The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (4 Viewers)

[mudgudgeon]

You can use the dial indicator to get in the right area before you start fine tuning

I think there's a big difference in setting timing to spec, understanding where it's at, then tuning vs just getting in and giving it a random tweak

If it starts rattling and sounds like you have loose bolts in your rocker cover you've gone to far lol.

Yes it can have serious consequences if you get it wrong

If it's rattling, you've likely got a significant amount detonation happening before the piston reaches TDC on the compression stroke.

This means the pistons are compressing an expanding wall of combustion gas.
This hammers BEB, crank, crank bearings, pistons, and increases compression pressures, so hammers head bolts and head gaskets.

HD-T runs 20:1 static compression ratio, add 24psi boost and cylinder pressures are getting huge, add pre-detonation and you're asking a lot

 

[KiwiDingo]

I think there's a big difference in setting timing to spec, understanding where it's at, then tuning vs just getting in and giving it a random tweak

If it's rattling, you've likely got a significant amount detonation happening before the piston reaches TDC on the compression stroke.

This means the pistons are compressing an expanding wall of combustion gas.
This hammers BEB, crank, crank bearings, pistons, and increases compression pressures, so hammers head bolts and head gaskets.

HD-T runs 20:1 static compression ratio, add 24psi boost and cylinder pressures are getting huge, add pre-detonation and you're asking a lot

Yep, exactly! Definitely don't want that hence my you've gone too far comment

 

[beaas]

About the 1hd-ft, why the differences in timing:

Europe 1.52-1.58mm
Australia 1.37-1.43mm

The euro version has egr from factory (deleted on mine, a euro version with gturbo and more) but there has to be something else that make the differences, it’s a lot isn’t it? I haven’t played with timing yet, acsd still working normally.

What will happen to an Australian ft engine with timing set to 1,55?

 

[IanB]

About the 1hd-ft, why the differences in timing:

Europe 1.52-1.58mm
Australia 1.37-1.43mm

The euro version has egr from factory (deleted on mine, a euro version with gturbo and more) but there has to be something else that make the differences, it’s a lot isn’t it? I haven’t played with timing yet, acsd still working normally.

What will happen to an Australian ft engine with timing set to 1,55?

I believe the different timing specs were related to emissions.

 

[beaas]

I guess there’s more into emission than egr. I deleted egr on mine and it runs perfectly fine. But I guess with timing set to Aussie spec it will not run that good, so what’s the differences? In my head less or no emission means more power or/and better milage.

 

[diby 2000]

My Aussie FT ran at the euro spec timing for a couple of years with no issues, only benifits.
I am intercooled though.

 

[KiwiDingo]

My Aussie FT ran at the euro spec timing for a couple of years with no issues, only benifits.
I am intercooled though.

I'm not sure that cooling actually contributes anything in terms of safety to running a bit more timing. From the little bit of study I did in this area it would actually slightly increase cylinder peak pressures. Reasons I found were due to the cooler intake air being more dense carrying more oxygen which would become harder for the pistons to compress. Then with that increase of oxygen made the flame burn quicker giving off its energy over a shorter duration resulting in higher peak pressures.

I'm sure there's so much more to it than that but it's definitely an interesting subject and very hard to test and get actual data for. The only "testing" I did once was while carrying out other tests and was just an observation I noted when I had my timing a touch too much advanced for my liking which produced a rattle under light load. I removed my cooler with no other changes and noticed that usual rattle had now disappeared. I didn't think anything of it at the time because I was focusing on other things but when I was looking in to injection timing I immediately remembered about it.

 

[chapel gate]

View attachment 2107750
@chapel gate your post would suggest that as the injection system collects miles it loses advance to wear I am assuming. Is that correct?
If that is the case it makes sense that many posters see a benefit to advancing timing on there high mileage engines.
So with a rebuilt pump and injectors on a slightly modifed 1HDT running 24 psi boost, intercooler, modified intake manifold , 3” exhaust, Duramax airbox, fresh rebuild .020”o/s pistons and porting.... What would be a good starting point for for pump timing?
I am currently running .054” of lift just slightly above the stock spec. Should I be considering more advance than that ?

The question is.... is more timing than the FSM acceptable? What is a reasonable limit?

What are factors to consider?

