The Official 1HD-T/FT Fuel Pump Mod Tuning Thread

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When I got my truck, it did the same thing. I turned up the boost and adjusted the boost compensator... wow what a difference. I believe that I got a solid 50 wheel horsepower out of those two adjustments. Now, my EGTs are very stable at 1000 degrees, even on long hills.

I bumped up boost first and that brought my EGTs down. After that, I adjusted the boost compensator, turning the fueling rod to the side that had the most aggressive slope. That's where I got the big bump in power... and, after a little playing with it, the EGTs are still the same.
 
Tapage said:
50 wheel HP .. that's a big claim .. !
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It is! But I think it's more a function of my poor starting performance than my current HP.
 
Well I moved the EGT probe to the manifold today, and just in case there was still any confusion, post-turbo EGT's are worthless. I knew I was getting post-turbo readings, so I used 1000 degrees as my limit. Now that I am getting proper pre-turbo readings, I am sure that I when I was reading 1000 post-turbo, I was over 1250 pre-turbo.

In other words, it gets to 1250 pre-turbo faster than it was getting to 1000 post-turbo. At least that is my observation, if someone wants to buy me a second Auber temp probe, I will hook them both up and get some real numbers.

I feel like I am way over-fueled from idle to full load, I can get into unsafe temps at 1/3 throttle, I turned the main fuel screw down 1/4 turn, but didn't notice any difference. I ran out of daylight and will continue tinkering tomorrow.

mudgudgeon said:
I'd possibly run it as is and observe a little longer, you won't kill it in the space of a few days, just keep an eye on EGTs.

Then probably start by backing off the main fuel screw 1/8 - 1/4 turn and optimise the boost compensator settings.
When you're happy you've got it running as good as possible and still got safe EGTs, then you can potentially feed it more fuel.
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What setting has the most effect on pre-boost fueling?

IanB said:
Stock boost still? I'd start with adding a manual boost controller and turning the boost up to 15psi, truck will be much happier at highway speeds with lower EGT's.
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I ordered a controller today, I'm sure it will help out on the top end but right now I can barely even get it to 11psi before my EGT's go through the roof.
 
More boost will help.
When you are teaching 11psi the wastegate is opening to limit the boost delivered.
With the boost controller set to deliver higher boost all that drive energy will be put to use and will lean out the burn resulting in lower EGT
 
IMHO, probe Pre-turbo is the first step, relying on post-turbo EGTs is unreliable. I had post, then pre on the same truck. After having pre, I am pretty certain that in some instances, I thought my EGTs were ok with the probe post, doing the same thing with the probe pre-turbo, I realize that I was probably way too hot.

EDIT: Typing at the same time you were
 
DancesWithMutts said:
I ordered a controller today, I'm sure it will help out on the top end but right now I can barely even get it to 11psi before my EGT's go through the roof.
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I would turn up the boost to 15psi 1st, and reassess your fueling from there. Glad to hear you moved your EGT probe to pre-turbo.
 
I backed off my main fuel screw today, I ended up about 3/8's of a turn back from where it was after going 1/2 turn and it being too much. This seems to have fixed my EGT's being so touchy while the turbo is spooling. I still get fast climbing temps at WOT but I'll wait until i install my boost controller to see how it helps.

I took the top off of my compensator with the intention of pulling the rod, but someone had gorilla tightened the 5mm allens that hold the cap on, one of the heads stripped and I had to get creative to remove it. Is there supposed to be a gasket for that cap? I had no gasket, maybe someone thought over-tightening the bolts would make up for a lack of gasket.
 
Yeah mine were tremendously right as well.
No gasket under there though. I think it seals on the edge of the diaphragm.
I also had to remove a bit of material from a casting in the inlet manifold to enable me to remove the pin from the pump without first removing the diaphragm from the pin.
 
diby 2000 said:
Yeah mine were tremendously right as well.
No gasket under there though. I think it seals on the edge of the diaphragm.
I also had to remove a bit of material from a casting in the inlet manifold to enable me to remove the pin from the pump without first removing the diaphragm from the pin.
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Do you have any pictures of how much material you removed from the manifold? I need to remove the diaphragm from the pin for the same reason...
 
Lumpskie said:
Do you have any pictures of how much material you removed from the manifold? I need to remove the diaphragm from the pin for the same reason...
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Not on me now. But I can grab a pick in the morning.
The further you advance the pump, the worse it will be. I'm currently in the advanced side of spec.
 
