• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Adj. MAP Mod on a newer XJ?

JeepinAudiophile

JeepinAudiophile

NAXJA Forum User
Location
Northborough, Massachusetts
I have a 2000, where the sensor for the map is located directly on the throttle body- instead of on the firewall as they were previously. I made the map adjuster the other day because i was bored figuring that if it didn't work with my jeep, i just made someone else's life a bit easier. The wires are different colors, when un-plugged from the throttle body-two of them read 5v..(one is 5.13v, the other is 4.97v) Is tyhis the same as the others? I would imagine it is the same thing, just in a different place- but they made so many other changes so who knows.. I plan on doing some more testing when i get a chance. But if anyone knows the info, this would save me a lot of time and aggravation. If anyone knows that it will not work, i'm putting pics of the adj. map here in case anyone wants to buy it. (will be back to edit in with photos after i take them)
 
btt, i've got a 96 and its on the tb too

I heard that odbII may not like this mod?!?
 
Just be forewarned.... IF you are running an aftermarket performance computer chip (ie. JET, SuperChip etc...) then dont do this modification.
The aftermarket computer chips modify air/fuel ratios and timing. By adding the MAP adjuster you are modifying again what the computer chip has already done.....
Almost 6 years ago..... I made this mistake and my 98 lost power, mpg and idled terribly..... Lesson learned.......

Charles
 
thanx for the info... i don't have a chip... that will come next if I can't use this mod. Oh yeah, and here's the pictures...
5557PICT0445-med.JPG

5557PICT0449-med.JPG

5557PICT0446-med.JPG
 
keep us posted im might be interesed in this too , for my 2kxj. dr dynowill probbley have a good idea on this too ,if he see the thread.
 
Update:
I installed the adj. map mod using the green wire with red trace, being the 5v input on the sensor. I gained 1 mpg over my 40 mile drive to work from yesterday, driving exactly the 0same. This is an applicable mod for the xjs with sensor on the tb... I will get back woith more info as i test and dial-in.
 
WooHoo!! what a difference over stock... this really makes my previous mods come to life!
 
so, you think you could build me a controller like that? Is there a thread where I could build my own.

-rusty
 
There are lots of companies that make MAP adjusters and if you do a google search, you will find both the plans with instructions as well as suppliers.
 
look at Dr. Dyno's web site he made one of these and i think he put instructions up on how to do it. J.A. where did you get your instructions from?
 
hmmmm.....improved mileage and performance
having my cake and eating it too
 
btw, what voltage have you dialed it too, and did you mount the box in the cab or engine bay
 
it's in the engine bay, i read dr.dynos how to, then the 2 links he has in there(http://www.angelfire.com/my/fan/MAP_adjuster.html)... they're all pretty much the same.... then i bought the parts, and made the design my own... i like my electronics nice and neat- that's what i do for a living right now, high end mobile electronics. I think i would like to pull the adj. map out and revise my design... i would like it switchable and adjustable from the cab. This however would be a new design, so anyone want mine when i build the new one sometime next week hopefully? It cost me more like $17 to make mine... anyone want to make a reasonable offer? Keep in mind that i may not even take it out, but i'll decide that sometime next week. Oh yeah, i'm running it about 5.6v for now, but im still testing. I started out at 5.9v, which ran GREAT at low rpms, great power, etc... but if i put my foot down to shift gears and accelerate, it would jump erratically and not accelerate... flooding. I'm still playing around though- hoping that i can get a real means to test it sometime soon.
 
I built one for my 2.5 yj.... with the 4.0L t-body, 2.5 full exhaust, msd and jacobs, and other tweaks, it really helped it run good. I built it from spare parts, not hard at all if you know electronics. Im not sure how much good it would do on a stock or lightly modded engine.....
 
I thought an adj. MAP wasn't suppose to work on the OBDII vehicles?
 
CharlesS said:
Just be forewarned.... IF you are running an aftermarket performance computer chip (ie. JET, SuperChip etc...) then dont do this modification.
The aftermarket computer chips modify air/fuel ratios and timing. By adding the MAP adjuster you are modifying again what the computer chip has already done.....
Almost 6 years ago..... I made this mistake and my 98 lost power, mpg and idled terribly..... Lesson learned.......

Charles
Click to expand...

I'm running my own MAP adjuster AND a JET Stage 2 with no problems at all. Then again, my computer's OBD I. The OBD II is smarter and probably not as easily fooled by a MAP adjuster.
________________________________________________________________________
1992 XJ Laredo 4-dr - 4.6L I6 HO Stroker - 176k miles - AX15, NP231, D35c, D30
Estimated 263hp/323lbft, best 1/4 mile [email protected] before stroker install
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks
 
Well, it definately makes a difference... i can change the fuel ratio..... I made another mod and testing has since been restarted... and i started driving like a Mass-Hole again so the numbers are shot... i had my exhaust cut off from tyhe muffler back, they welded on flanges and made me an identical piece out of 2" stainless that also bolts on... i got back a lot of low end torque...but lost the high end power... just as i expected to... i want to figure out a middle ground... i found out that i may have access to a dyno for free, so i wanted to be able to bolt either on to test the differences of the two on the dyno graph... So, that's where testing has began again, now i just need to stop doing 90 mph on the highway here, and go back to my 67-70 mph in order to get testing back on track.

I have been so busy with opening the new shop that i have not had any time to sign on, sorry it took me so long to respond...
 
Any updates on this, I have a 2001 and am about to build one myself. Please anyone with the newer XJ's offer your experiences.

I know this is an old thread, but there isn't a whole lot on here for MAP adjusters for 97+.
 
You must log in or register to reply here.

Similar threads

F
Curious MAP sensor failing - symptoms
Replies
0
Views
2K
fenns7
F
D
Specific Moab Wheel On XJ
Replies
16
Views
234
DirtySouthXJ
D
Jeep70
96 XJ Transmission issues
Replies
3
Views
58
RCP Phx
R
D
XJ Rear Hatch Lift Or Power Glass?
Replies
11
Views
151
Veeb0rg
Veeb0rg
D
Durango master cylinder? Booster? (2000 XJ)
Replies
6
Views
1K
89Mock
89Mock
Back
Top