Am i going to need it?

[kkchevy3]

im currently in the middle of a 4.6 stroker build for my 91 wrangler. My question is do you think im going to need a MAP adjuster? Im going with the 24# injector also. Secondly if i wanted to do an A/F ratio gauge to aid in tuning the MAP what would i need. Can i use the O2 sensor thats in the jeep now or do i need a different one.

[SilverXJ]

I can't give you a definite answer on the map sensor mod..

for an AFR gauge you can't use a the stock sensor as it is a narrow band and won't give you any info that is useful. I would recommend an AFR setup with data logging. That way you could find a nice open stretch of road, preferably one with an incline, hit the gas and then pay attention to the road and not the gauge.. later go back and pull the data off and see what you need to do.

[PolloLoco]

Can the stock sensor be replaced with a wide band sensor? I have OBD II software for my laptop which can do the data logging and pull the O2 sensor data from OBD II, along with RPM and speed.

[SilverXJ]

You can replace the stock O2sensor with a wideband sensor, however the PCM will not be able to use the wide band data, so the wideband controller will need to have an analog output for the narrow band. So no, you can't plug a wideband into the vehicle harness and have the PCM work with it.

[Muad'Dib]

Couldnt you just weld in another bung and have the wideband o2 in place permanantly?

[yuppiexj]

Couldnt you just weld in another bung and have the wideband o2 in place permanantly?

I forget that not everyone on this board has a welder/friend with a welder. Some of us don't even have a garage with which to work on our Jeep in.
I fall into this trap sometimes as well.

[Muad'Dib]

I dont have a welder, nor do i even have friends ... but how much could it really cost for a shop to do it for you???

[kkchevy3]

can anyone answer the question of the map adjuster? should i just build one and if the motor runs bad throw it on and see if it helps? Also with the homemade one, could i run the dial to control the map into the cab somewhere? And whats a wideban o2 sensor and gauge run?

[Muad'Dib]

Your probably going to need the map adjuster... even if only to fine tune it a little better. I personally would try it all without and then see what happens. If you feel it needs some fine tuning, build your own map adjuster and give it a shot.

[SilverXJ]

The problem is that if you have issues under WOT you don't tell that much from just the way it runs. You can burn valves with out pinging or wash the cylinder walls, depending on which way it goes. I got my wideband setup for $300 IIRC, sensor and gauge with data logging.

[laxplayermjd]

i know nothing about setting up an air fuel meter. I would like to set one up in my xj, but i do not need data logging, Could you just get a gauge and a wide band sensor? Could you recommend one? $300 almost what i paid for my jeep lol. Sorry dont want to hijack.

[gradon]

I recommend innovate's lc-1 wideband o2 and you can pick and choose your gauge(analog, digital, colors, etc)--should be less than $200 shipped on ebay. I bought the lm-2 w/ datalogging for $360 shipped. Innovates do have narrowband outputs as well so you can totally remove the upstream o2 and use that location for the wideband o2 and tap into the 12v heater circuit and the output that goes back to the pcm(I'd unplug an old o2 from the JY, cut off the sensor and use the tails to connect the Innovate). Anyhow, you really need the wideband to determine which way you need to tweak the adjustable map. I suppose if you were hearing pinging at WOT that you could up the voltage until you no longer heard it w/o seeing the afrs that a wideband would provide. You could also use a scanner to view the fuel trims and get an idea if you need to add fuel or pull it out(-trims mean pcm is pulling fuel out, +trims mean pcm is adding fuel). What BMW(s) do you have(or had)?