Full load adjustment question

[csnider]

Does adjusting the Full Load screw for more fuel put more of a strain on the pump or does it just let more fuel flow from existing pump pressures?. . I've been adjusting my pump to fuel later in the boost and less when idleing or at lower boost(around town) and I'm getting good results messing with spring tension and the "smoke" screw... I tried a 1/4 turn in on my full load screw and got noticable results . Increased boost and power when stepping into it but I don't know if this compromises the relaibility of the VE pump. . I don't want to get mine rebuilt again, well soon anyway. . Would I be better off getting the fuel by clocking the fuel pin instead of turning the full load screw? The results I'm aiming at are nice power when I need it and economy while cruising at highway speeds.....

Thanks... ... .

Chuck

 

[Forrest Nearing]

I've heard it does, I've heard it doesn't... I prefer to think that it doesn't and just turn the screw some more



Forrest

 

[Stomp]

Hey I still get 20mpg on the highway. Around town I get 15 or so and my screw is all the way in. Longevity who knows. The reason I had to put a new pump on mine was some of the internal springs broke. It wasnt worn out.



Stomp

 

[BushWakr - RIP]

I think that experience has shown both pro and con applies... . sometimes it seems that your personal "luck" decides this...

I am of the opinion that increasing the demand on any pump will accelerate wear and tear and, in the end, hasten it's mortality... .

A generally accepted rule of thumb is... when the fueling increase (by using the fuel screw) results in noticably higher idle values then you are at the point of increased wear and tear.

If you want to use the fuel screw there is another issue to consider... . when that method is used to increase fueling, it has a tendancy to direct a bit more of the total increase towards the low/low-mid range than the high end... .

This becomes particularly true when using larger injectors.

You can usually get good results by using the specific adjustment for the "range" you want improvement in.

Smoke screw affects the first few feet of launch, say across the intersection... the AFC cone will affect a fairly wide range relatively evenly and, that is moderated by how you set the AFC spring (starwheel). You are correct when you use the starwheel to delay fueling increase till you have more boost; that's what the starwheel is for.

Basically the cone determines the amount of fueling increase and the starwheel determines the "rate" of that increase per pound of boost.



Does that help ?????



pastor bob... .

 

[JLEONARD]

I have my fuel pin rotated to max, installed bigger injectors, and turned my fuel screw in about 1 turn.

Good power, controllable smoke, and I can still get my 24 daily mpg if I can keep my foot out of it. :-laf

But I normally don't so my mileage is down to about 22.

Hope this helps.

Jay

 

[dpuckett]

Jay, I dont want to hear about your MPGs that rival our Celebrity .



One thing that hasnt been mentioned is that you only put wear on the pump when you ask for the additional power. On the highway, it takes x- number of HP to keep it at, say, 65mph, no matter if 160 or 500 is AVAILABLE. I would suggest trying adjustments in and around the AFC housing before breaking into the full power screw. Once you increase the full fuel, you have to go back and re adjust the AFC settings to get the smoke, take off, etc, back where it was.



If you havent read the stickies at the top of the forum, do so. It helps that I have had a VE apart (and it worked when I put it back on, too), and see how it all worked first hand. But, basically, the full power screw determines how far back the spill port comes back (toward the front of the engine) at each plunger stroke, for a given throttle setting. THe farther back the spill port (Pastor, please correct my terminology, as I am almost sure I am using the wrogn word) comes, the more fuel gets injected into the cylinder. Or, the more fuel gets compressed into the storke that goes to the injectors. THAT is what stresses the pump. Now, if your idle increases, and you put the idle back down, it should put you right back where you started, fuelling wise, yet you have more fuel available when you ask for it.



Clear as mud? PM for more details if you really are curious, and cant figure it out from the stickies and my great eloquence .



Daniel

 

[csnider]

Thanks for all the info guys...

And Daniel thanks for explainig the full power screw. . I'm just trying to figure out if the cone turning(tunning) is a better way to get mild performance increases when stepping into it as opposed to the full power screw. . In other words, getting your fueling from the pin that rides on the cone versus the full power screw. . I can get more power by clocking the diaphram in my experiments or more power by turning the screw... I'm just trying to get the best of both worlds: Low boost MPGs and higher boost HP... Maybe one of those custom ground pins is in order?...

MY pump is very reactive to slight adjustments and I always readjust my idle after tweeking it The best MPGs I've ever done was 18. The usual is 15. 5-16. 5 mostly pulling a wells cargo enclosed utility trailer which acts more like a parachute than a weight burden. . I'm sure my transfer case takes a bit of MPGs away too. . Getting 25mpgs would be cool but I doubt I'll see that!

 

[dpuckett]

I'd say start with the AFC cone/ spring tension adjustments, then work in the full power screw if needed. What is your timing set to? You should see better than 18mpg empty. Even *I* get 19 empty around town, with my heavy-ish foot and 4. 10s, and pump that i havent decided what's wrong with. But you have an auto, which can take away a few MPGs, esp if it is getting tired. I got 22 with a W250 with 225K on the trip home. The cargo trailer wont help MPGs, esp if it is little with little tires. They drag more than big ones. I had a 18ft carhauler with 15s that pulled just as hard as a 40ft GN flatbed empty.



-DP