The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (1 Viewer)
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Ok gentleman I have a few questions for some that may have the know.
I'm to a point on my setup with a well-flowing airbox, front mount IC, 3.5in exhaust and Larger Borg Warner turbo making 23psi that I do not have any more adjustment at my throttle linkage on the intake plenum for the cable or at the linkage for idle adjustment on the pump to decrease idle rpm. Therefore I can not turn my main fuel screw up much more either. Now I could solve both of these issues in various ways but the question I have is... Am I approaching the limit of the pump? Is this a sign I need some pump and injector work? OR do I still have room left to go and I can modify the adjustments to get more fuel from the screw? I'm unsure of how I can test or verify my pump is approaching its limit.
Current observed values:
Pump Timing: 1.30mm, This is actually debatable on if it's correct or not. I am running the old timing spec pre 92 but have the larger post 92 piston bowls and injector seats. Some argue it depends on your pump model for the 1HDT but most will say it was after the piston change. This is why soon I will be going back down to around 1.25mm as I think from memory the advanced side of timing was 1.24mm on the new change.
High Load AFR: 16:1 on the bottom at spool up (1800rpm) and climbing to 24:1 up top at 23psi from turbo around 3000rpm.
EDIT** This is cruise AFR at 65mph up a slight grade and is what I wish I could improve more. At 7-10psi in the intake manifold and 40-45:1 AFR. This turbo at cruise and light load to moderate loads is cold around 700F pre-turbo and even giving it the boot it won't climb much past 900F, I would imagine getting the AFR down to 30-35:1 may help keep some heat in at cruise speeds for me which is 65-70mph. Which if I could turn my fuel screw more I could achieve this I believe.
My fuel pin is custom ground by me and features a very steep ramp to max fuel. I'm doing this because I am attempting to target most of my fuel delivery right around when the turbo is making 5lbs of boost because after 5psi the AFR really leans out significantly. So I have a steep ramp and my pin really starts moving at 3-5psi to max fuel with no fuel cut and the follower pin is not even touching my aneroid pin at full fuel. I am 98% confident my pin travel and spring adjustment method is working well but I am open to suggestions as I am no pro. EGT never goes beyond 1000F at this point and the turbo at 23psi is barely waking up in its compressor map, ideally, the end goal boost for this turbo is 25-27psi with fuel to match. If I had a target AFR at this boost level on this turbo best-case capable of 18:1 but 21:1 at its leanest.
Some of my logic may be incorrect here so what I'm looking for is other routes to go or tuning methods that will achieve better results. OR do I need to plan for custom injection?
I'm to a point on my setup with a well-flowing airbox, front mount IC, 3.5in exhaust and Larger Borg Warner turbo making 23psi that I do not have any more adjustment at my throttle linkage on the intake plenum for the cable or at the linkage for idle adjustment on the pump to decrease idle rpm. Therefore I can not turn my main fuel screw up much more either. Now I could solve both of these issues in various ways but the question I have is... Am I approaching the limit of the pump? Is this a sign I need some pump and injector work? OR do I still have room left to go and I can modify the adjustments to get more fuel from the screw? I'm unsure of how I can test or verify my pump is approaching its limit.
Current observed values:
Pump Timing: 1.30mm, This is actually debatable on if it's correct or not. I am running the old timing spec pre 92 but have the larger post 92 piston bowls and injector seats. Some argue it depends on your pump model for the 1HDT but most will say it was after the piston change. This is why soon I will be going back down to around 1.25mm as I think from memory the advanced side of timing was 1.24mm on the new change.
High Load AFR: 16:1 on the bottom at spool up (1800rpm) and climbing to 24:1 up top at 23psi from turbo around 3000rpm.
EDIT** This is cruise AFR at 65mph up a slight grade and is what I wish I could improve more. At 7-10psi in the intake manifold and 40-45:1 AFR. This turbo at cruise and light load to moderate loads is cold around 700F pre-turbo and even giving it the boot it won't climb much past 900F, I would imagine getting the AFR down to 30-35:1 may help keep some heat in at cruise speeds for me which is 65-70mph. Which if I could turn my fuel screw more I could achieve this I believe.
My fuel pin is custom ground by me and features a very steep ramp to max fuel. I'm doing this because I am attempting to target most of my fuel delivery right around when the turbo is making 5lbs of boost because after 5psi the AFR really leans out significantly. So I have a steep ramp and my pin really starts moving at 3-5psi to max fuel with no fuel cut and the follower pin is not even touching my aneroid pin at full fuel. I am 98% confident my pin travel and spring adjustment method is working well but I am open to suggestions as I am no pro. EGT never goes beyond 1000F at this point and the turbo at 23psi is barely waking up in its compressor map, ideally, the end goal boost for this turbo is 25-27psi with fuel to match. If I had a target AFR at this boost level on this turbo best-case capable of 18:1 but 21:1 at its leanest.
Some of my logic may be incorrect here so what I'm looking for is other routes to go or tuning methods that will achieve better results. OR do I need to plan for custom injection?
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What did you adjust to utilize the full length of the fuel rod?Never been a fan of those LCOOL instructions. All they're doing is telling people how to add a bunch of fuel at various points with almost no understanding of how the aneroid works or what the limitations are.
