Bizarro fuel-economy results...

[Archangel]

The smog pump provides more vacuum for the cruise, so you might want to put that back on.

Wait, what? That thing is an air pump, not a vacuum, how does it make vacuum for the cruise? And FWIW, the vacuum pump in my truck is damn near dead, I need to hit at least 1500 rpms for it to make enough vacuum to work my HVAC stuff, and it only works the those and the cruise, nothing else - still my cruise works absolutely perfect, if anything the high vacuum the pump supplied when it worked good was causing it to slowly increase cruise speed, we're talking about 2 mph after over an hour of driving so nothing too bad, but it was definitely there...

[Glen]

I get 20 - 21 mix city and highway.

[Archangel]

that sounds about right, for a 50/50 mix of driving environment. I've seen as good as 28 mpg a few times (perfect weather, looong road, cruise at 55, no hills), 26 more common, 24 average freeway at like 70-75 mph.

[86VickyLX]

Wait, what? That thing is an air pump, not a vacuum, how does it make vacuum for the cruise? And FWIW, the vacuum pump in my truck is damn near dead, I need to hit at least 1500 rpms for it to make enough vacuum to work my HVAC stuff, and it only works the those and the cruise, nothing else - still my cruise works absolutely perfect, if anything the high vacuum the pump supplied when it worked good was causing it to slowly increase cruise speed, we're talking about 2 mph after over an hour of driving so nothing too bad, but it was definitely there...

It creates a venturi effect inside of the pump. Ever wonder why there were two little hose fittings on the pump? One of them gets attached to a hose goes to the cruise, the other just sits there open, and it makes like a farting noise. That one shoots out air, while the one connected to the hose sucks air.

[gadget73]

It creates a venturi effect inside of the pump. Ever wonder why there were two little hose fittings on the pump? One of them gets attached to a hose goes to the cruise, the other just sits there open, and it makes like a farting noise. That one shoots out air, while the one connected to the hose sucks air.

Yup.

Normally it can be removed without any effect, but I dont know what will happen if the vacuum hose is still plugged into it and the smog pump isn't running. Its got a one-way valve that in theory ought to prevent any problems, but if the check valve leaks, all bets are off. I have none of that crap on my car, and the check valves are all removed. Cruise works great.

[import convert]

with my car due for an oil change i got 14mpg average though i bet i could do better if my choke idle wanst so high and i didnt like to step on the throttle. course i think the 2.73 gear hurts me on the highway going up hills (always shifts to 3rd)

[Cyberats]

My 1991 MGM gets 14mpg city and recently 22mpg hwy. at 65mph and 23mpg hwy. at 60mph. 91 octane only. So the peak mpg curve does top off at 55mph for this setup.

[donaldderby]

I know unknown fuel additives are taboo pretty much any where but i am young and dumb so i used to do 3 oz pure acetone (not nail poilish romover) to every 10 gallons of gas +/- 1/2 oz and averaged 32mpg on a trip home from camp lejeune to mass with speeds varying from 55 - 65 with a couple spurts to 100+ (cross bronx express way) any ways just my . Now lets see howmany try and raise the
p.s.
keep in mind i use amsoil in the crankcase transmission and rear differental.

[Archangel]

It creates a venturi effect inside of the pump. Ever wonder why there were two little hose fittings on the pump? One of them gets attached to a hose goes to the cruise, the other just sits there open, and it makes like a farting noise. That one shoots out air, while the one connected to the hose sucks air.

Ah, yes, forgot about those things, I only had the pump in mine for just a bit, then it was gone for good! lol

Normally it can be removed without any effect, but I dont know what will happen if the vacuum hose is still plugged into it and the smog pump isn't running. Its got a one-way valve that in theory ought to prevent any problems, but if the check valve leaks, all bets are off. I have none of that crap on my car, and the check valves are all removed. Cruise works great.

I actually double-stacked check valves for my HVAC stuff, there's one right off the tree and another one a few inches behind it, then there's a small vac canister (the one for the EVR in the Lincoln actually) in there to make sure I don't lose "prime" overnight. May throw in a larger one if I find a suitable one, and place to put it in, for its size this engine bay is pretty darn cluttered. Cruise, I don't think I have any valves in there, whatever is in the reserve canister head, but just that. Seems to work good, but IIRC there's a least one 1/4" check valve floating in my box of vacuum stuff so I may dig it out tomorrow and throw it on as a good measure.

[gadget73]

The soup can is actually for the climate control. There is a check valve for that right on the firewall vac manifold where the vacuum line goes into the car. I have that one. The T shaped one I removed. I think there may be a one-way between the vacuum manifold and the cruise servo that I used to connect the lines together, but I'm not sure. It all works fine, so I don't mess with it.

[Archangel]

My soup can is for the cruise, as far as I see - there's only two hoses going through the firewall, the fat one is for the cruise vacuum dump switch at the brake pedal, and the second one is tiny and disappears in the heater core box. I put my second vacuum canister so that the small hose sucks off it, it seems to have helped the HVAC.

[1987cp]

p.s.
keep in mind i use amsoil in the crankcase transmission and rear differental.

You can buy several gallons of extra gas for the price of all that Amsoil ....

[gadget73]

My soup can is for the cruise, as far as I see - there's only two hoses going through the firewall, the fat one is for the cruise vacuum dump switch at the brake pedal, and the second one is tiny and disappears in the heater core box. I put my second vacuum canister so that the small hose sucks off it, it seems to have helped the HVAC.

the way the soup can is supposed to be plumbed, on the firewall there is a one-way check valve with 2 outlets on it. one outlet goes to one of the small hoses that vanishes through center of the firewall, the other goes to the soup can. The vac dump valve feed goes through the firewall closer to the brake pedal. Also there should be 4 hoses through the firewall, 3 near the vac manifold, one is the vac source to the hvac stuff, and the other two go to the thermal blower lockout switch. The other is the larger dump valve line.

[Archangel]

Thain, I was talking about the dually, the Townie gots all sorts of vacuum lines, freakin nightmare. The blower lockout on that one is bypassed, wires are spliced together and the vacuum lines are plugged cause the darn thing never worked right.

[gadget73]

The blower lockout on that one is bypassed, wires are spliced together and the vacuum lines are plugged cause the darn thing never worked right.

Same. Only time I had one in there it caused problems, then exploded and caused me to overheat the car like a week after i installed it. it went in the trash.