Adjustable MAP Sensor

Ok, so I know what a Adj. MAP sensor is, what it does, and how it works, but when should I use use it? Should I use it? How do I know it's adjusted correctly?

do you have a stroked motor?
a super or turbo charger?
if not, then you dont need one, so no need to worry about the settings....
if you do have any of the above, get to doing some heavy homework regards fuel/air mixtures.

martin

I live at 6500 feet above sea level and drive up and over the passes(8,000 feet) on a regular basis. 4.0 auto, Dynomax catback, throttle body spacer, air-tube w/ K&N filter.

Cant you tune your A/F Ratio with one? Meaning you could lean it out a little and get a touch higher gas mileage, or dump in a little more fuel and get a touch better performance over stock numbers? I read somewhere how to make your own adjuster and it showed ratio numbers and what they would do but I just want to confirm this info

Baja_XJ said:

Cant you tune your A/F Ratio with one? Meaning you could lean it out a little and get a touch higher gas mileage, or dump in a little more fuel and get a touch better performance over stock numbers? I read somewhere how to make your own adjuster and it showed ratio numbers and what they would do but I just want to confirm this info

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You could try using the high altitude CPS/CKP for a little advance to your timing, a**uming you still have the Renix in your profile.

The FI system already runs a little on the lean side. Most of the use of the adj. map is to get a little more power. You can do the same thing a lot simpler by installing a lower temp thermostat in the engine.

You can't really use a setting chart to fool with your A/F ratios. You need to know what's happening in your engine, not somebody elses' guess. To accurately use any adjustable system(map, temp, O2, whatever) you need to install a wide band O2 sensor ahead of the cat, wired into a readout on the dash. Also, if you're trying for max fuel economy, you should also have an exhaust gas temp. gauge.

I already have a 170 thermo, I wasnt wanting to lean it anymore, I was going to pump it up and give it a decent amount of fuel. This is the place Im referring to: http://www.go.jeep-xj.info/HowtoMAPsensor.htm

move your air temp sensor from your intake manifold to your air box or air tube

Baja_XJ said:

I already have a 170 thermo, I wasnt wanting to lean it anymore, I was going to pump it up and give it a decent amount of fuel. This is the place Im referring to: http://www.go.jeep-xj.info/HowtoMAPsensor.htm

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Running a 170 thermostat could lead the ECU to running in open loop all the time, this would make the fuel mixture rich, not lean.

old_man said:

Running a 170 thermostat could lead the ECU to running in open loop all the time, this would make the fuel mixture rich, not lean.

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Exactly. Also increases the wear rate on the engine.