This is topic MAP sensor? in forum Tech Talk at Northern California Ford Owners  .


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Posted by cheap (Member # 858) on :
 
Where is / what replaces the MAP sensor on 94s and 95s? My 92 computer on my 93 engine is pulling a MAP out of range fault code because I have no where (that I can see) to plug in the MAP on my 95 harness!!


Jeysus I'm running a bastardized operation here... but I still need help. All I can even find on the 93's schematics is the Barometric pressure sensor, not the MAP sensor, so I can't even figure out where the wires go.
 
Posted by PurpleNotch (Member # 2902) on :
 
Hey bro isnt the map sensor the one on top of the mass air meter? not sure though thats the only sensor that i couldnt find a name for. good luck ,Shaun [patriot]
 
Posted by Black94 5.0 (Member # 655) on :
 
Ok, a MAP sensor(manifold absolute pressure) is a sensor that works off a VACUUM line from the intake manifold...MAP sensors are used on mass air vehicles

A BAP sensor (barometric absolute pressure) is a sensor that reads atmospheric pressure and requires NO VACUUM line...BAP sensors are used on speed density vehicles..

On my '94 I have no visable MAP sensor... I have only one vacuum line comming off my intake and thats only for my power brake booster(PCV and charcoal canister is capped off)...The vacuum line that goes to my power brake booster "tree's" off and splits three ways...1 goes straight to the power brake unit..1 goes to the A/C and the other goes into my drivers fender and reads "S/C"...I'm not sure what the "S/C" vacuum line is for and what "S/C" stands for...

I this info helps a little...
 
Posted by FasterDamnit (Member # 442) on :
 
Umm, think you might be backwards. Manifold pressure for SD and Barometric for MAF. My BAP in my '92 is on the firewall w/ no hoses attached- just monitoring ambient atmosphere. If you have a mas air sensor- no need to measure the manifold pressure to calculate air mass being ingested. I think....
 
Posted by mike g (Member # 2919) on :
 
yeah your right faster...black got it backwards =P

mike
 
Posted by Black94 5.0 (Member # 655) on :
 
FasterDamnit~You're right...I guess I was thinkin too fast [dance] ...Man I only had 1 bottle of Guiness too!

Speed density will have the MAP with the vacuum connected...

Mass air systems will have the MAP sensor vacuum line disconnected, thus making it a BAP...

Thanx for straightin me out.. [Wink]
 
Posted by FasterDamnit (Member # 442) on :
 
It's hell getting old, eh? Remeber the days of having a six pack just to get primed for going out?

So, does any of this help answer the original problem?
 
Posted by cheap (Member # 858) on :
 
Yes and No... I came to about the same conclusions but didn't know I had a Baro sensor instead of a MAP. Here's a new question then: Why does my 92's computer pull a code for my MAP/BARO sensor out of range when the 94-95s don't use the sensor in the first place, but no one seems to have problems with the 93's A9L computers? What makes my computer different from an A9L, and is there some way I can splice in the Baro sensor into the 95 harness to make the computer shut up and run in normal mode?

Since my check engine light is on my car is running in safe mode, and Im getting about 6 miles per gallon.

[ July 31, 2003, 05:13 AM: Message edited by: cheap ]
 
Posted by cheap (Member # 858) on :
 
Ok after doing more research I found that the 94/95s don't even use the pin that would be BAP sensor, pin 45. Could I wire one in myself? And again, why does this problem not present itself when people install an A9L on SN-95s?

[Confused]
 
Posted by FMOS Racing (Member # 306) on :
 
Grab the plug and a length of wire out a pre-'94 mass air Ford at a pick-n-pull. Wiring it in isn't a problem. I don't have a diagram here with me, but there should be 3 wires on the sensor plug - a ground, a 5 volt VREF, and the signal out. The signal out will go to the EEC. You can tap the 5V VREF and ground at the EEC for the other two leads as well. Just stick the sensor anywhere.
 
Posted by cheap (Member # 858) on :
 
That's what I was thinking... the signal out goes to pin 45 in the EEC. Im just suprised that I've never heard of this before for 94-95 GT people that are using A9L EECs.
 
Posted by st5150 (Member # 51) on :
 
If this car won't do a lot of traveling, and you're getting a custom chip, you can just shut that sensor off.... its not a critical sensor unless you drive in different altitudes.
 
Posted by cheap (Member # 858) on :
 
ah, ok. Good to know, thanks sawson.
 
Posted by 5.0#4 87 T-Top GT (Member # 1534) on :
 
For you information
86-87cal 88 fed cars have map sensor
89-93 have baro sensor no vacuum
94-95 calculate the baro reading with the maf sensor there is no actual sensor for it, its all calculated through the pcm. to check if a maf sensor on a 94-95 check the baro data and if its off then the maf sensor is bad.
 




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