The Official 1HD-T/FT Fuel Pump Mod Tuning Thread
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Flat highway at 110kmh 15 psi. Small rise and she bounces to 25psi
Working on my tune now that I have reconnected the BACS and SICS on my 1HD-FT. After doing this, the IP was definitely over-fueling, producing more soot, and thus wasting fuel.
This is what I have done so far:
1. Tested the IP diaphragm per the FSM, which failed. Installed a new one.
2. Setup the star-wheel to the factory height, raising it six clicks.
3. Turned the aneroid pin 45 degrees from full fueling.
I have yet to touch the smoke screw, or the main fuel. EGT's are still low, and power is improved.
Next steps that I am looking at are simply turning the star-wheel up and down and logging the effects, and also rotating the aneroid. Boost pressure is around 20psi, and I will be installing a manual boost controller next week (Dawes), and also upping the boost on the GTurbo GX. Also contemplating adding an O2 sensor bung so I can log data with my Innovate LM-2.
This is what I have done so far:
1. Tested the IP diaphragm per the FSM, which failed. Installed a new one.
2. Setup the star-wheel to the factory height, raising it six clicks.
3. Turned the aneroid pin 45 degrees from full fueling.
I have yet to touch the smoke screw, or the main fuel. EGT's are still low, and power is improved.
Next steps that I am looking at are simply turning the star-wheel up and down and logging the effects, and also rotating the aneroid. Boost pressure is around 20psi, and I will be installing a manual boost controller next week (Dawes), and also upping the boost on the GTurbo GX. Also contemplating adding an O2 sensor bung so I can log data with my Innovate LM-2.
Boost controller installed and set at 24-25PSI now. A bit too much fuel down low, and not enough up top.
Worked on first getting the off-idle smoke under control. Tossed my AFR sensor up the tail pipe since I have not had the bung added yet. Raised the star wheel quite a bit, and now at 18.5 at idle with little/no smoke on stabbing the throttle sitting still. Will need to have the data logger fully functional to do more testing on the road and rotating the fuel pin for more up top.
Worked on first getting the off-idle smoke under control. Tossed my AFR sensor up the tail pipe since I have not had the bung added yet. Raised the star wheel quite a bit, and now at 18.5 at idle with little/no smoke on stabbing the throttle sitting still. Will need to have the data logger fully functional to do more testing on the road and rotating the fuel pin for more up top.
Hey guys. Sorry if this is too off topic (Im not cool enough to run a 1hdt) but a lot of what ive learned about my 5lt pump has been from reading up on other pumps so maybe you all can help. This seems to be the tuning thread after all.
My 5lt seems to be running super lean at idle and low load (even with my off boost cam on the top of the boost comp rotated to full depth)(according to my AFR guage) runs a good ratio and egts at about 1/2 throttle, but jumps way too rich and hot beyond half throttle especially uphill or under load. If i baby the throttle its alright, but i could cook the engine quick if i punched it hard for long.
Any advice on increasing low end fuel and decreasing high end fuel? Should I shim the aneroid pin so it wont drop so low? and then turn up the fuel? Or turn down the fuel and somehow up the low end fueling further?
Thanks
Lars
My 5lt seems to be running super lean at idle and low load (even with my off boost cam on the top of the boost comp rotated to full depth)(according to my AFR guage) runs a good ratio and egts at about 1/2 throttle, but jumps way too rich and hot beyond half throttle especially uphill or under load. If i baby the throttle its alright, but i could cook the engine quick if i punched it hard for long.
Any advice on increasing low end fuel and decreasing high end fuel? Should I shim the aneroid pin so it wont drop so low? and then turn up the fuel? Or turn down the fuel and somehow up the low end fueling further?
Thanks
Lars
how much boost are you running?
best way to think about how your pump works is that a boost compensator reduces the amount of fuel delivered to your engine. It restricts fuel delivery when its not needed, and allows fuel delivery to come back up toward maximum fuel delivery as boost rises.
being able to reduce the fuel delivery at idle and off boost allows you to potentially increase the maximum amount of fuel available at high load, full throttle scenarios because low end over fueling is no longer an issue.
