Mainset screw on a 1HD-ft pump....... issues.....

[1UZ-LUX]

Hi Lads

Just intercooled the 80 and need to throw some more gas at it.

The friendly Toyota engineers put a real dumb anti tamper sleeve over the Mainset screw thread and crimped it in place.....Dicks!

What I want to know is can I take the whole main set screw out or does bad shit happen inside the pump?

It will be way easier to get the darn thing off if I can take it right out.

Cheers

[Petemcc]

I used a combination of pliers and screwdrivers... it eventually came off.

[Trundle]

As above or use a dremel with a small tungsten carbide ,
The fuel screw isnt really the best way of tuning as it only changes your total fueling from idle right through to redline ,
Total fueling is done via the shimms above the pins on the compinsator diagphram , Coming onto boost fueling is done via the ratchet system on the anroid , and your ram is adjusted via rotating the pin (you will se that it is elongated , You can reduce your idle fueling via the pretension on top of the diagphram , 4mm allen key i think it is ,
Make sure your timing is in check before you get to carried away , i believe its 1.18mm on a 1hdt but if you want to know exactly i can check my spec book ,

[1UZ-LUX]

Cheers Trundle I did know most of that already and coincidentally learned about the shims a couple of hours ago.

Have so far given all those things a tweake except for the shims. It seems it was tuned pretty mild so all those adjustments havent yet made the gains I want and my EGTs are still way low. Havent been too aggressive yet and just doing it all in stages.

Will give the shims a go and see where we are at. How many shims are there and how many would you take out?

Just to give you an idea of room to tune I cant get my EGT to get hotter than 550.(pre turbo) Foot on the floor in 5th from 80kph through to 140kph.

Towed a 3+ ton boat from Taupo to the Bay and I couldnt get EGT much above 550 as it was so heavy and I couldnt go fast enough up the hills

I have a pretty good sized Intercooler so theres definately room to chuck in a shitload more fuel.

[Trundle]

If you remove the pin how far down is it traveling , also how much boost is being run etc , ? It depends on the shim thickness really , My offroader runs none with the pin on the deepest part but it has a Big arse holset and does put a bit of black smokeout coming onto boost ,
Theoretically on a road truck you kind of should be taking your AFR ratios into account if you are concerned about fuel economy ,
Also remember the pumps in the cruisers have a fairly big plunger so make sure you mark the pin or write down what you have done to it so you can put it back to std

[1UZ-LUX]

AFR ratios? I do want some form of economy as well. I get close to 700k a tank at the mo which is quite nice after 350k in my V8

Its running 14psi at present as well. Will let you know how far down the plunger its running.

[1UZ-LUX]

Turns out it had no shims.......

Needed to add a washer as the plunger was going down too far and de-fueling.

Set plunger to its widest point.

Got the stupid sleeve off with a chisel was easier than I thought....

1.5 turns on the fuel screw so far performance is definitely getting better and is now boosting to 16psi due to the extra fuel.

5th gear 80kph-140kph egt gets to 630.

[Trundle]

The shim or pin top should be about 6-6.2 mm from the top , the deeper it travels into the taper the more gas you will get and as you said if you go to far it will hit the top ,
You can get some trick pins from overseas with custom ramps in the pick attatched ,
You can also grind yours or extend the flat and get it re- hardened,
It sounds like your egts are getting close to the comfortable limit also ,

[turoa]

You can also grind yours or extend the flat and get it re- hardened,
It sounds like your egts are getting close to the comfortable limit also ,

They aren't hardened, just polished. Did a mild custom grind on mine and its made a hell of a difference!

[Trundle]

If you add a washer to the top (undo the nut and fit it , ) it will make it travel even further ,
The only way to restrict the total travel is to add a plastic shim to the top of the ractchet mechanism to stop it going so deep ,,
It only takes 10psi boost for the pin to travel to the bottom of the taper ,
I use marking blue and do some driving or a vivid to ensure its not bottoming out at the end of the taper but it can be calculated via some basic measurements ,

Attatched is the pick of the plastic shim that stops the travel

[suzolla]

That looks like a Nissan one, both my toyotas have 1 or 2 little black (steel I think) washers. He has put a washer in the same place to restrict travel. The boost at which full travel occurs will depend of the height of the star wheel under the spring
Cheers
Tim.

[Trundle]

yes within reason though as unless you have a aftermarket spring they are usually fully compressed at 10psi , if you put to much tension on the star wheel it usually results in coil bining/ bottoming out ,
This is all my finidings other peoples opinions may differ etc etc