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  #1  
Old 04-26-2017, 06:13 PM
BluevanACD2005 BluevanACD2005 is offline
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Default More pump adjustment and tuning ...

I know there are a lot of threads out there on this, and I have read most of them. They have me fairly confused though ...

None seem to describe exactly what I have happening: in low rpm, it's easy to get a LOT of black smoke if you push the pedal (pre boost). But once I get into 10-15 psi of boost, it clears up. I want to keep the fuel I have now when I have boost, but clean up the smoke at low rpm and no boost.

What should I change? I have read up on the star wheel, and fuel pin/diaphragm, but still don't quite understand 100%. It seems like I need to rotate the eccentric pin back to the deeper side a little? And then maybe back off the spring tension on the diaphragm to compensate and keep the same fuel when I have boost?

Thanks for the help,

Spenser
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  #2  
Old 04-26-2017, 08:02 PM
anders anders is offline
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Is this on a stock pump or the 12mm pump? You can get a lot more control out of the LDA with the 12mm head.

To maximize the control the LDA has there is some machining that needs to be done and some parts that need to be changed.

If there is black smoke pre-boost you need to back off of the max fuel screw and back out the "smoke screw" on the LDA. The spring in the LDA is maxed at 10psi.
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  #3  
Old 04-27-2017, 05:24 AM
adamdrives adamdrives is offline
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This is the same problem i was having. Backing off the screw on the LDA (top torx screw) solves the problem.
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Old 04-27-2017, 05:35 AM
BluevanACD2005 BluevanACD2005 is offline
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Anders, this is on the 12mm pump I got from you

Thanks for the help, I'll try messing with the screws.
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Old 04-27-2017, 06:01 AM
anders anders is offline
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I would install a aftermarket fuel pin, there is one that I use that I really like, "the hungry diesel" the vender specializes in first gen cummins (VE pumped cummins) his pin is designed well. You won't be able to get the full benifits of the pin, but it will help greatly with the no-boost smoke and still keep some power.
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12mm pump heads, ARP stud kits and GTD nozzles available! http://d24t.com/showthread.php?t=1646
NA intake manifolds and 240 turbo pans for sale.
Need d24 or d24t parts? PM me!
Shipments done on fridays!

1982 242 D24+T/M46- Super pumped! Build thread:
http://www.d24t.com/showthread.php?t=1545
1984 764 D24T/ZF build thread: http://www.d24t.com/showthread.php?t=1734
Diesel parts cars: 82 244,83 244, 84 244, 84 245, 85 745
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  #6  
Old 04-27-2017, 06:40 AM
BluevanACD2005 BluevanACD2005 is offline
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This?

http://thehungrydiesel.com/THD-Fuel-Pin-THDpin.htm
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  #7  
Old 04-27-2017, 07:01 AM
anders anders is offline
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That's it. You can also grind the factory pin, you won't get near the amount of control as the THD pin, but it's free.
When I modify/build the LDA assembly this is how I test them. I have also played with different springs to get 0-30 psi vs the factory 0-10psi.
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__________________
12mm pump heads, ARP stud kits and GTD nozzles available! http://d24t.com/showthread.php?t=1646
NA intake manifolds and 240 turbo pans for sale.
Need d24 or d24t parts? PM me!
Shipments done on fridays!

1982 242 D24+T/M46- Super pumped! Build thread:
http://www.d24t.com/showthread.php?t=1545
1984 764 D24T/ZF build thread: http://www.d24t.com/showthread.php?t=1734
Diesel parts cars: 82 244,83 244, 84 244, 84 245, 85 745
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  #8  
Old 04-27-2017, 07:13 AM
BluevanACD2005 BluevanACD2005 is offline
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I'll give that pin a try... Thanks for the tips!


Spenser
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  #9  
Old 04-30-2017, 05:34 PM
BluevanACD2005 BluevanACD2005 is offline
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I got the new pin today and put it in. Turns out the stock pin was already ground to a similar profile as the hungry diesel pin.

But at least now I understand all the components better. I should be able to tune it now. Seeing them all apart helped, I am a visual person.

I was able to reduce the smoke by reducing the max fuel a little, and taking a little spring tension out at the star wheel to let more fuel come on once I get some boost. I think it helped my EGTs a little too.

I'll drive it for a bit and make some additional adjustments later. Thanks for the help!

Spenser
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