1hdft pump tuning

[frank rabbets]

Thanks Shayne.......not sure, I was hoping for some tuning info on the 24 valve motor.

 

[hopeless wanderer]

I posted up on another thread about an idea I have for my 24v, Mines slightly different in that the turbo boosts to 25psi. Is yours standard Frank ? I am going to be looking for a guinea pig for a new long travel pin that takes the starwheel out of the equation. You turn the starwheel as far in as it will go and fit a new pin and spacer and away you go.
Someone on Mud has already had the same idea, I have the spacer and the pin in the pipeline and I'm gonna test some springs to see which will suit the pin best so the starwheel becomes irrelevant

 

[Shayne]

Maybe this will help Frank https://www.landcruiserclub.net/community/threads/4-2-td-fuel-pump-tweakage-some-useful-info.128718/

 

[Grimbo]

Loads of people seem to be "Tuning" their 4.2's either 12 or 24 valve by just boosting more and playing with fuelling .
When we were messing about with rally cars first thing was to lighten and balance flywheel to get it to rev quicker and lessen stress on the crank . Also gas flowing heads etc went hand in hand with twin 48's ( or quad 48's on my TR8 ;-) )
Anyone actually removed the engine , stripped it and blueprinted it before then porting and lightening , and then looking at boost and fuelling ? .
Anyone who has played in a RIB fitted with the marine versions pushing close to 300hp will find it revs quickly and certainly has no lack of power with a standard turbo .....yes you would never keep 300hp cool on the road but the engine is pretty much the same ......just injectors and fuelling plan on the pump I think and a lighter flywheel with no clutch .
Take the pump off your 24 valve , send it to your local diesel shop telling them it's for a Yanmar Marine engine and see how the cruiser runs when you get it back

 

[frank rabbets]

Thanks for the link Shayne. That's not the one in the above post but very useful. Mines totally standard 24v and nobody has touched the pump. I tried a few little tweaks but no difference to the flat spot below 1800 rpm.

 

[Road runner]

Interesting post RR. Do you have a direct link? I can't find it for the life of me.

Thats the link - great vid from a dude who knows the right stuff!

 

[Road runner]

Sorry - see you have a 24v. I had one years ago and it went like a scalded cat. No flat spot anywhere. But it was a manual and kms were around 150. Whats yours? How many kms you have on the clock? I think 2 or 300 kms for these trucks is reasonable but without the service history you are not sure of whats done and whats not - My "flat spot" was really more of a skip or hesitation. If I powered through the rev range past the 1750 mark no evidence. But if I was labouring up a long hill with trailer on there would be a small repetitive hesitation like starving of fuel. When the air filter was changed it was less noticable but still there.

 

[Shayne]

Round town where 30 mph is an unlikely goal i rely on momentum and blind faith when it comes to a hill that my 24 valve unmolested 80 will actually keep moving . Sometimes though when the planets are aligned just right i will make it over a crossroads without slowing down much and halfway up the next hill there will be a surge of power as she races to the stop sign 100 yards ahead .

 

[frank rabbets]

Sorry RR but still no link. Am I blind ?

Mines got 165k miles from new and I've had it from almost then.

 

[Road runner]

Thanks Shayne.......not sure, I was hoping for some tuning info on the 24 valve motor.

See post from cptsideways. Dude has experience and a resurgent 24v engine. He sums up the problems and solutions real clear. Good luck!

 

[nielsc]

I came across this mod for the VE pump:

What is a Boost Ring & do they work on Land Rovers? | 4Mud

How to install a Dynamic Timing Advance Spacer kit | Steg's Supplies

Basically it is a spacer that gives more travel to the dynamic advanced timing plunger in the pump wich advances the timing at higher revs for a better combustion.
Apparently it is a popular mod with the cummins and landrover crowd.
I also noticed my 1HDFT pump has an adjusting screw there.
Anyone have done this mod or played with the adjusting screw?

 

[Shayne]

A good right up but i'd much sooner hand my truck to "Cooma Diesel" as the writer did in the end - if i could find such a place i could trust with it .

1HD-FT Performance Adjustments

The '95 - '98 multi valve factory turbo diesel motor (1HD-FT) is a great motor with gobs of go and gobs of torque. Because however it has a larger turbo housing and is tuned for tight emissions, the off boost response is light. This can be alleviated with simple injector pump adjustment. It's not a difficult task and the results are impressive indeed.

