1HZ-T and 1HDT tuning for beginners? (1 Viewer)

[BreckenridgeCruiser]

I read the pump tuning thread and while I love the depth a lot of people have gone to with profiling their pins in the boost comp, I could not find the basics of how to tune a stock pump with boost comp (added to my turboed 1HZ - thanks @Akella !).

So I know how to adjust the base fuel, low speed limiter (idle) and max speed screw, but how does one get started playing with the tension on the diaphragm in the boost comp? IIRC, the stock pins can be turned and there are slightly different profiles from the factory as you turn the pin?

Lastly, if I take the diaphragm and pin out to adjust the star wheel ( tension on the diaphragm) how do I get the pin back in? I know some have said to grind a ramp on the bottom, but is there a trick to getting it back in without this step?

For more background and more specific advice: the 1HZ has an H55 behind it, still has the fuel collar on the fuel screw on the pump, and has a GTurbo grunter. I am pretty sure I am pushing my diaphragm/pin down to the point where it starts to cut fuel around the 15psi mark. I'd love to adjust it so that I can run 18 and not worry about fuel cut. I assume I need to adjust the preload on the diaphragm with the star wheel and add more fuel with the main fuel screw?

I do have a boost gauge and pre-turbo pyrometer so can use that to assist with tuning. I am not trying to rally the truck, but would love a balance of decent power, fuel efficiency, and acceptable EGT and heat soak into the coolant system .

Thanks in advance! P.S. I did search!

 

[Loober]

I read the pump tuning thread and while I love the depth a lot of people have gone to with profiling their pins in the boost comp, I could not find the basics of how to tune a stock pump with boost comp (added to my turboed 1HZ - thanks @Akella !).

So I know how to adjust the base fuel, low speed limiter (idle) and max speed screw, but how does one get started playing with the tension on the diaphragm in the boost comp? IIRC, the stock pins can be turned and there are slightly different profiles from the factory as you turn the pin?

Lastly, if I take the diaphragm and pin out to adjust the star wheel ( tension on the diaphragm) how do I get the pin back in? I know some have said to grind a ramp on the bottom, but is there a trick to getting it back in without this step?

For more background and more specific advice: the 1HZ has an H55 behind it, still has the fuel collar on the fuel screw on the pump, and has a GTurbo grunter. I am pretty sure I am pushing my diaphragm/pin down to the point where it starts to cut fuel around the 15psi mark. I'd love to adjust it so that I can run 18 and not worry about fuel cut. I assume I need to adjust the preload on the diaphragm with the star wheel and add more fuel with the main fuel screw?

I do have a boost gauge and pre-turbo pyrometer so can use that to assist with tuning. I am not trying to rally the truck, but would love a balance of decent power, fuel efficiency, and acceptable EGT and heat soak into the coolant system .

Thanks in advance! P.S. I did search!

Here is a link to good guide that goes into detail of how a VE pump works and what everything does. I would be hyper careful in tuning a HZ towards performance, plenty of discussions about that on here.

https://legionlandrover.com/manuales/tdi%20tunning%20instructions

To see where the fuel cut is happening, you mark the pin with a sharpie, run it up to your max boost, take it out and you can see what point the follower pin got to. Based on that you adjust the tension of the spring up or down depending on where you want your fuel at your max boost. Obviously you are also monitoring your EGT's, smoke levels, and coolant temps. HZ's do not have a very wide band for tuning before you start getting into unsafe territory. Remember they were not designed to be turboe'd.

To get the pin back in, look down into where the pin goes and you'll see the follower pin sticking out, get a small screwdriver and push it in towards the pump. Apply little pressure on the pin while twisting it back and forth, it will seat. The ramp helps with pushing the follower pin as you are inserting aneroid.

If you need help, come by and I can help you tune it.

 

[BreckenridgeCruiser]

Thanks @Loober for that document. I just needed a refresher on how to ease into the process. I am not trying to tune this for much performance. I just want to get good drivability and the correct air/fuel ratios for the rpm range. My grunter starts building boost just off idle so I know that by the time I hit a higher RPM I am topping out the aneroid pin. I was thinking about starting with tightening the start wheel a bit to get the high end from cutting out and then upping the fuel based on the EGTs.

In the stock boost comp (mine was OEM for the 1HDT), is the aneroid pin symmetrical, or does it have a higher fueling profile on one side versus the other?

 

[Loober]

Its not symmetrical, one side has a slightly steeper ramp.

