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usergone · 02-20-2011, 10:31 PM

The title may seem like a "been there, done that" thread, but hear (read) me out.

Just about any list of FE-improving driving techniques will tell you to keep your foot out of it as much as possible. More throttle = more power out = more fuel in.

To avoid confusion, let me mention right now that I have a diesel.

On my truck, I don't have a throttle pedal. I have a governor pedal. The injector pump compares the "target" engine speed (throttle position) to the actual engine speed, and injects more fuel if it needs to go faster and less fuel if it needs to go slower. This is nice because any time I am engine braking (above about 1000 rpm) it is in DFCO "mode." But that is beside the point.

The way that my injector pump is set up, there are multiple adjustments to the amount of fuel put in, but the most important one (for this thread) is the rack travel limiter. That is basically a full throttle stop for the fueling.

If I adjust that, it will limit me to a certain (consistent) small throttle position, and it is also impervious to the urge to floor it (because to "floor" it, I would have to take the cover off the IP again)

I have adjusted it to the minimum "throttle" travel possible, and the truck feels like it has about 1/3 the power of stock tuning. I will be filling up in the next few days and getting a feel for how the FE will respond. I suppose that, self control and overall interest permitting, I could even do some tanks ABA.

I am putting this in the "ecomodding central" subforum because it is a "mod" not a driving technique so much.

02-20-2011, 10:31 PM	#1 (permalink)
usergone I have to start over? Join Date: May 2010 Posts: 214 Big inefficient truck - '94 Dodge Ram 2500 90 day: 12.1 mpg (US) Honda Civic - '84 Honda Civic DX Hatchback Thanks: 2 Thanked 8 Times in 7 Posts	Small throttle positon for FE The title may seem like a "been there, done that" thread, but hear (read) me out. Just about any list of FE-improving driving techniques will tell you to keep your foot out of it as much as possible. More throttle = more power out = more fuel in. To avoid confusion, let me mention right now that I have a diesel. On my truck, I don't have a throttle pedal. I have a governor pedal. The injector pump compares the "target" engine speed (throttle position) to the actual engine speed, and injects more fuel if it needs to go faster and less fuel if it needs to go slower. This is nice because any time I am engine braking (above about 1000 rpm) it is in DFCO "mode." But that is beside the point. The way that my injector pump is set up, there are multiple adjustments to the amount of fuel put in, but the most important one (for this thread) is the rack travel limiter. That is basically a full throttle stop for the fueling. If I adjust that, it will limit me to a certain (consistent) small throttle position, and it is also impervious to the urge to floor it (because to "floor" it, I would have to take the cover off the IP again) I have adjusted it to the minimum "throttle" travel possible, and the truck feels like it has about 1/3 the power of stock tuning. I will be filling up in the next few days and getting a feel for how the FE will respond. I suppose that, self control and overall interest permitting, I could even do some tanks ABA. I am putting this in the "ecomodding central" subforum because it is a "mod" not a driving technique so much.