Pump adjustments needed when upgrading from 3.2 to 3.8 spng?

[meby]

For you guys that have tried the various springs, which one allows full fuel up to 3500ish?

What is this mini max setup you speak of?

I'm planing an air shutoff with my twins so when I get my pump completely screwed up I can still shut the mess down.

I've had the 366 spring in two trucks now including my current one and they'll both spin up to 3500 rpm pretty easy. When I get into mud, slick streets, etc, it'll spin 3500 rpm before I have time to blink.

[ahale2772]

how is a propper re-indexing done to take up the slack of the longer spring?

[oldestof11]

. . .. without actually pulling on the gizmo (raising the fuel).

That's the hard part. Keep it mind not all pumps are the same. Many don't respond well to threading the fuel screw in a bunch in order for the truck to idle at a reasonable rpm. Then not take off on it's own when you apply throttle.

NOTE: That gizmo that the throttle tugs on with the spring, is also influenced by the fuel-screw and the governor mechanism.

I've forgotten more than I ever knew, but I'm pretty sure the gizmo is called the tensioning lever. Again, not all pumps are the same. There are quite a few different tensioning levers out there. I'm not pointing this info at you BC, I know you understand it, more towards the rest that read this.

Sorry Jon, but I just had to sit back and laugh inside when you got back from your 4200rpm spring maiden run only to say it defueled or felt like it did at what, 2500-2800rpm, BTDT .

I'm waiting on someone to try the min-max (VW) governor spring setup for competition applications, not necessarily for dyno purposes.

So that was you? Dam you!

I have a VW pump with the caged gov springs. I even know how to tune it for 6500 or so RPMs. Hmm. Also might try the pump top as it is AFC-less. Iirc, the big spring gets shimmed for max RPM and the smallest for idle. The intermediate is there for dampning when you floor it.

[cmann250]

how is a propper re-indexing done to take up the slack of the longer spring?

I've not done this, but i have put some thought into it. I figure after marking the throttle index in the stock position twist the shaft as if you pressed on the gas pedal. You'd probably have to play with it a bit +/- a tooth or two with the same caution you would excercise after tweaking the fuel screw or putting in the 3200 spring.

Makes sense in my head at least

[fatty]

how is a propper re-indexing done to take up the slack of the longer spring?

The same way as when you forget to mark the throttle index. Play with it until it works.

[shiftycapone]

Just cut the damn spring! Its a little spring, some good dykes/snips will handle it no problem. Why anyone would want to screw around with re-indexing when one can just cut to the proper length is beyond me. I orederd a 354 (4200) spring and it will be going in this weekend to replace the 366 spring. Needless to say, its getting cut.

[rattlebox93]

Clipped 354 spring is whAt? amazing going from the clipped 354 to stock 366 i bet its 100hp loss no sthi my truck is an animal with the 354 spring and 6x16s with the 366 and smame injectors it dont run any better than with my pods

[fatty]

Just cut the damn spring! Its a little spring, some good dykes/snips will handle it no problem. Why anyone would want to screw around with re-indexing when one can just cut to the proper length is beyond me. I orederd a 354 (4200) spring and it will be going in this weekend to replace the 366 spring. Needless to say, its getting cut.

Because getting the spring to the EXACT length isn't that easy. Those springs are made of very hard material and it can be difficult to bend a new hook.

[Tsbourne09]

Just cut the damn spring! Its a little spring, some good dykes/snips will handle it no problem. Why anyone would want to screw around with re-indexing when one can just cut to the proper length is beyond me. I orederd a 354 (4200) spring and it will be going in this weekend to replace the 366 spring. Needless to say, its getting cut.

Because getting the spring to the EXACT length isn't that easy. Those springs are made of very hard material and it can be difficult to bend a new hook.

Agreed! Note my wanted ad... Lmao

On indexing its from left 2 lines down and right 2 lines up. Wht it was for mine. Good place 2 start.

[oldestof11]

Ask Andrew to bend that spring. I about left SOP with a stocker if it wasn't for him.

