Map Sensor Adjusters

[Scottr]

The Leigh Performance Map Adjuster is so small. How do you adjust the voltage? Or is it preset?

Thanks,
Scott

[superstingray77]

I built and ran my own MAP adjuster on the WJ with the solid cammed stroker. My .02 is its a bad idea on the OBDII JTEC PCM. The difference a full on proper tune makes is huge as there are many areas that can and need to be re-worked for proper drivability,economy,total power across the entire RPM band. Granted my cam is large (.524/.542) and the factory program would freak out and pour in a TON of fuel at idle/midrange due to the low vacuum then lean out at the top. Backing off the MAP voltage to 4.1v would bring the idle/low speed into play but caused a SEVERE lean out by 3k. A patch job at best. Once tuned the engine ran and drove like a stock jeep (with a mean sounding idle) but otherwise got great mileage/power/and averaged 16 city/22+ freeway. Before the proper tune (505 or MAP adjuster) it would average about 12mpg no matter what and was likely making the same HP as a stock engine with more torque. For me it was simple if i spent all this money on building a nice engine its silly to save 500 bucks by not tuning it properly.

[darkcorp]

Has anyone tested those MAP enhancers from ebay? Will they work?

http://m.ebay.com/itm/MAP-MAF-SENSOR-EN ... Ciid%253A1

http://m.ebay.com/itm/HHO-Map-Enhancer- ... Ciid%253A5

[SkylinesSuck]

They look like adjustable resistors which is all map adjusters are, but they say "instructions sent with item" so their is no way to know for sure. As cheap as they are, order one and hook it up to a multimeter and find out.

[Gabriel]

I know this is an old thread. Does anyone have instructions for the Leigh Performance MAP adjuster? It no longer seems to be on line. I have one of his units and figured I would look up the instructions since the paper was not with the unit. It appears it is not on line any more. I was going to get my 4.5 on the Dino today but will have to reschedule.
Thanks
Lee the newbie

[aguiar_racer]

Anyone know where i can buy a mapsensor adjuster?

[SkylinesSuck]

I have an SAFC2 if you aren't afraid of a little splicing. Not hard and much better.

[Cummins90]

Aem FIC will work as a map adjuster along with a handful of other features. If you want to wire it into a JTEC pcm an extension harness will be available in the near future so you dont need to hack apart your stock harness.

[Sean295]

Question on these...I built my own...Have a switch so I can run the stock and flick the switch for the adjuster...I set it to 5.13 volts.... when i switch it on i get a high voltage map check engine light....is there anyway to avoid this? I'm not sure if because the check engine light comes on if that makes the computer bypass the sensor voltage and go with a preset number.

My motor is a stroked 4.6L with .035 quench and 24# injectors on my 97 tj....has distributor

[Cheromaniac]

I never had the Check Engine light when I had my MAP voltage set higher than normal. Perhaps the OBD II engine management system is more finicky than the OBD I.