 

[AussieHJCruza]

This is only my personal opinion, but it's how I would tune a mechanical diesel with a boost compensator that came to me, and assumes pump, injectors etc are in good order and correctly timed.

1) IMHO you need a dyno with the capacity to monitor and plot AFR, ideally adjustable ramp rate and a load dyno rather than an inertia dyno. You want to do the pull in a 1:1 gear (4th assuming H15#) and set ramp rate 5-8 km/h per second for a diesel to get a decent load on it.

2) bit of housekeeping, know where your engine air intake is, and have a CO2 extinguisher or something to block the intake off. I've never had anything run away, but better safe than sorry.

3) set max fuel first. Look for 18:1 to 22:1 AFR, 18:1 for power, higher if you tow to cool the egt a little. If your timing is correct and you're supplying efficient boost, as in not overheated air, you'll be unlikely to have EGT issues at these AFR, but a pre-turbo EGT gauge is mandatory.

4) once max fuel is sorted and idle is back where it needs to be, play with the compensator. I think it's better to fine-tune this on the road, although the dyno can be used to do the bulk of the work. I look for a puff of smoke if you pull off vigorously that clears fairly quickly. My HDJ80 pulled off at 17:1 and above about 1700 rpm ran at 20:1 to the governor - built pump, Gturbo redwheel, 600x400x76 intercooler, 25 psi of boost and timing at 1.3mm lift EGT stabilised about 700c, perhaps slightly lower and was very snappy, brutal torque delivery as she came on boost. Puff of smoke and then visibly clean.

5) Leave the 'coal-rolling' to the TD42 types that need a built engine and 15:1 AFR to make anything resembling decent power. It should be visibly clean, perhaps a light haze at most in daytime. Any non-dpf diesel will be hazy in headlights behind at night. Don't worry about this.

Sorry, fairly roughly put together but hopefully it makes sense.

 

[BreckenridgeCruiser]

@AussieHJCruza Thanks! I am not sure I have access to a Dyno for the first pass, but once I get close I may seek that out to make sure I am running as cool and safely for the power level.

As a question, how is AFR calculated/read and is it a good idea to check this regularly? I remember talking with Graeme about that fact that with the correct AFRs across the rpm span, you can maintain good engine temps, even when pushed...

 

[AussieHJCruza]

@AussieHJCruza Thanks! I am not sure I have access to a Dyno for the first pass, but once I get close I may seek that out to make sure I am running as cool and safely for the power level.

As a question, how is AFR calculated/read and is it a good idea to check this regularly? I remember talking with Graeme about that fact that with the correct AFRs across the rpm span, you can maintain good engine temps, even when pushed...

Have you got EGT and Boost gauges? If so, you can know that you're safe.

AFR is read with a wideband AFR sensor and gauge, be careful if you're buying one though because many of them are designed for gasoline engines and read from ~8:1 to 16:1 which is useless.

A gauge like this will have a bung to weld into the exhaust, a dyno will have a sensor that's put up the tailpipe.

 

[BreckenridgeCruiser]

Yes. I have both boost and egt with the probe pre-turbo. Good to know as I hear that besides EGT, AFR is the best way to tune your truck. I'm just getting into tuning mine and am more looking for efficiency and getting more power, but not at the expense of longevity and engine health.

 

[AussieHJCruza]

Yes. I have both boost and egt with the probe pre-turbo. Good to know as I hear that besides EGT, AFR is the best way to tune your truck. I'm just getting into tuning mine and am more looking for efficiency and getting more power, but not at the expense of longevity and engine health.

AFR is the best way to tune, but on a diesel EGT is the 'safety' gauge.

 

[KiwiDingo]

AFR is just a number and on its own means very little. It's great to know for fine tuning the compensator etc but pre-turbo EGT is so much better for tuning.

 

[Loober]

@KiwiDingo agreed. I installed a permanent one when I started tuning mine, and for our use it really is pointless. I started to use it but the EGT and smoke level became the driving variables. As long as you are happy with power vs EGT vs smoke, doesnt really matter what AFR is doing. I wouldn't recommend installing one.

 

[chapel gate]

i would agree TBH.

some may see boost and EGT gauge as a "lump hammer" way of tuning, but the land cruiser is a lump hammer..

it aint no F1 race car..

