Yeah, those tires came on it from Japan. They are not the best but will stay on till they start chunking. I wondered if anyone would call me on it when I took that pic. Which way do I turn the wheel to add preload?
The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (3 Viewers)
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Tapage
Club 4X4 Panamá
counter clockwise to increase spring tension .. increasing spring tension will effectively reduce pin travel which will keep the follower pin on the fueling zone.
chapel gate
GOLD Star
I recently stripped the boost compensator on a breaker i have. There was two washers on top of the spring, they looked stock, colour and size. Anyone heard of this?
mudgudgeon
Resident galah
Yep counter clockwise.
Increased preload shouldn't reduce pin travel, but will delay it until you have more boost to over come the spring tension.
mudgudgeon
Resident galah
Yeah, it was done in later versions.
My 1990 HDJ81 didn't have them.
They limit aneroid pin travel. Effectively a stops the pin going onto the fuel cut side of the taper
Tapage
Club 4X4 Panamá
Went about 20 clicks at a time today and still going into fuel cut at 90 clicks
I think you are both correct.
Adding spring preload will delay the movement of the aneroid into the pump. By doing this the aneroid has to see a higher boost pressure before it will begin moving at all and therefor will not travel as far down into the pump if it sees the same boost pressure as it did with less preload.
Unless your fine tuning the preload, I measure the star wheel movements in complete or 1/2 rotations.
At a guess, looking at the marks the follower pin has made on the aneroid, I'm going to guess you will be at least 3, probably 4-5 full rotations of the star wheel from your initial position before your out of the overboost section.
This is good info, until you've played with things it's real difficult to say how much is a little bit, and how much is a lot with the various adjustments.
That was my feeling as well. I seem to remember people talking about moving 13 clicks on the wheel where I felt that and more did nothing. It would make sense since I have doubled the stock boost.
The interesting thing is in Graeme's tuning procedures he grinds the pin first and then sets the star wheel to move the pin at 3 psi. I don't see how you would not be going into overboost
Maybe Graeme is grinding into the fuel cut giving you more useable pin surface?
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I can't remember Graemes proceedure of the top of my head but I assume he would be grinding the ovetboost section of the aneroid away so it can't ride up into it.
This respectively gives more room for the ramp and removes the ovetboost section at the same time.
I plan on doing the same soon.
Edit.
Sorry, delayed response.
After reading that he does not grind the ovetboost section, only makes the full boost section deeper to allow a larger differential from no boost to full boost fuel.
The aneroid travel seems to be only limited by the spring preload, adjusted via the star wheel.
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mudgudgeon
Resident galah
My thoughts on aggressive vs less aggressive taper on the standard pins has changed.
To me, the taper is the same all around, the difference is the depth of the grind is offset.
In the pic above, if you rotate the aneroid pin so the guide pin is following the left side, you're starting from a base of higher fueling.
Ramp rate is the same.
If you change nothing else, but rotate the aneroid pin, you'll increase/reduce fuel because the guide pin is again a deeper, or shallower grind.
The cam/off idle fuel screw on top fine tunes this. It either pushes the aneroid deeper (more fuel) or lifts it (less fuel).
If you start with the off idle fuel screw with the thinnest part in contact with the aneroid pin (aneroid at highest position) 180° turn takes you from min to max (aneroid deeper), direction of rotation doesn't matter. Interesting that gturbo states this is redundant. It allows a bit of easily accessible fine tuning of the aneroid position without lifting the top cover off
I like the gturbo suggestion of setting the aneroid pin depth so at rest, the follower pin is on the full diameter of the aneroid.
mudgudgeon
Resident galah
The 11 herbs and spices!
I think that's the first time I've seen this posted.
Is it complete?
Some good info there, but it leaves a few questions I think.
You could be right about the ramp rate on stock pins @mudgudgeon.
I have not seen enough of them personally to say one way or another but machining of the pins to have the same ramp rate would be much easier than it they are differnt.
I have not seen enough of them personally to say one way or another but machining of the pins to have the same ramp rate would be much easier than it they are differnt.
I have what I feel is a nicer solution to this issue. I will post up a pick soon.
I did get a hold of it somewhere recently.
mudgudgeon
Resident galah
Here's a pic of the star wheel, and the aneroid pin bushing.
The wheel has maybe 60 notches around it (rough estimate).
The thread pitch is quite fine too. Maybe 1.25mm or (again, an estimate) may be 1.5mm.
If you're making big adjustments, it's far easier to take the aneroid cover off, remove the aneroid and diaphragm and rotate the star wheel from the top. If you remove the aneroid pin, you'll need to grind the bottom edge to get it back in if it hasn't already been ground.
The wheel has maybe 60 notches around it (rough estimate).
The thread pitch is quite fine too. Maybe 1.25mm or (again, an estimate) may be 1.5mm.
If you're making big adjustments, it's far easier to take the aneroid cover off, remove the aneroid and diaphragm and rotate the star wheel from the top. If you remove the aneroid pin, you'll need to grind the bottom edge to get it back in if it hasn't already been ground.
This is my solution to enable the follower pin to ride on the outside diameter of the aneroid.
Has held up past 35psi so far and still retains the smoke screw cam if you want to use it.
Has held up past 35psi so far and still retains the smoke screw cam if you want to use it.