What are signs of too much advance?
I don,t mind experimenting but knowing the limit or how to recognize when you are at the limit is my question.
View attachment 2108218

I have tinkered with alot of the mechanicals on my truck and now the task will be to tune it. I think IP timing and advance curve are probably a good part of the tuning process.

its been the experience of 80 series diesel owners in the uk, that have checked there timing on medium to higher mileage vehicles, that the timing is retarded by the specs shown in the FSM.
personally i would set the timing to the upper specs shown in the fsm.
your obviously the sort of bloke that likes to experiment so ill leave you to find the boundaries!

i have a couple of ts and fts, i also have the sst so ill have a check when i get chance.

 

[Mcreight911]

I would say you are correct on the injector opening sooner so yes advanced.
I wonder if the plunger gets worn in the pump and it bleeds pressure. So it takes more crankshaft rotation to build enough pressure to crack the injectors making the timing late?

As a pump wears it will loose case pressure and thus timing advance on the pump .
Injector springs wear/loose tension and take Less pressure to open so advance timing .

How a pump is built greatly effects where static timing is set . Once u spend time playing with them it will become clear that how it performs is more important than the factory spec . For built pumps follow the builders advice .

They can rattle quite a bit before it becomes detrimental.

 

[KiwiDingo]

Hi everyone,
I am Nick from Steg's Supplies.
I am currently looking into whether our Dynamic Timing Advance spacer kit will work on the Denso and Zexel manufactured VE pumps.
If anyone has any pictures of their pump from the side installed on the Land Cruiser that would be helpful!

mudgudgeon by the looks of the Denso pump you have a "tophat" cover plate with an adjustable screw for the timing advance spring rate correct? So adjusting this would change the rate at which the timing advances with case pressure (and therefore engine speed).
This will probably be set in a similar fashion to the Bosch VE pumps calibration shims using a gauge that bolts to the other side of the pump.

When we install the dynamic timing advance spacer kit on the Bosch pump we also install a shim to maintain the spring preload and keep the timing advance rate as close as possible to standard while allowing the timing piston so travel its full travel within the casing giving us more overall timing advance.
On a standard engine this isnt required but on a modified engine with increased fuelling this allows for sufficient time for the extra fuel to burn completely, reducing smoke and EGTs while giving more bang for your buck.

If I can get my hands on a Zexel and Denso VE pump in the UK I will strip it down and see if my kit will work or whether it will need modification.

Anyone know if any of these timing advance spacer kits got made and whether anyone tried it?

 

[NRS91]

Anyone know if any of these timing advance spacer kits got made and whether anyone tried it?

Hi KiwiDingo
Im still trying to source a pump to dismantle and test on.
I currently have them test fitted on the Bosch VE pump and the VE pump copy that the Daihatsu Fourtrak uses which I believe is a Denso or Zexel but I cant remember which now.

I hope to get my hands on a Toyota pump for testing but they arent that common in the UK.

 

[KiwiDingo]

Thanks for the reply @NRS91. I was thinking that as long as the spacer fitted we wouldn't have to worry about getting your shim to fit as we can use the adjustable spring preload we have on our version to get back to the factory setting. It would just need to be adjusted in the same width as the spacer right?

 

[NRS91]

Thanks for the reply @NRS91. I was thinking that as long as the spacer fitted we wouldn't have to worry about getting your shim to fit as we can use the adjustable spring preload we have on our version to get back to the factory setting. It would just need to be adjusted in the same width as the spacer right?

Yes that would be correct but the shim might be able to be installed inside the piston before the spring. This would give the easiest results with no fiddling.
Just need to work out if there is enough free movement left inside the pump too.

 

[eric888]

I found my pump has a bit different to the one in the thread. Can anyone let me know whether I can do the adjustment(boost compensation) for this pump? Thanks.

 

[mudgudgeon]

View attachment 2191859
I found my pump has a bit different to the one in the thread. Can anyone let me know whether I can do the adjustment(boost compensation) for this pump? Thanks.

Answer should be yes.

Which part do you think is different

 

[KiwiDingo]

Your pump looks no different to every other pump I've seen. The compensator is right there in the center of the pic on top of the pump.

 

[eric888]

Thanks
I found there is the electric stuff connecting to the pump and the screw direction is not direct to front of car!

Do anyone have a good material showing how to adjust the boost compensation? Thanks.

 

[SeaJay]

you may be better starting at page 1 of this thread, and read all 65 pages to get some ideas... and dont fiddle with anything untill you are back to this page

 

[KiwiDingo]

That red circle in the top left is the throttle position sensor, normally only on automatic pumps. I can't see what you are circling on the other red circle though? Got anymore pics of a different angle?

All the info you could ever need plus much more is in this very thread. Take the time and read it all then feel free to ask for any clarification.

 

[eric888]

May I ask can the engine sound can recognize whether it has the pump timing issues?