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

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Yes, the engine note can change considerably from really retarded to really advanced. It can sound really quiet and smooth when retarded but you have bugger all power compared to running more advance. Downsides of this can be engine rattle, vibration and just doesn't sound/feel as smooth.

If you go to far advanced the engine rattle at idle and especially under light engine loads can get really loud and annoying.
 
Do you suspect it has timing problems?

Best approach is to set the timing following the Toyota workshop manual.

If timing is retarded or advanced a large amount, you'll hear the difference.

As far as tuning by ear, an experienced ear can hear a difference in timing, but the difference can be subtle, and an ear can be unreliable.
 
How do we know when to stop turning the main fuel screw? I have probably turned mine 3/4 of a full turn from stock. I now have a lot more fueling that can be added due to recent engine mods (big front mount, big airbox, G Turbo Green). I know EGT needs to be tracked and I do this but I'm worried about a runaway. I read somewhere that if you turn that screw too much it can cause a runaway. My question is how do we know when we have gone too far besides high EGT?

EDIT: Search is my friend i found it in the thread. Cheers!
 
You'll idle will actually kinda pick up the more you do it. Be extremely careful of a run away when doing this though.
The revs i believe hold a bit when you rev it up before coming back down. If it does that you have to back it off.

All the max fuel screw does is advances the fuel curve.
 
Magic Spool Bus said:
How do we know when to stop turning the main fuel screw? I have probably turned mine 3/4 of a full turn from stock. I now have a lot more fueling that can be added due to recent engine mods (big front mount, big airbox, G Turbo Green). I know EGT needs to be tracked and I do this but I'm worried about a runaway. I read somewhere that if you turn that screw too much it can cause a runaway. My question is how do we know when we have gone too far besides high EGT?

EDIT: Search is my friend i found it in the thread. Cheers!
Click to expand...

Maybe get the Torfab (or similar) fuel pin as a next step?

This makes me wonder what's going on with my rig in general... I'm on the stock pin (most aggressive side), running 23 psi on my GTurbo, big PDI front mount intercooler, PDI highflow airbox... and I can still get my EGTs up to 1250 on long, sustained hills. Towing my 22 foot boat, I still have to back off after 10 seconds or so of full throttle.

What do you guys think? I'm on a 2.5" exhaust... would bumping up to 3" or 3.5" make a big difference? I also feel (hear) that my pump timing might be on the retarded end of the spec.... my rig purrs beautifully right now. Do you think bumping up that pump timing would be a good idea for me?

Honestly, I don't really feel like I need more power. My rig isn't "fast" but I can cruise up any hill out here at 80 mph without downshifting (and fully loaded with family and gear... on 35s). But, I'm obsessive about lot EGTs... maybe too obsessive? (I never let my EGTs get above 1250... usually don't let them hit 1200)
 
3" exhaust, including dump, the dump makes or breaks in my experience and check timing, but assuming you're talking pre turbo EGT in degrees F, 1250 isn't an issue.
 
AussieHJCruza said:
3" exhaust, including dump, the dump makes or breaks in my experience and check timing, but assuming you're talking pre turbo EGT in degrees F, 1250 isn't an issue.
Click to expand...

Just so I'm sure... By dump, do you mean the exit from the hot side of the turbo? (basically don't do a 2.5" pipe at the exit which tapers to 3"... do 3 inch all the way)
 
Lumpskie said:
Just so I'm sure... By dump, do you mean the exit from the hot side of the turbo? (basically don't do a 2.5" pipe at the exit which tapers to 3"... do 3 inch all the way)
Click to expand...
By dump I mean the pipe that attaches to the back of the turbine, yep.

I found the greatest difference ditching the factory dump for a proper 3" turbo back system, as in something like this. These guys make a nice product.

www.mantapro.com.au

TOYOTA LANDCRUISER HDJ80 4.2L 1HD TURBO DIESEL WAGON

Complete Manta Performance "turbo back" exhaust system - available in 3" fully mandrel bent aluminised or stainless steel tubing.
www.mantapro.com.au www.mantapro.com.au

I cut off the factory exhaust under the drivers seat and it sounded pretty racy, but didn't do much for the performance. I didn't have intercooler or any of that at the time so it might be less pronounced for you, but imho the first 20" of exhaust, maybe less, is what makes it snappy.
 
Exhaust will probably help a bit but to what extent I don’t truly know EGT wise.
Pump timing advance within spec will probably increase the sound of your diesel while dropping egts a bit. How much again I’ve never compared either ends of the pump spec in terms of plunger stroke. I just set it to the most advanced setting within spec.
Fuel pin tune tune will probably help it out big time though a proper tune might make it feel a hair slower if you are trying to drop your EGTs.
How’s your smoke down low off the line?
You could increase your spring tension a hair to make the fuel pin not travel as deep and not fuel as hard at full boost. Just an idea
 
ForealBoreal said:
Exhaust will probably help a bit but to what extent I don’t truly know EGT wise.
Pump timing advance within spec will probably increase the sound of your diesel while dropping egts a bit. How much again I’ve never compared either ends of the pump spec in terms of plunger stroke. I just set it to the most advanced setting within spec.
Fuel pin tune tune will probably help it out big time though a proper tune might make it feel a hair slower if you are trying to drop your EGTs.
How’s your smoke down low off the line?
You could increase your spring tension a hair to make the fuel pin not travel as deep and not fuel as hard at full boost. Just an idea
Click to expand...


