The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (3 Viewers)

[TheBigBoy]

I'm curious why it was suggested not to wind down the star wheel. I find it really helped with off boost power. I can easily pull away from a stop sign in 2nd gear - it makes black smoke, but it pulls while the turbo is spooling.

It may have helped by pouring more fuel down low in. But being 10 clicks from the bottom will mean your side fueling pin and 1/2 to 3/4 of the way into the grind as a starting possition.

You WILL be hitting the fuel restricter very quickly if too deep. It doesnt remove fuel. Just stops any extra fuel from that point. (boost increases, fuel does not)

Here is some pretty pictures to profile everything. For a 1HDT

 

[ForealBoreal]

BigBoy,

If you lived by me I would buy you a beer. Cheers.

That is some amazing data. Thank you for posting that.
If you have any other data on this stuff post it up! I know you do!

I took my boost comp apart again today (its not mounted on the pump yet, brand new from Toyota)
The starwheel took 89 clockwise clicks (to the bottom)

I am curious if I should bother re profiling the rod for my needs.
At this point I am running 14.5-15psi boost.
I know the starwheel's adjustment if going to change in comparison to the boost level one wants to run.
You mentioned 30-40 clicks up from the bottom. Would this work best for my needs?

Would love to hear how different tunes ranging from the 10 to 30psi range affect this adjustment.
Also if its needed to even re-profile.

 

[VK3FHDJ]

The LCOOL instructions where written for adjustments to be made without touching the Main Fuel Screw.

 

[TheBigBoy]

The lcool instructions are also based on all the pumps starting possition being the same. Nearly all pumps I've seen are already wound down far to far.

 

[VK3FHDJ]

The lcool instructions are also based on all the pumps starting possition being the same. Nearly all pumps I've seen are already wound down far to far.

Have the pumps you seen never been fiddled with?

Gotta remember... those instructions came out in the late 90s when the 1HDFT motor was released.. so at the time many pumps wouldnt have been touched apart from being installed.

No one would have worried about Pyros or Boost gauges either and driving around a 1HDFT compared to a 1HZ would seem like being in a Jetcar.

Suffice to say there are allot more people fiddling with the engines in their $80,000 (what a FT GXL cost new at a guess) car these days compared to then.

 

[TheBigBoy]

Yep, that's right Dan. Just making the point that those are outdated and not really relevant anymore. If someone had ever had it tuned. It could already be anywhere.

 

[VK3FHDJ]

All good TBB

Plenty of people start out tinkering with those instructions and get the results they are after. Others of us, want more... then more... then more

 

[sailor]

Agreed. Next to useless currently...

 

[Adam B]

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.

 

[Adam B]

Looking at all the nice detailed measurements makes me wish I had that data before I did it my way...

I did it real scientific like. I marked the aneroid rod with a black Sharpie pen, reinstalled it, hooked up a bicycle pump with an accurate pressure gauge to a hose connected to the boost comp port, and pumped it up to the boost level I was planning to tune for (20psi). I relieved pressure then repeated about 20 times. Removing the rod revealed a nice clear wear line through the ink so I knew exactly what range the pin was riding on. That allowed me to grind enough off the top so that I was on the full diameter portion of the rod and I also shortened up the little spacer ring I described in the last post to allow a bit more downward travel of the rod under full boost while still keeping it off the fuel cut taper. I also tested to about 10 and 15 psi with my pump just to see the rate at which the rod was travelling as boost was applied. As a result I ended up with the preload adjuster set up pretty good before I ever started the engine.

As the saying goes, there's more than one way to skin a cat.

 

[TheBigBoy]

That picture you posted is how I see 99% of them. Wound down almost as far as they can go. Once wound back up the flat starting possition. The fuel screw needs to be screwed in ALOT to make up for the reduced fuel (and idle).

 

[Trock]

BigBoy you wouldn't happen to have the diagrams of the profiles that you posted above for the 1HD-FT?

 

[mudgudgeon]

Good to see some solid info here.
I also found the lcool info incomplete, and only relevant when maximising tune within stock boost limits.
After trawling the net for any info about VE rotary pumps, I did more or less what Adam described, but less scientific
I reground the pin similar to the one pictured above. Doing this allowed me to add about 2turns on the main fuel screw and tune for low smoke at idle and EGTs of 900*c pre turbo if pushed really hard for long hill climbs. Normal driving egts stayed around 650degrees. No idea on AFR, had I known more about suitable AFRs I would have tuned for this over EGTs.

I'd love to be playing with a 1HD-T and Gturbo!

 

[asutherland]

Been on this thread several times due to searches... but finally *subscribed*

 

[Squash]

Fuel Pin Grind

Examples of machined pins from TheDieselShop on youtube.

Denso/Bosch ip in a Cummins...

 

[Tapage]

nice .. nice .. one of those days I will do something radical on mine ..

 

[Squash]

If anyone has a stamped IP number handy I will forward it on and try to nail down an exact fit...otherwise this lazy old man will have to crawl into the engine bay.

 

[ForealBoreal]

I may have a line on the aneroid pins
I just need a 1hd-t fuel pump if plate

 

[ledgend80]

Will they be standard pins or modified pins.

 

[ForealBoreal]

Standard.

Reason behind it is because you can put custom profiles on.

I believe Mark aka BigBoy might have some too.