i fell pray to temptation after installing my pyro yesterday i decided to take the collar of the fuel screw today. first thing i encountered was the threads where the collar was crimped are pretty much toast. does anyone know what die i need to fix that? secondly i turned the fuel screw as far as i could, which isn't that far because of the threads. first thing i noticed is my idle went way up. after fighting with that for a while to get it down to a reasonable level (no tach) i went for a ride....
no difference that i could tell my egt's stayed about the same. seat of the pants, nothing... i was thinking because the idle went up i would notice a improvement? any suggestions? something i missed? even after i fix the threads i don't know how much more idle speed i could adjust. i think my expectations where a little high.

 

You need to take it till you have no more idle adjustment left, then reindex the throttle on the pump one notch counter clock wise. Now the truck will hardly idle at all and you can continue your turning of the fuel screw till runaway gets near. And trust me, it will come. I doubt the threads are anything to worry about, after all they must pass through the locknut before they enter the pump.

From where you're at now to near runaway, if you can't feel a difference then your "seat-o-pants" needs recalibrated.

Edit: you are turning the idle back down using the idle screw correct?

 

my pyro still dosent go over 1000*. the problem is the threads are so bad they won't pass thru the lock-nut. im going to dig up a metric die set.

 

You can buy a brand new fuel screw for $20 from bosch. I'll find the part # and post shortly.

 

Bosch part # for the fuel screw is, 1 463 402 423

 

bradshaw, you can buy the fuel pin from schieds diesel, I just bought one, it doesnt come with the center o-ring so I also bought the gasket kit for the ve
pump for 16.00 dollars, later on if you develope leaks you will already have the gaskets on hand, plus the new fuel screw does not have the stupid collar on it.
hope this helps, shelby aka captcavy

 

is that pre or post turbo? pyro numbers?

 

How many turns is as far as you can turn? Mines as far as it can go without re-indexing the throttle plate and it can go more.
You should have noticed something, maybe your lift pump is dead?

 

If you can't feel a difference, you have something else out of whack.

I can turn my fuel-screw as little as an eigth-of-a-turn and feel the difference.

I had it in 1-1/2-turns farther than it currently is and no other vehicle on the road could pull away from me on a hill; with no other modification whatsoever, that thing was almost scary to drive; I had to really watch to avoid breaking traction.

Alas, with no inter-cooler, and having to pull HEAVY trailers in these KY hills, EGT issues forced me to back it out to where it is now.



By the way, I have a few of those big sets of metric taps/dies and none of the ones I have are the correct thread for the fuel-screw.

In a previous thread, I asked if anyone knew just what thread-pitch/size it is and no one seemed to know.

 

I took the collar off mine yesterday also when I put in a denny T fuel pin and a 3600 spring and gds 60mm turbo w/12cm wastegated housing have hole drilled in web and ported housing. I can only get it to go in until about 3 threads plus lock nut are left and I tried indexing throttle 1 mark counterclockwise but it will not go in any further. It definately has a seat of the pants now but it isn't close to runaway either. I get a little black smoke when first hit throttle and when is wound up and it definately winds alot higher. Haven't hooked up gauges again yet but it will lay rubber after auto catches up but I have only took down the block and back. ( do I need to get a new fuel pin or is there something I could have done wrong in pump so full fuel screw will not go all the way in?
gary

 

the fuel screw is metric thread, m8x1.00

here is the newer style with a hex head, and a part number to boot. expect to pay around $20

 

Where can that be ordered online?

 

what is the average amount of turns you get after removing the collar?
are the ic injectors a limiting factor?
my pyro numbers are pre-turbo

 

some guys can turn the screw all the way in until it stops without reaching runaway, some only take a few turns. every pump is different.

you can order it from any injection shop that handles bosch stuff. i ordered it over the phone from a shop 2 hours away, cuz my local place is full of idiots.

 

Ditto. Mines all the way in and no where close to runaway or max fuel or high EGTs. Some have even welded tips on to the screw but I've heard not to try that.