92smokin blacky

I'm a little worried that my truck will runaway once I put my 4200 spring instead of my 3200 spring in. I started it up last night in the cold and gave it a little throttle to warm it up to about 1,000 rpm then I held it there for a while and then it started to go up very slowly to about 1200 rpm then it would just take off and rev way up real fast from there til I let off. It will do that when its warm too but it usually wont move up slowly from 1,000, but as soon as it hits 1200 it just goes out of control til I let off again. I still got my pull cable too but I've heard that even those won't stop them sometimes, Do they make air shut off gates that you can run with a filter instead of an open turbo? I've already got a 3200 spring in there and got my full power screw cranked way in and have already blown the shut off solenoid but fixed it by grinding it down like it says in the sticky. I'm kinda worried if puttin the 4200 spring in will make it runaway? Or will it just do the same thing?

dieselJon

4200 might. Now, you could back out the screw 1/4-1/2 turn and give a little fun up for great security.

Onemoparnut

What is the reason for going to the 4200 spring?

92smokin blacky

Same reason as any other mod more fuel, more power, more rpm/top end. And I'm just really curious what it will do. If I don't like it, I'll put the 3200 back in.

jimbo486

The amount of fuel being delivered will remain the same. What will change is the point at which the governor will begin to cut fuel and the only thing you'll gain is more RPMs and some top end.

Onemoparnut

I thought that the ve didn't like to fuel much over what the 3200 spring would let it spin to. Are you going to change the valve springs?

thrashingcows

That was my understanding as well. Over 3000rpm your basically making noise...very little gains?

JBradley500

IMO anytime you mess with the governor mechanism you should be ready for a possible runaway. I'd back it off 1/8 turn if youre that close anyway.

92smokin blacky

Yep gonna order studs and valve springs as soon as i get some stuff sold and get them in, I think I'll put it in when I'm ready and have my intake off ready with a board.

I'm thinkin about putting a butterfly valve like a choke in my intake pipe so I can shut it down if it ever ran away while driving, if i had a manual I would just dump the clutch in 5th, but with my auto its a little different story even though i still have my pull cable.

Onemoparnut

I don't think the pull cable will help a runaway either will it?

jimbo486

3300rpm is the magic number I've heard from others who've had their pumps benched. At that point fuel begins to taper off. But if it's running away, it doesn't take much fuel to keep it turning. Nothing will stop runaway except for cutting off the air flow and if you're lucky, oil won't be getting sucked past the rings and become your fuel. I don't think dumping the clutch in 5th in a manual would work too well if you're out cruising. RPMs at that point would be high enough to pull through it.

92smokin blacky

I've heard a lot of guys that like the 4200 spring or have clipped their 3200 spring. Didn' BC847 dyno highest at like 3500 rpm with a clipped spring?
I've heard that the manual shut off won't even kill it which is why I'm wanting to put a valve in my intake.

jimbo486

Yeah, the only way to kill it when it's running away is to eliminate one of the 3 ingredients required for combustion... AIR! There may be a chance you could catch it early and use the manual shut off but I think you're reaction wouldn't be quick enough.

My pump will increase RPMs seemingly on it's own too. It's only because the governor flyweights are having to overcome a higher tension from the 3200 spring and therefore take longer to operate as they should. I have to be very light on the pedal in order to hold it at any given RPM above 2000 which is where my RPMs will increase on their own. Turning my starwheel up about 3 or 4 turns above stock seemed to calm it down quite a bit. I don't know how it did that just by increasing AFC spring tension but it did. I've only put 2 turns on my fuel screw too but, as you know, every pump is different.

mhuppertz

I don't have the fuel pressure for anything above 3k. The last 1/4 of my throttle travel does not add power, and I know it's fuel because it isn't smoking at that speed. Are you running a basically stock pump? I think it takes a 14mm head for 4k.

archer39

I agree, the VE stock does not deliver much fuel above 3k. Anything much above that is just noise.