If your EGTs are out of control under high load conditions, you need to get the EGTs under control first by either reducing maximum fueling, or increasing boost.
adjusting off boost fuel and the aneroid settings are kind of a separate issue. increasing low end fueling wont help reduce peak EGTs
best way to think about how your pump works is that a boost compensator reduces the amount of fuel delivered to your engine. It restricts fuel delivery when its not needed, and allows fuel delivery to come back up toward maximum fuel delivery as boost rises.
being able to reduce the fuel delivery at idle and off boost allows you to potentially increase the maximum amount of fuel available at high load, full throttle scenarios because low end over fueling is no longer an issue.
If your EGTs are out of control under high load conditions, you need to get the EGTs under control first by either reducing maximum fueling, or increasing boost.
adjusting off boost fuel and the aneroid settings are kind of a separate issue. increasing low end fueling wont help reduce peak EGTs
The one thing I could add to the above post is to rotate your pin to a less aggressive slope and basically start again.
You may have to increase spring tension to limit how far the pin travels into the pump on boost which will decrease the difference between no boost and full boost fuelling at the expense of fuel ramp rate.
You may have to increase spring tension to limit how far the pin travels into the pump on boost which will decrease the difference between no boost and full boost fuelling at the expense of fuel ramp rate.
Thanks for that explanation @mudgudgeon! I was thinking about the role of the aneroid pin totally backwards. Also, I realized i was envisioning the process too much like a gas engine. Without a butterfly valve in intake/throttle body, of course the truck is going to run super lean under low load. The engine is gonna push about 3 litres of air whether im at quarter, half or full throttle right?
Anyway, I dialed back the main screw about 1.5-2 turns and then worked my way back up a bit till I could punch the gas and hit an AFR of about 21. Then I reduced about a turn of preload off my clicky wheel and got the boost fueling to jump a bit faster and improve boost performance.
End result so far: AFRs stay between 21-25 with the skinny pedal pinned, and my EGTs will only hit 1000 if I leave it pinned uphill for a while. Im hitting about 7psi.
Theres definitely room to improve over the next few days of testing, but Im happy with the progress ive made. Id like to hit 8-10 psi, but im not totally sure how to up the boost further without upping the heat.
Oh, and @diby 2000, my aneroid pin is semetrical on this pump, so I cant really play with the ramping rate unless I upgrade or bust out the grinder. Im not quite confident enough with my tuning skills to commit to the grinder just yet
Anyway, I dialed back the main screw about 1.5-2 turns and then worked my way back up a bit till I could punch the gas and hit an AFR of about 21. Then I reduced about a turn of preload off my clicky wheel and got the boost fueling to jump a bit faster and improve boost performance.
End result so far: AFRs stay between 21-25 with the skinny pedal pinned, and my EGTs will only hit 1000 if I leave it pinned uphill for a while. Im hitting about 7psi.
Theres definitely room to improve over the next few days of testing, but Im happy with the progress ive made. Id like to hit 8-10 psi, but im not totally sure how to up the boost further without upping the heat.
Oh, and @diby 2000, my aneroid pin is semetrical on this pump, so I cant really play with the ramping rate unless I upgrade or bust out the grinder. Im not quite confident enough with my tuning skills to commit to the grinder just yet
@advlars yep, you are correct, engine speed and power is controlled by the amount of fuel available to burn.
For a diesel, start by forgetting everything you know about tuning gas engines. More fuel = more combustion heat.
sounds like you made a good start.
boost will be limited by the amount of drive energy available (hot combustion gases) and by the wastegate.
if your wastegate is set for 7psi, you won't see boost above that.
if your wastegate is set to open at higher psi, and you're still only seeing 7psi, then you might need to tune in more fuel
For a diesel, start by forgetting everything you know about tuning gas engines. More fuel = more combustion heat.
sounds like you made a good start.
boost will be limited by the amount of drive energy available (hot combustion gases) and by the wastegate.
if your wastegate is set for 7psi, you won't see boost above that.