Adjustments are required to three components of the injector pump and does not affect the factory seal on the maximum injection volume screw. Adjustments are required to the boost compensator characteristic tendency and to the maximum off boost injection volume screw.

Boost compensator characteristic tendency

The stock boost compensator characteristic tendency on the injector pump is set very conservatively on this motor. This can result in lack lustre performance until you get the boost wound up. It varies quite widely from car to car and I've driven a couple that were quite bad down low.
The boost compensator is the diaphragm that sits on top of the fuel pump. On the rear face (towards the rear of the car), just under the diaphragm is a 12 mm bolt (from memory) with a rubber drain cover/tube covering it (Aussie spec only. The European models have that BACS tube in there). Pull the rubber cover off and undo the bolt. Depending on which tools you use, you may have to remove the fuel inlet pipe first. It's tight in there....

Inside the hole is a toothed wheel sitting on the horizontal plane. You can see it if you grow a 3rd hand, shine a light in there and hold an inspection mirror just right. You don't need to see it though.....

Insert a smallish blade screw driver (holding the blade in the vertical plane) and get it on the teeth of the toothed wheel. Now push the end of the screw driver away from the motor (to turn the wheel clockwise when viewed from above). As the wheel turns, you'll hear a faint click as each tooth pushes against a detent spring. You need to turn it 2 or 3 clicks.

Re-install everything being careful not to over tighten the bolts. They screw into soft aluminium.

What this tweak does is to allow the pump to inject more fuel at low to moderate boost pressure. It doesn't affect the maximum injection volume, so you're not over stressing the motor. Another benefit is that it'll pull harder as it approaches red line. There's no noticeable difference in smoke and the net effect is better economy. You'll end up shifting sooner and not having to rev the motor to get going quickly.

Don't be greedy however by screwing it down much further. The gotcha is that it does inject more as the boost drops close to red line and you can get alarmingly high combustion temperatures when revving hard for any length of time.

Maximum off boost injection volume

This adjustment determines how much fuel is injected when there is no boost. Once boost begins increasing, the boost compensator characteristic tendency described above takes over. By increasing the volume of fuel injected, there is more torque available under no boost conditions with the added bonus that with more fuel, more exhaust energy is available to spin the turbo up quicker.
The adjustment screw is found on top of the boost compensator diaphragm and usually has a dab of yellow inspection paint over it (it may however have flaked off with engine washing

Make a note of its stock position for reference. To adjust, loosen the lock nut and screw the adjustment screw in. Initially, turn it in half a turn and tighten the lock nut.

Now it's a matter of trial and error. Warm the engine up and test the adjustment by looking for a light puff of black smoke as you hit the accelerator from idle. You can repeat the procedure and keep increasing the adjustment half a turn at a time until you do see an increase in smoke.

Try to keep the smoke to a minimum when you do finally find a screw setting that suits your engine.

This will have a noticeable effect in the off idle response and can have the turbo spinning up and boosting right down from 1,000 rpm.

A word of caution however. With all this new-found torque at low boost, don't be tempted to lug it up long hills simply because it now can. Bearings don't like being hammered.

I did this mod to mine 6 or so months ago and jumping into a stock TD now it's noticeable just how different it is.

Boost Compensator Profile

For those a bit more adventurous, there is one more adjustment (other than the main set screw

that can have a significant affect on low to mid RPM torque.

The boost compensator is essentially a diaphragm that pushes a pin down as the boost pressure increases. The above two operations alter the pin's off boost position and the spring's preload.

The pin itself is tapered and the taper angle changes depending on the angle the pin is on. This pin is bolted onto the diaphragm itself so rotating the diaphragm also rotates the pin and presents a different profile to the pump.

Access to the diaphragm is fairly simple - remove the 4 allen key bolts on top of the boost compensator.

Mark the position of the diaphragm in relation to the housing it sits in. This gives you a reference point of the original position. Rotating the diaphragm clockwise as you view from the top increases the amount of fuel delivered from idle to close to maximum RPM. Max fuel is determined by the main set screw.

You can rotate the diaphragm past the max point. This now begins to reduce the fuel delivery. There are no markings to show where the maximum point is however you can feel where this point is.

Rotate the diaphragm with your eyes closed (this is important) and feel the point where the tension is the least. Mark that point and perform that operation again to confirm the position. The diaphragm should be in the same position.

I have seen one pump where the diaphragm was set to the maximum position from the factory - leaving no further adjustment. This is uncommon.