Lumpskie said:
Do you have any pictures of how much material you removed from the manifold? I need to remove the diaphragm from the pin for the same reason...
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@diby 2000 has an -FT, where you definitely need to disassemble the diaphragm, or grind the manifold. I am not sure that this would be needed with the -T motor. In anycase, once you have a painted index on the diaphragm (min and max fuel) you should not really need to remove the pin. You can lift it enough to make star-wheel adjustments...as I have recently.
 
Good pick up @CycloSteve.
For some reason I was thinking @Lumpskie had an FT as well.
I do like to remove the pin completely when tuning just to see how far the pin travels into the pump and as a result where the follower is riding on the pin. This is probably not necessary, just me being inquisitive.

Here are some shots of the minor grinding I have done to enable it.


 
diby 2000 said:
Yeah mine were tremendously right as well.
No gasket under there though. I think it seals on the edge of the diaphragm.
I also had to remove a bit of material from a casting in the inlet manifold to enable me to remove the pin from the pump without first removing the diaphragm from the pin.
Click to expand...

Glad to hear that your's were tight and that I'm not missing a gasket.

Big update today, I got my boost controller installed and very quickly realized that I was getting into over-boost cutoff.

I pulled my fuel rod and tapered the bottom for easy re-installation, the existing wear mark indicated that it was going into over-boost cutoff regularly.

My theory is that someone just cranked up the main screw to overcome the fact that the compensator wasn't set up right. The result was me being able to get to dangerous EGT's while driving slowly around town, not even pulling max boost.

I covered the rod in a red sharpie and installed it with the most aggressive profile facing the pin. I turned the star wheel counterclockwise about a half turn and went for a test drive, I was still hitting over-boost. I slowly adjusted the boost controller and the star-wheel until I was getting right to 15PSI and the pin was traveling just up to the over-boost taper. I ended up going over 2 turns counter-clockwise on the star wheel.

I'm pretty happy with everything now, It seems to have almost as much power as it did with it's dangerous tune, but the EGT's are much more manageable.

I want to take a little bit of fuel out of full load/max boost, just to get the EGT's down a little further, should I go further on the starwheel until I'm not getting to the flat spot, or should I turn the main fuel screw out a little further?
 
DancesWithMutts said:
Glad to hear that your's were tight and that I'm not missing a gasket.

Big update today, I got my boost controller installed and very quickly realized that I was getting into over-boost cutoff.

I pulled my fuel rod and tapered the bottom for easy re-installation, the existing wear mark indicated that it was going into over-boost cutoff regularly.

My theory is that someone just cranked up the main screw to overcome the fact that the compensator wasn't set up right. The result was me being able to get to dangerous EGT's while driving slowly around town, not even pulling max boost.

I covered the rod in a red sharpie and installed it with the most aggressive profile facing the pin. I turned the star wheel counterclockwise about a half turn and went for a test drive, I was still hitting over-boost. I slowly adjusted the boost controller and the star-wheel until I was getting right to 15PSI and the pin was traveling just up to the over-boost taper. I ended up going over 2 turns counter-clockwise on the star wheel.

I'm pretty happy with everything now, It seems to have almost as much power as it did with it's dangerous tune, but the EGT's are much more manageable.

I want to take a little bit of fuel out of full load/max boost, just to get the EGT's down a little further, should I go further on the starwheel until I'm not getting to the flat spot, or should I turn the main fuel screw out a little further?
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The flat spot is full fueling, it's the taper where the pin gets wider that's fuelcut. So you want the pin riding on the flat spot at WOT, but not getting into the taper out. The further the follower pin is able to extend, the more fuelling you get. If once that's set up you are getting way too high EGT's, you may find you need to turn down the main fuel screw a bit, assuming someone else has messed with these pump settings from stock and turned it up.

What differences did you notice with 15psi over stock?
 
agreed with @IanB

f you are going beyond the taper onto the flat spot, you are getting the maximum amount of fuel available.
Adjusting the star wheel for more pre-load will delay the rate at which extra fuel becomes available. More pre-load requires more boost to overcome the spring. This might reduce the response on acceleration a bit.

If you are still seeing EGTs consistently getting too high with higher boost, you probably need to take a bit of fuel out with the main fuel screw. Start with 1/8 of a turn, test, repeat.
you might need to re-tweak your boost compensator settings

do you have the stock CT26 turbo?
 
chapel gate said:
Is there any reason not to have the star wheel screwed right down, minimum pre load on the spring, as mine is set?
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With higher boost, you can hit fuel cutoff at higher rpms/boost levels and can run rich down low while boost is building.
 
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