vacuum brakes

[NeilBlanchard]

Hello,

Originally Posted by bryn

i could idle in a lower gear but its a 3.8 liter engine lots of gas just to do that

On a lot of cars, downshifting shuts off the fuel to the engine.

[MetroMPG]

If you're forced to ride the brakes to keep your speed in check, I'd be inclined (pun intended!) to see whether or not you're within the engine's fuel cut-off zone first.

I've seen vac tanks added to EVs - they don't have to be as giant as a propane tank. People have used DIY sections of capped PVC pipe plumbed into the system.

Lastly, bryn, you should add your car to the garage so we know what you're talking about (it'll appear under your username in every post): Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

[bryn]

any way to check if fuel is shut off? or maybe I should just add a manual switch for the fuel pump?

[ttoyoda]

any way to check if fuel is shut off? or maybe I should just add a manual switch for the fuel pump?

This is for a manual transmission, I have not driven auto for 22 years so...
While coasting downhill, turn the key off, (your steering wheel will be locked so Danger, Will Robinson), was there a change? Turn ignition on (only to run, no starter motor, I am ass-u-ming the engine restarts from the auto trans drag). Was there a change? If you sense a change, the injectors were on during normal downhill coasting. In my cars, they are on. I would suggest turning off ignition with a switch rather than fuel pump, because that way you will not have the delay of re-pressureizing the fuel system on restart.

I've seen vac tanks added to EVs - they don't have to be as giant as a propane tank. People have used DIY sections of capped PVC pipe plumbed into the system.

I agree with you about the size, I happen to have a lot of propane tanks around, and I made a tool to remove the valve, plus they are already threaded, they are free, etc. So whenever some one says "tank" I always think propane tank.