 

[BreckenridgeCruiser]

I (and my wallet) appreciate the input! I did find a 24v one but the $300+ pricetag and the large gauge were hard to swallow. I'm trying to keep my dash as stock looking as possible so a pod of aircraft gauges is heading in the wrong direction!

 

[AussieHJCruza]

I wouldn't go to the trouble of installing an AFR setup on a diesel, however I would run it on a dyno for the sake of knowing what the AFRs were, when it was convenient. Long and short: if the EGT are safe, you won't hurt it. Personally, I like to know where the AFR is at, but I wouldn't see any benefit in running a gauge in the truck.

I did have a permanent gauge in my turbo FZJ80 but that's a very different kettle of fish.

 

[BreckenridgeCruiser]

@Loober I'm not sure I can make the BnT Christmas party tomorrow at your place. I was hoping to help you with your vacuum issue while I was there.

I do have a question... I have the pin out and was going to do the spring tension adjustment with ink as you described. I have not touched the pin with the exception of marking it's original orientation. Can the pin be reinserted properly without grinding the base of the pin, or is that necessary for getting it back together?

I live up to my description (breaks things) so I always am cautious before applying pressure to things.

Hope the party goes well tomorrow!

 

[BreckenridgeCruiser]

With @Loober 's coaxing, I used a Dremel to grind and polish a ramp so I can easily reinstall the aneroid pin for tuning. First step was to mark the pin face with a sharpie to see if my assumption is correct that I cut fuel when my turbo gets above 15lbs.

I didn't change any settings yet so this will be a current state check to see how the spring tension is before I start rotating the pin to adjust the profile and fuel load across the boost scale.

With the GTurbo, my thought is that getting the right spring preload should be the priority before playing with the aneroid pin rotation and main fuel screw.

 

[BreckenridgeCruiser]

So I did two tests with the spring adjusted a bit. Both seem to be travelling only very little on the pin. To note, I do have a spacer and a washer that sits on the shaft of the pin. I will probably pull those out for the next test.

Also, the cam is set to its lowest setting (meaning. The aneroid pin should be able to lift higher on low/no boost.

So what's going on here?

Another angle, but you can't see the lines as well as in the first picture

The ramp I cut to get the pin back in. Goes in very easily. You can see the washers/spacers in the background

Also, I was driving with boost from 0 to over 15psi (gauge tops out at 15) I didn't spend much time over 12psi but hit the fuel hard a few times to get that pressure up to hit 'max' boost

 

[IanB]

To me, it looks like you aren't getting into fuel cut, and you could LOOSEN the star wheel spring adjustment to allow for more pin travel. Before doing that though, you mentioned there's a spacer and a washer on the pin that would limit travel, I'd run without those to see how far the pin travels with no restrictions and make sure it won't be your bottleneck before you start making changes.

The cam in the lid of the boost compensator adjusts where on the pin the off-boost fueling is, and it sounds like yours is maxed out right now. Backing it off so the pin sits higher in the compensator body at rest means less fuel off-boost, if that's what you're trying to accomplish.

 

[BreckenridgeCruiser]

@IanB that's what I was thinking. I removed the spacers and did a test with a bike pump to see if I get more travel. After about 15 pumps to 20psi and back to 0 I could see a fainter line that made it to the full boost area (but not to fuel cut).

I unwound the star wheel 7 clicks and reinstalled the pin and will test drive today. I loosened the spring tension a bit more since I don't think I'll get to 20psi and max out around 17 with how I drive. Plus my bike pump gauge was not very precise so I am sure I may have gone a little over 20psi a few times.

The off boost cam is actually set to the lowest setting (thinnest, so applying the least downward push) so I can't get it to allow for more upward travel without modifying or removing the cam. If I can get the drivability I want, without smoke, then I'm cool with less upward travel.

 

[BreckenridgeCruiser]

Drove it for a while today. Thought I was hitting the max boost/fuel cut, but I think I was just set a little lighter on the fuel somehow. You can barely see the line where it hits the flat part before the fuel cut, but it still starts partway up the face and not on the flat. I guess that is okay if it drives well.

The boost was slightly lower today, but the power was more linear. Almost like it drove better across all RPMs, bit needs a little more fuel overall. I have not messed with the main fuel (smoke) screw yet as I would like to see if I can tune the engine without removing the OEM collar and keeping the stock fuel setting (I know... I'm weird).

I adjusted the spring tension a bit lighter to see if I can get a little more fuel earlier without hitting fuel cut. Will drive tomorrow and post up results.