if your wastegate is set to open at higher psi, and you're still only seeing 7psi, then you might need to tune in more fuel
I'm confused by the behavior of my 1HD-T powered FZJ. It's acceleration is incredibly low. I have to floor it to accelerate from 50mph to 60mph on flat ground, for example. (I thought I would get acceleration with 50%-75% throttle on flat ground) My rig has a Gturbo Grunter and my boost gauge is showing 15psi. I don't see any black smoke coming out of the tail pipe, but my EGTs shoot up to 1200 just trying to keep up with traffic to get onto the freeway. When diesels run rich, do they make poor power? From the GTurbo thread discussion, I decided to get a manual boost controller and was considering bumping up boost 5psi to see if that lowers the EGTs and increases power. But, from your comment above, it seems like a rich mixture wouldn't cause lower power, just high EGTs. Do you have any advice for me?
Thanks,
How does the trans shift? When I first picked up my '91 HDJ81, the kickdown cable was out of adjustment, meaning you had to floor it to get a downshift, and get the turbo to spool up. Made it nearly dangerous to drive, it was a complete dog. If you manually shift the auto does it make it any better to accelerate to freeway speeds without the EGT's soaring? Where is your EGT probe located?
At what RPM does the turbo come on boost? Mine seems to make boost around 1600rpm for reference.
Is you boost gauge accurate? Eg. does the orange overboost light come on in the cluster when your gauge is showing 15psi? If not, you probably aren't boosting 15psi.
Ok. You guys are good.
1. Now that I checked for smoke during real daylight hours, there is some. A big bellow on initial accel tha trails off. My exhaust exits to the rear so there may be more I can't see.
2. @IanB I think your right. In drive, I can't get it to shift after 2500 rpm... how donyoy adjust the drop down cable?
Thanks for the help you guys,
1. Now that I checked for smoke during real daylight hours, there is some. A big bellow on initial accel tha trails off. My exhaust exits to the rear so there may be more I can't see.
2. @IanB I think your right. In drive, I can't get it to shift after 2500 rpm... how donyoy adjust the drop down cable?
Thanks for the help you guys,
Have you double checked what transmission you have? Did the PO swap the A442F that came with the 1HD-T, or have you still got the stock '96 trans (A434?)? Assuming you've got the A442F, is it the fully hydraulic ('90-92), or the electronically controlled ('93+) version?
Here's the page from the service manual ('92, so fully hydraulic version) on how to adjust the cable, small adjustments can make a big difference here. If you have the newer electronically controlled version, the adjustment specs may be different, FYI.
Here's the page from the service manual ('92, so fully hydraulic version) on how to adjust the cable, small adjustments can make a big difference here. If you have the newer electronically controlled version, the adjustment specs may be different, FYI.
@Lumpskie as general rule for diesels, more fuel means higher combustion temperatures. With no throttle on the intake, engine speed and power is governed by the fuel delivery (quantity, and timing)
With a turbo diesel the increased fuel (greater volume of expanding combustion gases) and higher combustion temperature provides energy to drive the turbo.
increased drive energy helps provide more boost and more air through a denser air intake charge, which then increases AFR and reduces EGTs. You can then potentially add more fuel for more power (within limits).
too much fuel at the wrong time will cause EGTs to rise. (the IP mechanically governs fuel delivery separately to throttle position depending on engine RPM to help control this)
with any given amount of fuel, adding more boost = more air into the intake, higher AFR, cooler combustion temps.
BUT, there is limits. Tuning is all about finding the balance, compromising between raw power, sustainable combustion temps and engine longevity and economy (within reason)
some more info about your setup would help. Is the truck new to you?
does it have 3" exhaust, intercooler? fresh injectors? has the pump been tuned by someone who knows what they are doing?
checking some basics wouldn't hurt.
Is the air filter good?
air intake un-obstructed?
is the fuel filter good?
is boost gauge accurate?
after that. look at the fuel pump tune.
if you jab the throttle hard with the car in neutral, you should see an initial puff of dark smoke, but it should be abrief puff that subsides as engine RPM rises.
when driving, if you accelerate hard from a standing start, or accelerate up a hill, I would expect to see a puff of smoke on initital acceleration, and a bit of a dark haze (not a cloud) through the lower RPM, but reducing as you get up into mid-high RPM.
it can be hard to see the smoke from drivers seat.
