

Reply #54March 23, 2019, 02:53:19 pm

Chuck1978

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #54 on: March 23, 2019, 02:53:19 pm »
Have you made any progress on this in the past six weeks?
Thank you for posting up those video links, that was very helpful, this is a learning experience for me as well, as I purchased an ALH/Rover mTDI that was never running right.

Reply #55October 15, 2019, 06:27:25 pm

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #55 on: October 15, 2019, 06:27:25 pm »
Ok, I should post some kind of follow up.  This project has stalled due to a lack of time, money or a combination of the two.  Toward the end of summer I pinned everything back up, and got it to fire up of a sort.  It will run so long as I keep working the throttle arm, but it won't idle or really increase RPMs very much.  It smokes and is not a pleasant beast in the least.  I guess I should mention that late last year I pulled the pump and tore it down, though I found no smoking guns or really anything obviously amiss. 

At this point I've added/subtracted so many variables to the diagnostics that it feels like I'm now chasing my tail.  So, I could have a combination of incorrect timing, and/or something not properly functioning in the pump's fuel governing area.  My concern about the former is that I'm still a little unclear about how to ensure a solid confirmation that the hub is properly positioned in relation to the shaft.  I used my dial indicator to set pump timing @ 1.45mm after installation on the engine.  As to the pump itself, I think I put it back together correctly (I mean, at least it fires up now), but there's still a lot of ambiguity about that since I don't have any kind of a manual for reference.

I wish I had a second pump to install and help eliminate some of those variables.  Anyhoo...that's where I'm at with the project.       
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #56October 15, 2019, 07:59:21 pm

fatmobile

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #56 on: October 15, 2019, 07:59:21 pm »
A pulse detector would help you see if the timing is right.
 Using a timing light.
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Reply #57October 15, 2019, 08:46:12 pm

ORCoaster

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #57 on: October 15, 2019, 08:46:12 pm »
When I get the point that you are at with the too many variables thing I sit down and forget everything I did to that point.  Then I ask questions, what is it I really need to figure out first here?

You mentioned this:   My concern about the former is that I'm still a little unclear about how to ensure a solid confirmation that the hub is properly positioned in relation to the shaft.

I am assuming that you are talking about the IP hub and how it is lined up on the shaft.  And if the shaft is on the right cylinder.  If you look at the front end of the shaft with the hub off you have a place for the slotted keyway.  That keyway should be at roughly 10 O'clock position.  If you can tell where the hub slot is without taking it off, then hit the easy button.  If you need to rotate the position of the IP towards the 10 o'clock position then you are talking about a timing reset bit of work.

That is where I would start, verify you are aligned at TDC and the IP is indeed on #1 cylinder.  Once you are sure about that proceed with a normal procedure for doing the timing to 1.05 mm using your caliper stinger.  Not perfect but good enough to get it to idle.

Adjust fuel screw in the back to get it to hit a smooth idle spot and then adjust the stops or the levers on the IP. 

That is where I go when I have done so much I could stand in the drive and twill circles.  Neighbors love it when I do that. 
 

Reply #58October 15, 2019, 08:46:32 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #58 on: October 15, 2019, 08:46:32 pm »
I'm a big proponent of the pulse detector for timing but it will not differentiate between 1 and 4 or between 2 and 3. 

There is a keyway in the pump shaft, hidden by the hub.  That keyway should point toward the delivery valve for the #1 injector when the crank is at TDC and camshaft is also set for the #1 injector. 

« Last Edit: October 15, 2019, 08:48:36 pm by libbydiesel »

Reply #59October 17, 2019, 12:44:25 am

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #59 on: October 17, 2019, 12:44:25 am »
I read the pulse sticky, but the last post was in 2015.  Are there any newer updates for sources or options I should be aware of when I research further?
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

 

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