Topic: Map Adjuster Voltage

[chrisfranklin]

For you guys that have built your own or are using the Turbo City or some other version of adjustable MAP, what voltage do you have your set to for best performance for the modifications you have?

[chrisfranklin]

Alright, I'll fess up -- the Turbo City Adjustable MAP I ordered showed up on my door step today.  I know, it's $140 and you can do just as well building your own for $20.  But I figured that I'd have enough to think about getting it set up correctly, let alone making sure I put the thing together correctly from Radio Shack parts. 

So, I went Turbo City and it looks like a pretty sturdy unit that includes install directions and how to restore it to stock without removing it. 

Of course, now we get in to Voltage and A/F ratios.  I've got a grand total of 3/4 of a turn with the adjustable MAP screw voltage adjuster on the unit.  I do have a voltmeter at least. 

But without an A/F wideband sensor, I'm guessing at what voltage adjustments will yield in terms of A/F ratio.  Since I can reset the thing to stock whenever I want, I'm mainly asking around for what voltage numbers have thus far yielded the best sop performance and not worrying so much about the A/F ratio that these numbers would tend to represent. 

So, if you have one of these adjustable MAPs, please tip me off as to what Voltage you are running yours at.  Thanks!

[Jeffy]

I would monitor the voltage from the stock setup then work from there.  No 2 MAP's are exactly the same as some have higher thresholds then others.

[chrisfranklin]

Reading the instructions again, it looks like you are advised to increase the voltage by .2 from whatever your stock voltage reads -- stock is said to typically read 4.6-4.85 volts.  So, I'll have to see what voltage I start off with. 

[sharpxmen]

Reading the instructions again, it looks like you are advised to increase the voltage by .2 from whatever your stock voltage reads -- stock is said to typically read 4.6-4.85 volts.  So, I'll have to see what voltage I start off with. 

you modify your supply voltage which is 5v for stock, so start by measuring your new voltage regulator supply first.

[chrisfranklin]

I got going on installing this adjustable MAP today and took a few photos I'll dig up later.  Good news for YJs is that this Turbo City setup just plugs right in between the existing plug and sensor -- TJs need to do a little cutting and splicing but the extra plugs needed for that are included.  

Bad news for me has been getting before and after voltages -- actually really just "before" voltage, though I am probably going to have the same problem getting an after.  Directions advise you to keep the MAP sensor connected, then stick a paperclip up in the the rubber cap of the middle wire on the green plug and make contact with the metal plug or exposed wiring. Then get out your voltmeter and connect the positive end on the paperclip to the map sensor plug, and ground the negative cable.  With the keys in the ignition and turned to get the accessories going, you then should be able to get a stock voltage reading for your MAP sensor.  

So far I'm not getting anything -- maybe I'm not getting contact with the paperclip.  I can just strip some of the rubber off the middle wiring harness and probably get a reading that way instead; taking a lunch break

 

[sharpxmen]

I got going on installing this adjustable MAP today and took a few photos I'll dig up later.  Good news for YJs is that this Turbo City setup just plugs right in between the existing plug and sensor -- TJs need to do a little cutting and splicing but the extra plugs needed for that are included.  

Bad news for me has been getting before and after voltages -- actually really just "before" voltage, though I am probably going to have the same problem getting an after.  Directions advise you to keep the MAP sensor connected, then stick a paperclip up in the the rubber cap of the middle wire on the green plug and make contact with the metal plug or exposed wiring. Then get out your voltmeter and connect the positive end on the paperclip to the map sensor plug, and ground the negative cable.  With the keys in the ignition and turned to get the accessories going, you then should be able to get a stock voltage reading for your MAP sensor.  

So far I'm not getting anything -- maybe I'm not getting contact with the paperclip.  I can just strip some of the rubber off the middle wiring harness and probably get a reading that way instead; taking a lunch break

 

you can take out the rubber seal so that way you'd have the end of the pins exposed. I suggest measuring the supply before connecting the map adjuster to make sure is not too high.

[sharpxmen]

how did the install go?

[chrisfranklin]

I didn't get a chance to go round two with it today.  Hopefully will get in there to work on it tonight or tomorrow night.

[chrisfranklin]

I've got a couple of things holding me up on putting this Turbo City Adjustable MAP in

- Getting the initial Voltage reading turned out to be a little more trouble than I expected the other day.  Given the hour I spent on Saturday fishing around with the paperclip in the MAP, then pulling apart the Turbo City connectors I didn't need to examine their construction and where the clip would be making contact, I'm still kind of surprised my voltmeter didn't get a reading.  I figured I'd at least get a jump in readings numbers as the clip connected briefly when I tried different positions.  I thought it might have been the meter or its settings, so I tried it on the 12V battery and an AA cell, but it worked fine. Had the ignition key on, but engine not started.  I'll pull out the rubber seal on the MAP wire and give that a go or maybe just expose a little of the wiring and get the voltage that way.  But I'm still thinking maybe the MAP isn't getting power for some reason  -- maybe key position is wrong.

- I'm also supposed to "Connect white wire of Map Modifier to +12VDC Key On Wire using multi-lock connector."  The adustable MAP (aka "Map Modifier") does have a long white wire.  I was digging around my Chilton's manual to identify where this 12VDC Key On Wire  exactly was in the engine bay and then go from there.  Of course Chilton's is leaving me hanging.

I'll get all this eventually digging around.  But if you have any tips, please help me save some time   Trying to get a photos of everything

[sharpxmen]

i'll dig in my notes tonight and tell you what wire to use for 12v switched (i had some wires listed in an excel spreadsheet when i connected the Split Second for my s/c setup, had the same problem and took 2 tries to get it right).

[sharpxmen]

i'll dig in my notes tonight and tell you what wire to use for 12v switched (i had some wires listed in an excel spreadsheet when i connected the Split Second for my s/c setup, had the same problem and took 2 tries to get it right).

white/yellow wire going to the PCM pin 9 is key switched +12v

[chrisfranklin]

The PCM for the 92-95s is located in the engine bay, right?  I personally haven't messed with it before.  Is it behind the window washing fluid or is it on the other side near the battery and fuse box.  Don't have my Jeep nearby unfortunately.  Appreciate the tip on the pin #9 wire Sharp.   

[sharpxmen]

The PCM for the 92-95s is located in the engine bay, right?  I personally haven't messed with it before.  Is it behind the window washing fluid or is it on the other side near the battery and fuse box.  Don't have my Jeep nearby unfortunately.  Appreciate the tip on the pin #9 wire Sharp.   

you don't need to get to the PCM, just to the bundle of wires going to it. but yes, it is in front of the washer fluid bottle on the firewall, forget about pin 9, i just listed as it was in my spreadsheet, the white/yellow wire is the one you want, make sure you solder it if you cut it and use shrink tube on it.

[chrisfranklin]

Alright I'll find the white/yellow wire in the bundle to the PCM.