If you have a sustained dark puff of smoke, you're overfueled and EGTs wil rise.
With a Gturbo, it should most definitely "get out of its own way" as you put it. Even at 15psi, the Gturbo should be delivering a much greater volume of air than a stock turbo.
As a guide, it should pull strongly from around 1800-2000 rpm upward, and should still be pulling strongly beyond 3000rpm. I found mine with mild hiflow turbo started to run out of puff around 34-3500rpm, but while power did taper off, it still made power beyond 4000rpm.
Also,
Is the injection timing correct?
are the injectors good?
have a look at the youtube videos on IP tuning, there's a couple a few page back in this thread that are a pretty good guide.
With a turbo diesel the increased fuel (greater volume of expanding combustion gases) and higher combustion temperature provides energy to drive the turbo.
increased drive energy helps provide more boost and more air through a denser air intake charge, which then increases AFR and reduces EGTs. You can then potentially add more fuel for more power (within limits).
too much fuel at the wrong time will cause EGTs to rise. (the IP mechanically governs fuel delivery separately to throttle position depending on engine RPM to help control this)
with any given amount of fuel, adding more boost = more air into the intake, higher AFR, cooler combustion temps.
BUT, there is limits. Tuning is all about finding the balance, compromising between raw power, sustainable combustion temps and engine longevity and economy (within reason)
some more info about your setup would help. Is the truck new to you?
does it have 3" exhaust, intercooler? fresh injectors? has the pump been tuned by someone who knows what they are doing?
checking some basics wouldn't hurt.
Is the air filter good?
air intake un-obstructed?
is the fuel filter good?
is boost gauge accurate?
after that. look at the fuel pump tune.
if you jab the throttle hard with the car in neutral, you should see an initial puff of dark smoke, but it should be abrief puff that subsides as engine RPM rises.
when driving, if you accelerate hard from a standing start, or accelerate up a hill, I would expect to see a puff of smoke on initital acceleration, and a bit of a dark haze (not a cloud) through the lower RPM, but reducing as you get up into mid-high RPM.
it can be hard to see the smoke from drivers seat.
If you have a sustained dark puff of smoke, you're overfueled and EGTs wil rise.
With a Gturbo, it should most definitely "get out of its own way" as you put it. Even at 15psi, the Gturbo should be delivering a much greater volume of air than a stock turbo.
As a guide, it should pull strongly from around 1800-2000 rpm upward, and should still be pulling strongly beyond 3000rpm. I found mine with mild hiflow turbo started to run out of puff around 34-3500rpm, but while power did taper off, it still made power beyond 4000rpm.
Also,
Is the injection timing correct?
are the injectors good?
have a look at the youtube videos on IP tuning, there's a couple a few page back in this thread that are a pretty good guide.
Thanks for the reply, you guys.
@IanB I didn't double check in person but, according to Tor and the previous owner, they swapped transmissions with a brand new Wholesale Automatics A442f with a heavy duty torque converter. Honestly, I can't tell what transmission is under there from looking under the truck but I'm willing to take their name for it.
@mudgudgeon
Good feedback. Yes, I've have the truck in my hands for only 2 days now but I did get some history from the previous owner and Torfab. Here's what I can tell you:
Injectors were cleaned by DFIS about 2000 miles ago
Diesel pump was rebuilt by DFIS at the same time
I haven't checked the air filter but will tomorrow
Need to check fuel filter
I don't know anything about injection timing... I need to learn
I don't know if boost gauge is accurate but 15psi makes sense since the previous owner was boosting this amount when he had the turbo installed on his 1hz that ended up dying.
For smoke, there is definitely a decent puff of smoke when I accelerate from a stop, then it clears out. I get good acceleration from 1800-2100 rpm then it drops off quickly after that. By 2400 rpm acceleration is very slow and rpms don't want to climb. If I floor it from a stop, RPMs will climb and the truck will accelerate better through 3000. But, if I accelerate lightly from a stop, then floor it, the truck will accelerate very slowly.
