New Guy with a 1989 Ford Escort

[jmedia]

Thanks for everything so far guys, I thought i knew engines but I'm used to an AMC 360 where everything is right in front of you.
I guess I'll have to search to find a way to do it without vss(<=what is that?)

I was wondering if anyone could quickly explain the vacuum system in a vehicle. I believe I understand it somewhat but not sure. And why is it good to have high pressure in the vac lines for mpg?

Thanks again!

[Ford Man]

VSS is short for vehicle speed sensor. The reason you want high vacuum is because more load on the engine means lower mileage and the more load that's on the engine the more your vacuum drops (wider throttle opening). Wide open throttle will mean very low engine vacuum probably 0 inches or very close. Cruising at 55 mph under low load you'll likely see 12-15 inches of vacuum. At idle you'll probably see about 20 inches of vacuum and on deceleration with engine braking probably 22-25 inches of vacuum. This probably isn't the scientific explanation, but anyway you get the picture.

[wagonman76]

Originally Posted by moorecomp

If your car is fitted with a cruise control, it has one of these on the speedo cable and maybe the signal from it could be used for the MPGuino. Maybe could even fit it even if you don't have a cruise control.


Motorcraft OEM DY-416 DY416 Acceleration Sensor 84-95 - Less than $30

My old Celebrity wagon with a cable driven speedo had something similar on the speedo cable to feed pulses to the cruise and ECM.