Cheers
gc
The week before last, I visited Dave Webster at Cooma Diesel in Fyshwick (in Canberra) to discuss our vehicle and some rather sluggish behaviour in low-end acceleration. They test drove it for me and said that it was indeed sluggish and that it definitely needed attention in the fuel-pump. They said that whilst in factory-spec, the spec was wide in its tolerance and mine was in the very very lower end of "acceptable".

They arranged for me to contact Toyota (which I did) and review the vehicle for work to be carried out under warranty. This I duly was granted, and did without my truck for three days whilst they (Cooma diesel) worked on the fuel pump on behalf of Toyota.

The results? Unbelievable. There is heaps more power/acceleration from 1,000 rpm to 2,500 rpm and there's more top-end power too. Before nothing so much would happen over 3,500 rpm; now... much more acceleration and power. It's a different vehicle...

What Cooma Diesel did was to re-calibrate the fuel pump and run it up on the dyno to make sure it was at its optimum. They didn't touch the injectors, or spray patterns or anything like that, just re-calibrated the pump. And all done under warranty - the cheapest upgrade I have ever had.

For those who own the 1HD-FT (esp. if it is still in warranty), try what I did - it could give you a huge boost...

BTW, great service from Cooma Diesel - extremely knowledgeable and very helpful.

 

[Shayne]

And because i can't read this pic really does simplify exactly what grinding the pin is all about - i'm lazy

Has me wondering if adding a boost controller and grinding the pin to allow suitable fuel at max boost would give this engine the sort of urgency driving experience i get fro my 90 .

In effect it would make the turbo on/off max boost or nothing . Your thoughts please ?

 

[nielsc]

I have done all that, added more fuel with the max volume screw and a “performance LDA pin wich is just cut deeper, also boostcontroller at 1 bar and a big intercooler. It goes quite well! Just under 1800 RPM I’d like more boost but then I would have to go to a hybrid turbo.

 

[Shayne]

Yeah mines fine at speed its getting up to speed i need to fix . I'm just idle right now and toying with the idea that a boost controller to the compensator might sort of make the turbo kick in all at once if you get what i mean ?

I can't get my head around it right now but would boost pressure build faster if there was no extra fuel to burn it off ?
What if max fuel was dumped in only 1psi below max boost ?

Idle thoughts idle thoughts ...................

 

[nielsc]

You need extra fuel to make the turbo boost more and faster, but the ability to boost more and faster is limited by the design and geometry of the turbo so at a certain point you cannot gain more without produce too much smoke and heat. If you don’t mind tractor pulling smoke then it’ll boost quicker.

A boost controller needs to be placed in the pressure line that runs from the inlet manifold to the wastegate actuator.

 

[Shayne]

I know where it goes i have one on my 90 , i'm talking about a second one .

The turbo will spool even if the fuel is set at its leanest , i've tried it on my 90 , felt like the clutch was slipping because there was no fuel to match the boost .

I'm wondering if the turbo takes so long to kick in because it initially struggles to keep up with 6 greedy cylinders , and so if by preventing the fuel recognizing boost with another controller until an effective pressure is realized might it seem like the turbo cuts in quicker even if we still have to reach 2000rpm ?

 

[Shayne]

Thanks for the link Shayne. That's not the one in the above post but very useful. Mines totally standard 24v and nobody has touched the pump. I tried a few little tweaks but no difference to the flat spot below 1800 rpm.

Hey Frank my 24 valve is bog standard , only time i thought to test mpg was a long distance week and it took so long to empty the tank i started thinking the fuel gauge might be broken , and then i forgot to record the miles when the fuel light finally did come on

It might interest you to know that a 3 inch turbo back exhaust has improved things a lot , i haven't touched the pump yet . I've only done 5 miles in it since fitted and in town traffic so i can't decide if the turbo cuts in earlier or the revs just build faster so the turbo cuts in , but either way there's no hesitation any more .
There's few hills around this town i'd got used to using momentum to get up while the engine labored hard to get nowhere fast , suffice to say each one took me by surprise today and had me hits the brakes

 

[frank rabbets]

Thanks Shayne. Where did you get the exhaust from?

 

[Shayne]

Hi Frank Charlie at Prospeed in Cardiff made it (himself) and though it did take him much longer than agreed due to personal problems it was worth the wait . Typically you drop your car off at 9am and drive away at 5pm by appointment .