Author Topic: Very little boost on my mTDI ALH Vanagon install  (Read 22399 times)

March 24, 2018, 06:42:48 pm

Zeitgeist

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Very little boost on my mTDI ALH Vanagon install
« on: March 24, 2018, 06:42:48 pm »
I just got my ALH install completed in the last week, but even though it starts and runs very well, it just won't produce any boost above about 3.5psi.  The power output is on par with what I imagine an NA 1.9L diesel would provide, which is adequate around town, but woefully not up to the task on hills or the freeway. 

Here's a pic:



The turbo is a k14 from a 3.0L OM606 that's going into my '87 300TD and only has about 74k on it.  The intake is a very short run, and in fact much shorter than the MB donor.  I've checked the wastegate preload (it's a pressure actuator) and ensured that the wheel turns freely with no wobble.  I was expecting the turbo to be laggy, but not to fail to produce any appreciable boost.  I'm kinda at a loss here.  Thoughts?


'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #1March 24, 2018, 08:38:52 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #1 on: March 24, 2018, 08:38:52 pm »
I should mention that this is a pump from a RR 300TD--11mm head. 

The engine is from an '01 Jetta automatic, and still has the stock injectors. 
« Last Edit: March 24, 2018, 08:42:12 pm by Zeitgeist »
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #2March 25, 2018, 12:16:07 am

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #2 on: March 25, 2018, 12:16:07 am »
The difference between 3.0l and 1.9l is fairly dramatic and the exhaust flow and consequently boost would be proportional.  Do you have EGT gauge installed?  If EGTs/smoke are not unreasonable I would increase the max fuel.  More fuel = more heat = more boost.

Reply #3March 25, 2018, 01:09:17 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #3 on: March 25, 2018, 01:09:17 pm »
Thanks.  I'll work on finalizing the aux. gauge cluster install today and report back.  The wiring is run up front, but the cluster isn't connected yet.  I'll also do some research on how to turn up the fuel on a VE pump.  I've only done that on inline MB pumps in the past.   
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #4March 25, 2018, 04:51:42 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #4 on: March 25, 2018, 04:51:42 pm »


Max fuel screw is circled in red.  It should have a 13mm locknut on it.  The fuel stop solenoid is really easy to touch with the wrench and is typically an unfused circuit, so having the key off is wise.  Turn the max fuel screw in CW to increase fuel.  It is quite sensitive.  1/8th turn is noticeable.  After increasing max fuel you might need to lower idle. 

Reply #5March 25, 2018, 07:37:59 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #5 on: March 25, 2018, 07:37:59 pm »
Thanks, I assume I'll need to remove the crimped collar on that bolt, correct?  Is there a preferred method for removing this without buggering up the threads?
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #6March 25, 2018, 09:33:09 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #6 on: March 25, 2018, 09:33:09 pm »
There's usually a bit of added adjustment available before removing the collar but for a significant change, it will need to be removed.  It is actually tack welded on, so the threads are already buggered at the welds.  :-(  The easiest way I've found to remove the collars is to use a sharp punch right between the collar and the bolt inline with one of the tack welds.  It will usually crack the weld.  Then pliers to pull it off.  Usually there is still more than plenty of adjustment available even before the buggered threads come into play with the locknut.

Reply #7March 25, 2018, 09:35:02 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #7 on: March 25, 2018, 09:35:02 pm »
Two coolant pressure tanks?

Reply #8March 25, 2018, 11:26:07 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #8 on: March 25, 2018, 11:26:07 pm »
Thanks for all the helpful advice.  You were instrumental in assisting me to set up the pump.  The second tank is for the intercooler.  There are two heat exchangers sitting up under the floor on the driver side.  The grey box under the package tray contains the relays for the pump and fan...and glow relay.

Other than the low power issue, I'm really pleased with how well this install has performed.  And with the exception of a few coolant leaks due to inattentive oversights, everything seems to work as designed. The intake is noisy, but the exhaust is fairly quiet.  I wired up the gauges today, but didn't have a chance to drive it yet.         
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #9March 26, 2018, 12:19:02 am

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #9 on: March 26, 2018, 12:19:02 am »
Ah, intercooler.  Of course.  Glad to hear you got it running.  I'm sure you will get the boost issue resolved one way or another.  Not to be a Debbie Downer, but it might take a different turbo, though.  More fuel will make the larger turbo spool faster but you might end up seeing excessive smoke and overly high EGTs before you get it where you would like it to be.  I'll keep my fingers crossed.  Keep posting progress.   

Reply #10March 26, 2018, 01:21:45 pm

Zeitgeist

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #10 on: March 26, 2018, 01:21:45 pm »
Yeah, with this budget build it was the only turbo I had on hand.  I think the K14 was used on other small displacement VAG diesels, so I thought maybe I could get away with running it.  The only other turbo I have is a T3, and I assume that's way too large for this setup. 
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #11March 26, 2018, 02:02:57 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #11 on: March 26, 2018, 02:02:57 pm »
There was a K14 that was used on the VW 1.6TD and 1.9TD AAZ engines, but it is much smaller than the K14 used on the Merz 3.0L engines.  The same is true for the T3.  If you have one that was used on the VW 1.6TD engine then it would be appropriate for an ALH.  If it is off a 3.0L Merz, then it will likely be too large.  Before turbo shopping, though, start with getting an EGT gauge hooked up and adding more fuel and see how that goes. 

Reply #12March 29, 2018, 09:12:06 pm

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #12 on: March 29, 2018, 09:12:06 pm »
Well, I've turned up the pump about a quarter turn, and I definitely get more power, but no boost and just a little smoke.  I'm still having some issues with my aux. gauges, so I've just got the coolant temp and oil pressure gauges to guide me at this point.  Under sustained load the boost rises to maybe 3psi, but there's no corresponding rise in coolant temp.  My gut says that the turbo is just too large for the displacement.  My friend gave me a junk K03 knock-off to use as a template for an adapter, and it's quite a bit smaller than this turbo.  I've done some research and it seems that the K03 or a K03/K04 hybrid are my easiest to acquire wastegate-type turbos.  Is that my best bet?  I'm still on a rather constrained budget, so optimal is probably not in the cards. 
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

Reply #13March 29, 2018, 10:37:55 pm

libbydiesel

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #13 on: March 29, 2018, 10:37:55 pm »
If you get the matching manifold as well, you could run any of the wastegated turbos from the AAZ or mk3 TDI's.  My preference is for the AAZ K14.  It's a little larger and has a little more lag than the K03, T2, GT15 but has better top end power and is small enough to boost fairly quickly.  The K24 or T3 from a 1.6TD with matching manifold would be reasonable on an ALH, but are larger than my preference.  My concern with any of them would be fitment with your intake.

Another option would be to run a VNT15 with stationary vanes and fit an external wastegate to the EGR port.  You can then dial in the desired 'size' of the turbo by adjusting the fixed point of the vanes.

Reply #14March 30, 2018, 01:58:01 am

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Re: Very little boost on my mTDI ALH Vanagon install
« Reply #14 on: March 30, 2018, 01:58:01 am »
I wonder if my 12MM 4BT pump head would make up the difference in fueling needed for this turbo.   
'87 300TD (OM606)
'90 300D (OM602)
'89 Vanagon Bluestar (ALH)
'01 EV Weekender (AXK)
'04 Passat Variant (BHW)

 

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