Since my TBI uses the same MAP and it has the bracket that mounts it along the firewall can I just keep it located there and run a vacuum line to the plenum? Also The plenum now is from a MAF car so I need to tap into some type of vacuum, which line should I 'T' off? Or should I tap right into the plenum and what would I use if I do that?




Thanks

 

do not "T" that off. for a map sensor you want the line as short as possible,map sensor has to do with air/fuel mixture at WOT unlike o2 which helps dictate part throttle air/fuel. Map sensor hose size also can modify timing advance. Also mount the map sensor upright like it is stock, helps prevent moisture from getting in the lines and throwing off its readings.

 

Your tpi plenum should have a spot for the map sensor on it. If not let it hang with a short hose,just as long as it doesnt get moved around much

 

Only if it came off a MAP TPI engine
MAF plenums don't have the threaded hole for the MAP bracket or the 3rd vac port to connect to it


There are only 2 vac ports on the MAF plenum.
Use one only for the MAP sensor and T off the the other port for the fuel reg / EGR / HVAC controls

 

I ran into this problem and put a third vacuum fitting in the plenum (mine was from a MAF car). I tried "t-ing" the vacuum and always had something to not function properly. As for the sensor mount I reused the TBI location on the firwewall and ran a line to the port on the plenum and the car has never had any problems related to it.

 

If you relocate your MAT sensor thats under the plenum to someplace in the air intake, you could put a 90deg hose fitting in that port just for your map sensor.

 

I have a done couple of HSR setups with the MAP in similar position on the firewall and no probs

 

what kind of a vacuum fitting did you use and where did you put it?

 

I just used another GM fitting (not sure the size),drilled and tapped the hole in the area just behind the passenger side runner. Be careful to check the thickness of the material in this area, the first plenum I used had plenty but the second one that I ported and siamesed was thinner. Don't ask me why 2 plenums with the same p/n had this difference.

 

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