Adjustable MAP sensor

Exxon Valdez Jeep

NAXJA Forum User

Location

Temple TX

• Dec 31, 2009

• #1

Dumb question, but I'll ask anyways. I have a stroker in my Renix xj, so therefore an adjustable MAP sensor would be desired. Is there any difference between and adjustable MAP sensor for a Renix system and a HO system? It seems like all the diagrams on building one are being used in a HO, am I missing something?

 

A

AJPulley

NAXJA Forum User

Location

South-eastern MA

• Dec 31, 2009

• #2

I built one for my Renix years ago and it works fine. I'll assume you understand the principal of what a MAP does, and how the ECM interprets its voltage output. The RENIX uses a typical 5 volt MAP sensor, so anything you build that regulates the voltage to be slightly higher relative to the adjuster's voltage input (sensor output) will accomplish the end result. It's an analog device, not digital, so any basic adjuster (which is really a regulator of an external 12 volts controlled by the sensor's output voltage) will do.

 

Last edited: Dec 31, 2009

Exxon Valdez Jeep

NAXJA Forum User

Location

Temple TX

• Dec 31, 2009

• #3

So either one of these should work fine?

http://www.go.jeep-xj.info/HowtoMAPsensor.htm

http://www.angelfire.com/my/fan/MAP_adjuster.html

 

A

AJTorris

NAXJA Forum User

Location

California

• Dec 31, 2009

• #4

Is there anywhere you could buy one already made up?

 

A

AJPulley

NAXJA Forum User

Location

South-eastern MA

• Dec 31, 2009

• #5

Yes, both are electrically the same. It is the same schematic I used.

Last I knew, years ago, Turbo City made one.

 

OkieXJ

NAXJA Forum User

NAXJA Member

Location

Muskogee, OK

• Jan 4, 2010

• #6

http://www.quadratec.com/products/17010_600.htm

I believe this is what you might be looking for. It might be worth the money if you've never messed with electronics and soldering before. I was looking for information on whether it is adjustable and if so, how to adjust it to the optimum level etc. Hope this helps.

 

A

AJPulley

NAXJA Forum User

Location

South-eastern MA

• Jan 5, 2010

• #7

That's the one. There is no definitive setting without using external instruments to measure the results of your combustion. Whether you build one or buy one, it is going to be an experimentation process, and your setting will vary from that of someone else, especially considering the variations in engine setups (fed/CA emissions, ECM model number, auto/man, air filters, filter housings, intake tubes, heads, cams, stroked engines, headers, etc.)

 

OkieXJ

NAXJA Forum User

NAXJA Member

Location

Muskogee, OK

• Jan 5, 2010

• #8

I guess all I need is a passenger and a multimeter to adjust the setting. If their values to shoot for at Wide Open Throttle for the O2 sensor (.850mV an .900mV) are correct, then it shouldn't be too hard to set. I've been looking at building one to help solve my gas mileage problem, but that article gives a great way to check my O2 sensor to see if I'm running in open loop mode. I'll make sure its running is closed loop mode as a first step.

 

A

AJPulley

NAXJA Forum User

Location

South-eastern MA

• Jan 6, 2010

• #9

As simplistic as the Renix system is, you have no control over whether or not it is in open or closed loop mode; that is, your only control is knowing when it's in open loop. That's the nature of how the processor works based on the inputs it receives.


Good luck.