If I only use 50% throttle, the truck feels really good. Turbo spools quickly and it feels perky. But, if I want to accelerate any faster (say 75% throttle) nothing really happens. If I floor it, I get a little more acceleration but not too much difference from 50%
On flat ground, cruising at 50 mph, I get an EGT of 800.
Once I hit a hill, EGT goes up to 1000.
Does any of this make any sense to you guys?
@IanB I didn't double check in person but, according to Tor and the previous owner, they swapped transmissions with a brand new Wholesale Automatics A442f with a heavy duty torque converter. Honestly, I can't tell what transmission is under there from looking under the truck but I'm willing to take their name for it.
@mudgudgeon
Good feedback. Yes, I've have the truck in my hands for only 2 days now but I did get some history from the previous owner and Torfab. Here's what I can tell you:
Injectors were cleaned by DFIS about 2000 miles ago
Diesel pump was rebuilt by DFIS at the same time
I haven't checked the air filter but will tomorrow
Need to check fuel filter
I don't know anything about injection timing... I need to learn
I don't know if boost gauge is accurate but 15psi makes sense since the previous owner was boosting this amount when he had the turbo installed on his 1hz that ended up dying.
For smoke, there is definitely a decent puff of smoke when I accelerate from a stop, then it clears out. I get good acceleration from 1800-2100 rpm then it drops off quickly after that. By 2400 rpm acceleration is very slow and rpms don't want to climb. If I floor it from a stop, RPMs will climb and the truck will accelerate better through 3000. But, if I accelerate lightly from a stop, then floor it, the truck will accelerate very slowly.
If I only use 50% throttle, the truck feels really good. Turbo spools quickly and it feels perky. But, if I want to accelerate any faster (say 75% throttle) nothing really happens. If I floor it, I get a little more acceleration but not too much difference from 50%
On flat ground, cruising at 50 mph, I get an EGT of 800.
Once I hit a hill, EGT goes up to 1000.
Does any of this make any sense to you guys?
does the trans kick down a gear when you floor it?
if it's not shifting down to a lower gear, you'll have a high load on the engine, but low torque through the trans. It might explain slow acceleration, and would also explain why your EGTs are high.
You'll see high EGTs in a situation where you have full throttle, high load, low RPM because you are dumping a lot of fuel into the engine, but not getting the air through the system.
an example is climbing a steep grade in a high gear, or pulling a load up a grade.
I'd suggest test what happens if you hold the trans in a lower gear and try some full throttle runs (preferably up a hill) and see what happens.
see if it pulls past the 2500 mark, see if EGTs still climb high.
or at highway speed, manually shift down a gear and give it some acceleration and see what happens
I forgot to mention... I did try holding the gears back with the shifter. I could get thr rpms to climb and had better acceleration. EGTs were still just as high though.
Maybe adjusting transmission and more boost are both needed?
Maybe adjusting transmission and more boost are both needed?
yeah, sounds like some more boost definitely wouldn't hurt.
By the way, 1200*F (~650*C) is well within safe limits for your EGTs for this engine. 1200*F would be a moderate tune, ~1300*F (~700*C) is widely considered safe.
I personally was happy to push mine to a max sustained EGT of around 1380*F (750*C), and peak of 1475*F (800*C) if really pushed hard. Many would consider this too high, however mine was tuned to that level for around 18 months - 2years and regularly pushed hard. I had it apart after a turbo failure and there was absolutely nothing to indicate this level of tune was too hot.
I personally would not blink an eye at your 1200*F EGTs.
By the way, 1200*F (~650*C) is well within safe limits for your EGTs for this engine. 1200*F would be a moderate tune, ~1300*F (~700*C) is widely considered safe.
I personally was happy to push mine to a max sustained EGT of around 1380*F (750*C), and peak of 1475*F (800*C) if really pushed hard. Many would consider this too high, however mine was tuned to that level for around 18 months - 2years and regularly pushed hard. I had it apart after a turbo failure and there was absolutely nothing to indicate this level of tune was too hot.
I personally would not blink an eye at your 1200*F EGTs.
That's really good to know. The boost controller will come in the mail on Monday. Maybe I'll try installing that and bumping boost up to 20psi. After I see what happens, I can either mess with air/fuel more or try adjusting the transmission.