wannadiesel

Pastor- I have noticed that the engine feels "peppier" at light throttle since the lift pump upgrade. My theory on it is that the increased input pressure is causing the timing advance mechanism to start moving earlier. Does that make sense or am I all wet?

Rockjeep- I went to the nearest Cummins distributor (an hour away) and ordered the parts - which they had to ship.

Alec- The fuel line is different mainly because the pump outlet points towards the tappet cover at a 45 degree angle. After seeing first hand how tight it is in there, I think the line is worth the wait. I'll try to take some pics.

I think I am so... shall we say under-turbo'ed? that the extra fuel from the AFC was not helping power any, it was just making smoke and heat. It really doesn't feel any weaker on the top end, just a little "flat" in the midrange. edit: 3rd gear gives one that impression, but it's a whole different story at 80+ in 5th! See my later post. I definitely get more fuel with the AFC turned on, the smoke is black the whole time instead of clearing out.

It is nice to drive without one eye staring at the pyrometer. Now I can watch the tach instead.

mhuppertz

I'm dorking here, but what do you mean by turning the AFC on?

wannadiesel

The "valet switch" controls a solenoid valve in between the manifold and the AFC housing. If the switch is off, the AFC does not see any boost, so you do not get any extra fuel from it. Because I have a ground AFC lever, the truck is still pretty strong without that extra fuel. When I take pics of the pump I'll take pics of the new AFC plumbing.

mhuppertz

Cool, I'd like to see that. Makes sense. Do you still advocate grinding that AFC tang off, cause it's still on my list of things to do!

wannadiesel

Yeah, it makes a lot of power! I got to spend a good bit of time at extra-legal speeds today convoying to and from a dyno day/BBQ and I gotta retract my statement about the truck not feeling much different. It's a dog over 80 mph without the extra AFC fuel. Come out of valet mode and the beast comes alive! And the EGT monster is chasing it...

92DIESEL

can you say extra drugs

G1625S

''can you say extra drugs?''


Man, that rig is just a headin for rehab

g

wannadiesel

For Alec:

Shot of the pump:



A view of how close the line comes to the tappet cover:

wannadiesel

For Mark:

Air solenoid:



Connections at the engine and AFC housing:

G1625S

Dave, how do you have your fuel cone set? I was looking at my spare today and noticed, among other things, that the shallow side is also the 'leanest' side when no boost is present...in other words, the eccentric shape continues to the base of the cone. Meaning (I think) if you turned the cone to the shallow side and shut the AFC off, the base if the cone may limit the AFC pin more than if it were rotated to the deep side. Did that make any sense? If that's holds any water at all, a custom cut pin that was as wide as possible on the bottom (pushing the pin back as far as possible) with a steep ramp to allow max pin travel would be just the ticket.

g

swank

looking good, dave, looking good. did you put that valet switch together yourself? or was it a kit? seems like it looks an awful lot like something out of the grainger catalog.....

wannadiesel

My pin is a stocker that was "custom cut" before I got the truck. It's set deep - way deep.

Greg, that's a good idea. If I wanted to detune the truck more I could do that. I'm pretty happy with the in-town performance, once I hit 10 psi it cleans up pretty nice and the power is fine in the lower gears. A full custom pin would be the ultimate though. The aftermarket pins I'm aware of are set up to bring the fuel on as quickly as possible for better spool-up, but those of us with ground AFC levers need a different profile like you are describing. I would want it set up to bring the extra fuel on as late as possible. The "hard" part about a home grown pin is that the material needs to be so hard that you can't turn it down or cut the threads with conventional tools.

wannadiesel

Thanks Dave. You could probably get the solenoid valve from Grainger or someplace like that. It's a Humphrey 4-way, a 3 way would have worked but they had a 4 way in stock. It handles 150 psi, only consumes 4.5 watts, and has an exhaust port so boost can't be trapped in the AFC. It's really a way better solenoid valve than is needed. You could use an air horn solenoid and drill a bleed hole in one of the fittings on the AFC side.

SteamDave's buddy Adam picked up the parts from a trailer builder he knows.

Monty

I have been holding off on the piston pump. More or less because of the inlet pressure. As frostie said, we have always heard that over 15 and your in danger of knocking out seals.

Alec

Boy that pump outlet is tight in there. Can you even get the pump on (forgetting the fuel line) without cutting off the sound cover?

That valet switch install looks great over on the water meth controller bracket.

Where did that information on the pump seals come from originally? (Remember, a VE pump can't produce over 300hp . . . )