I'm not going to add much to the tuning details but I wanted to show a photo of the rod that was in my 1991 1HD-T when I first looked.
It clearly shows a deep groove where the follower pin has been riding for a hell of a lot of km. In my case raising the boost didn't cause the pin to ride higher up on the flat or into the fuel cut taper because there was a black anodized aluminum ring around the rod just under the diaphragm that prevented further downward travel. The top of that worn groove is where it hit that hard stop.
Following advice from Graeme and mudgudgeon, and spending a lot of time actually learning how it all worked led me to the (more or less) same conclusions as everyone else who is tuning these things. It now travels from way, way down on the full diameter portion of the rod up to the end of the flat, which has been cut deeper than the original deepest spot. I smoothed out the transitions and put it all back together. I added with the main fuel screw until full boost full load EGTs were where I wanted them, I already had the minimum off-boost fuel I could achieve since I was out on the full diameter portion of the rod, then I tightened up the preload adjuster (star wheel) until I was happy with the level of visible smoke at mid-boost levels. This turbo doesn't spend much time at those levels so I still allow a little bit of smoke when I'm really stomping on it and is working its way up to max. It's pretty minimal and I'm very happy with how it feels right now.
Thanks to this forum ND all u power hungry diesel heads picked up the bits of knowledge to get me started on learning how to tune my 2.5td wlt ute to have egts between 200 to peak of 700 degrees pre turbo running 30psi with all the fuel to match 5k rpm capable ND able to reach its top speed of 180kmph
@CycloSteve , how did this turn out for you? Did you keep it, tweak and tune it more or abandon it altogether? How about anyone else who used the NZ kit for the spacer to get the pin to "ride up" higher? Love it or hate it?A bit more work today. Ground the lip down on the Bosch cover, and installed the barb. Now have a bit more upwards travel with the pin.
Smoke at idle is down, but without adding a restrictor to the line, the boost comes on too quickly. Purchased two Subaru "restrictor pills", one 1mm and the other 1.2mm, and will see how those slow the buildup of boost passing to the diaphragm next week.
Great engine those WL's. They love RPM and really come alive with a tinker on the pump. Mine used to rev out past 5000rpm also
The Bosch plate is still on the truck. Have not tuned it much since the initial install. In any case, it would be simple enough to just adjust it back to factory height if there was any issue.
Good morning,
I'm issues installing my aneroid pin from Torfab. I can feel the fuel pin riding in the groove cut into the aneroid for installation but I have been unable to turn the aneroid pin to the ramp side. It feels as if the fuel pin is stuck in the installation groove. The new pin does seem to be a slightly tighter fit then the original aneroid pin (I have not mic'd to compare). Ideas/thoughts?
I'm issues installing my aneroid pin from Torfab. I can feel the fuel pin riding in the groove cut into the aneroid for installation but I have been unable to turn the aneroid pin to the ramp side. It feels as if the fuel pin is stuck in the installation groove. The new pin does seem to be a slightly tighter fit then the original aneroid pin (I have not mic'd to compare). Ideas/thoughts?
To expand on this ,before inserting the fuel pin, stick a small flathead screwdriver down the bore and push the follower pin towards the front of the truck, THEN insert the fuel pin and you should be able to rotate it as the follower is pushed back out of the way.
I had to remove material with a rotary tool around the diameter of the pin and also on the angle cut into the bottom in order to get the pin to seat correctly. I know the screwdriver trick pushing the follower pin in before seating the anaroid pin but this wasn’t my issue with the torfab pin. Another side note is about 2 months of having the pin installed a deep groove got worn into the pin. It’s not as hard as the material as the oem uses. Go figure.
In other words your better off throwing the torfab pin in the trash and getting a new pin that is going to withstand time. I got some from jh hilux out of Australia.
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I noticed that groove the other day, do you have any more detail on the jh hilux one, is it the same style as torfab's?
No it’s just a stock profile pin but I just used it to grind my own profile on a pin that I knew wouldn’t break down over time. Some of these injection shops can get you blank pins as well so you could grind the entire profile yourself. I have gotten pins from eclipse turbo in AUS and torfab and while they look cool and have a nice profile the pin always breaks down as the metal is too soft.
Is there not processes you could treat the pin with to harden the surface the follower rides on so it won't groove? Have you looked into that at all?
Nah I haven’t. I’m just a garage guy and I found it quite fun to grind my own profile anyways. I’m sure you could treat the pin maybe with an outside source. I get more upset about companies making products that aren’t designed to work as they should. I know many folks have these pins and want to continue using them but why buy a 300 dollar pin just to have to pay to get it hardened so it will work like it should.
I noticed the material was different, definitely not as heavy in my hand. That sucks to hear about the groove. Sounds like I just wasted some $$. So many aftermarket items are just not made well.
If nothing else I'm glad this information is on this thread for others
I communicated with JH hilux through Facebook messenger. Just a FYI as I’m not sure how responsive they may be over email.
Just to be clear the pin I got from eclipse was the same issue of soft material like the one from torfab.
