Rickcher

Is there any difference between moving the throttle linkage to the inside hole and backing out the high idle screw versus installing a 366 spring? Do you achieve the same results?

sdstriper

You do not achieve the same results. The spring is better because of the way it works with flyweights in the governor. Under load you cannot get better fueling by just changing the linkage or high idle screw.

wannadiesel

Swapping the linkage just gets you full throttle lever travel without a lot of hassle. The 3200 RPM governor spring makes the pump fuel to higher RPM and also increases throttle response.

Rickcher

Does backing off the high idle screw give you any more rpm or just allow the throttle to advance further?

archer39

it allows for the linkages to travel further. That in conjunction with the 3200rpm spring is where you will see the difference.

Rickcher

Gotcha'. Thanks guys.

sdstriper

Backing off the high idle will allow more "no load" rpm. All pumps are a little different, some may get a little benefit from it but ultimately it's the physics of the spring tension and the flyweights that govern fuel.

Rickcher

So backing off the high idle won't get you any more rpm's under load?

sdstriper

It could, but minimal at best. Like I said, each pump is a little different, but I doubt there would be a significant gain that you would "feel", nothing like the spring change. Nothing to lose really, turn it out.

Riflemanusmc

^x1. Better yet, just take the threaded rod with the two lock nuts out. Will not cause any problems if you do...

Rickcher

Which threaded rod is that?

92smokin blacky

Yeah i have the 366 spring, the throttle lever moved to the inside hole, the high idle adjustment set to the highest, spacers behind my pedal mount, and I bent my pedal a little bit too cuz it was hittin the floor without toppin out, and wow it all made a big big difference!!!! I really like it! None of all that stuff would be really worth it though unless you had the 366 spring in my opinion cuz you wouldn't have the fuel/power at higher rpm. The 366 spring is a cheap/easy mod and it will help a lot! just get one and put it in

PapeCAT

I've had four different VEs in three different trucks, two were upgraded to the 366/3200 spring.

I've spent tons of time tweaking the pumps and tinkering for more than 5 years.

Usually I'd agree with the majority here until I recently started tweaking with my new to me 1993. I've done the piston lift pump and stock fuel pin rotate, + it has a GDS compressor upgrade and a banks quickspool 14 hot side and a bank$ intercooler. MAX boost PSI then was 19ish. Then I removed the high idle screw and got the lever almost touching the pump at WOT.

When I get up to 3000 RPM at WOT my boost climbs to 22ish.... This tells me that the thing is still getting full fuel up through 3000... which is all most of us need. The only reason the boost climbs is because the RPM is climbing... If the boost stayed the same through 3000 I'd say it was definitely defueling.
I haven't tried a no load rev test.

Bottom line is, if you want more than full fuel at 3000 definitely go with the 3200 spring. IF you only want more driveability/shiftability over stock I'd say just remove the high idle fuel screw and see how you like it before doing the 3200 spring because it is a LOT simpler than installing the 3200 spring and leaving the high idle screw in there...

Until someone can produce a side by side bench fuel flow vs RPM chart with and without a 3200 spring test (or similar dyno), everything is subjective to seat of pants 'feel' and driver feelings that the snake oil worked type of thing. Try the easy way first and then decide if you want more.

budsowner

What is the high idle adjustment?

sdstriper

One of the two idle screws on the VE. It limits the wide open throttle travel or no load high idle speed.