[shiftycapone]

Alrighty then boys

[BC847]

Y'all keep in mind: Basically, the spring is located between the throttle-lever, and the gizmo that moves the spill-port collar. When setting the throttle-lever indexing, you're basically wanting to take-up any slack between the throttle/spring/gizmo, . . .. without actually pulling on the gizmo (raising the fuel).

The 3800prm spring is in fact a little bit longer than the 3200rpm spring (stock spring too IIRC). It's been my experience that:
- If you're wanting to stay with the original throttle-lever indexing, you're gonna have to shorten the 3800rpm spring to match the original spring.
- If you don't shorten the 3800rpm spring, you'll have to re-index the throttle-lever so as to have full throttle available.

Make sense?

NOTE: That gizmo that the throttle tugs on with the spring, is also influenced by the fuel-screw and the governor mechanism.

The typical governor spring in the center, throttle lever to the left, "Top-Hat" assembly to the right. That's the main fuel-screw to the upper-right of the Top-Hat assembly. That's the throttle-lever you're moving around indexing it to the shaft just above the number 3.



What-ever spring you put in, just make the spring fits with the change in lenght. The longer spring would need at least one more spline counter-clockwise.




NOTE: I personally back the main fuel-screw out three or four full turns when making changes to the throttle-shaft indexing. Once indexed where I want it, I then turn in the main fuel-screw 1/2 turn with each attempt to start the engine. You'll eventually have the engine try to idle (though stumbling) if not idling close to good.
Now adjust the main fuel-screw as you would otherwise. Run it in to maintain a maximum EGT at sustained WOT, our turn-up the flame to just before Run-Away.
If you run the main fuel-screw all the way in and your mess won't try to run-away? Then back the main fuel-screw out three or four turns, and re-index the throttle-shaft one more spline counter-clockwise. Now run the main fuel-screw in 1/2 turn at a time as before.


* I still have my fuel-kill pull-cable in my hand just in case. By now all of you should know how fast your engine will wind-up. You should be able to tell, when the engine first hits and turns over once or twice, if it's close to a normal idle, or headed to the moon. Just switch it off while pulling the cable it if even grins wrong at you. If you're here, in this site, in this thread, you should know the business-end of a wrench. There's really no excuse IMO for a run-away situation to occur if you do the main fuel-screw adjustment as I do. I've never had mine run-away, and yes, I've since found that spot where, with blipping the throttle, I'm thinking: Yeah, sure is slow at unwinding.

I'm waiting on someone to try the min-max (VW) governor spring setup for competition applications, not necessarily for dyno purposes.

This is similar to what Bill's talking about. Instead of a simple governor-spring like we run, some VW applications use this type of governor assembly which actually has two springs as mentioned above. As I've read in the VW forums, it's common practice to shim the springs to raise the rev-limit.

Again, this image is only typical . . .




I'm gonna put together a thread directly of the typical VE fuel throttling (including the AFC) with more images like this.

[Hansen01]

so if you cant reach runaway all you have to do is reindex it?
i dont think dads is even close to a runaway with the screw in as far as it will go lol (93 cummins)

[BC847]

so if you cant reach runaway all you have to do is reindex it?

Yup, just back out the main fuel-screw three or four turns (ensuring no guaranteed immediate run-away), and advance the throttle/shaft index one spline (moving the shaft counter-clockwise).
Then attempt to start the engine by creeping the main fuel-screw in 1/2 turn at a time till it comes up to idle. (If you've backed the throttle minimum stop screw all the way out in an attempt to have access to a full throttle, you may have to tighten or loosen the throttle bell-crank rod to establish your desired idle speed).
Otherwise run the main fuel-screw in till you're happy.


The only way I see you can get a run-away situation is to have the fuel control set to not allow the spill-port sleeve to uncover the port as needed to slow the engine for the lack of additional fuel to the injectors.

[Hansen01]

alright that what i thought you were sayin, thanks