Thanks guys,

I have a 2.5" right now... all the way from turbo back. I can easily upgrade that to 3". I set the preload on my pump almost all the way (star wheel adjusted all the way up) but not quite. I do notice that my EGTs are around 1000 degrees F at 20 psi (or lower down to 15psi. Below 15psi, EGTs are generally 800 or lower). Once I go above 20 psi they climb up. I'll add a 3" exhaust to the list. Does it sound like I need more preload on the star wheel to you?
 
Lumpskie said:
Thanks guys,

I have a 2.5" right now... all the way from turbo back. I can easily upgrade that to 3". I set the preload on my pump almost all the way (star wheel adjusted all the way up) but not quite. I do notice that my EGTs are around 1000 degrees F at 20 psi (or lower down to 15psi. Below 15psi, EGTs are generally 800 or lower). Once I go above 20 psi they climb up. I'll add a 3" exhaust to the list. Does it sound like I need more preload on the star wheel to you?
Click to expand...
It sounds odd that you have the star wheel wound up that high. I finally got around to tuning with a AFR gauge and PYRO. I came up on spring tension just enough to give 17:1 down low when I punch it and I am nowhere near the top of adjustment.

It almost seems like you have the main fuel screw wound up too much. What all adjusting have you done at the pump?
 
Lumpskie said:
Thanks guys,

I have a 2.5" right now... all the way from turbo back. I can easily upgrade that to 3". I set the preload on my pump almost all the way (star wheel adjusted all the way up) but not quite. I do notice that my EGTs are around 1000 degrees F at 20 psi (or lower down to 15psi. Below 15psi, EGTs are generally 800 or lower). Once I go above 20 psi they climb up. I'll add a 3" exhaust to the list. Does it sound like I need more preload on the star wheel to you?
Click to expand...
I’m tuned now at 17:1 down low and 21:1 up top at 25psi. I’m in the same boat if I floor it I can hit 1250 with ease but pulling a 6% grade uphill on long passes at 100kmh in 5th my EGT is stable at 1100degrees pre turbo.

green wheel, torfab box, PDI front mount and 3in exhaust with the factory 2.5 Turbo elbow.
 
Magic Spool Bus said:
I’m tuned now at 17:1 down low and 21:1 up top at 25psi. I’m in the same boat if I floor it I can hit 1250 with ease but pulling a 6% grade uphill on long passes at 100kmh in 5th my EGT is stable at 1100degrees pre turbo.

green wheel, torfab box, PDI front mount and 3in exhaust with the factory 2.5 Turbo elbow.
Click to expand...
Sounds like we have really similar setups... maybe I'll bump a couple more psi up on the turbo as well. Thanks for your numbers and validating that being able to hit 1250 with ease is normal(ish).
 
Lumpskie said:
Sounds like we have really similar setups... maybe I'll bump a couple more psi up on the turbo as well. Thanks for your numbers and validating that being able to hit 1250 with ease is normal(ish).
Click to expand...
But what is your sustained EGT pulling a hill? Is it hard to keep it under 1250 just trying to stay at 100kmh?
 
Magic Spool Bus said:
But what is your sustained EGT pulling a hill? Is it hard to keep it under 1250 just trying to stay at 100kmh?
Click to expand...

I have some long (think grapevine but not as steep) hills on the way to the cabin. I can cruise up that hill at 75+ mph (120+ kmh) and keep EGTs around 1050, just cruising. If I floor it, my EGTs will climb up to 1200-1250 (with outside air temps in the 40s f) and stay there. Once summer arrives and temps are in the 90s, I'd be that EGTs would stabilize 100 degrees or so warmer... just a guess. I'd love to tune so that, in the heat of summer, with it floored up a hill, EGTs end up around 1250. If bumping up to a full 3" exhaust can do that for me, that would be great. If I need a little more boost to do it, I'm fine with that too. I've even considered an intercooler chiller to help during the hottest months. But, I'm guessing I'd have to run an alcohol solution because it's so muggy out here on the east coast.
 
Lumpskie said:
I have some long (think grapevine but not as steep) hills on the way to the cabin. I can cruise up that hill at 75+ mph (120+ kmh) and keep EGTs around 1050, just cruising. If I floor it, my EGTs will climb up to 1200-1250 (with outside air temps in the 40s f) and stay there. Once summer arrives and temps are in the 90s, I'd be that EGTs would stabilize 100 degrees or so warmer... just a guess. I'd love to tune so that, in the heat of summer, with it floored up a hill, EGTs end up around 1250. If bumping up to a full 3" exhaust can do that for me, that would be great. If I need a little more boost to do it, I'm fine with that too. I've even considered an intercooler chiller to help during the hottest months. But, I'm guessing I'd have to run an alcohol solution because it's so muggy out here on the east coast.
Click to expand...

I've heard that a full exhaust can drop EGT's about 100F, but that's comparing to stock, FWIW. I've still got the stock dump pipe on mine as well, it's on the list of things to do. Even if you upgraded to a 3" dump and tied into your existing 2.5" exhaust it would be an improvement, as the exhaust cools the further from the turbo it gets. Full 3" turbo back would be best.
 
Added to my "to do" list. I like that I am getting to the point where I nit pick my EGT in 100 degree increments. I used to cruise at 1100 degrees on the freeway... how far I've come!

Just to be sure... what we're talking about is making the pipe at the flange in this picture larger. I don't have to touch the turbo housing... only the exhaust that bolts to it, right? (if so... that seems easy!)

wmb4yoKh.jpg
 
I never see over 1000egt

Pre-turbo, 3inch exhaust including dump out of the turbo, and 13PSI,

But I live in flat country, curious what I would see with my current setup with some steep climbs. I cant get to my puel pin for now because one of the bolts are stripped pretty bad, one of these days ill cut it off and get in there.

I think my preboost setting is perfect, at start up I get the slightest black puff of smoke.
 
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