Hey guys,
I currently have my MAP sensor connected to the nipple on the LIM that faces the passenger side of engine bay. Is this the ideal place to get this tap from? I thought I read somewhere that it is too close to the ports and will get erratic readings which will affect idle. And I'm getting erratic idle. I tried connecting the MAP to the center nipple on the TB that faces the firewall but I got a 0 reading and the car started to run rich. I've blocked off all the other nipples from TB and using that one I tried for the blow off valve. It works for the blow off valve but not for the MAP sensor. Where should I tap for MAP sensor? Thanks in advance for the advice.

 

assuming you have a TII

connect to the bottom nipple

look at the pic
run your boost gauge and the fuel pressure regulator from the same source
via a splitter aswell

 

This view is looking at the TB when in front of car, right?
So just block off the top 2 nipples then? I think I have all 3 of those blocked off currently. I have the BOV tapping off the center nipple on the other side of TB, that seems to work fine.

 

I had researched this for my friend about a year ago when I installed a Microtech in his 91 TII. If I remember correctly, the nipples on the TB that are facing the firewall are for blowing air at the injector for better fuel atomization, and thus the reason that it reads "0". All of the nipples that are facing the front of the car are all vacuum sources, but each one gets vacuum from a different port setup: aka: secondary ports, primary ports, etc.
First and foremost, my advice is this: DO NOT USE A SPLITTER!! You need a DIRECT source for the MAP sensor and using a splitter "distorts" the signal. I found this out the hard way: my brother's widebody first gen (13B streetport, T04B turbo, Microtech, etc) got somewhat tuned at a dyno----ran pretty good!! Afterwards, the guy suggested that I fix the MAP sensor source because I used a splitter and it was making the car somewaht hard to tune. After I fixed it, the car ran much different and was running really rich----ran like ***!!!
Anyway, my friend gets his MAP source from the LIM-----no splitter!!
Just my .02

 

In other words: When I corrected the MAP source problem, it showed me how much of a difference it made when making the mistake of using a splitter!!

 

Well those Instructions came from Matt the HitMan

I have a FD upper manifold
and I have the MAP line Split going to the upper intake Manifold Flapper

The FD has 2 butterfly assemblys- one of the TB and one of the Upper Intake manifold
as well

I'll try running only a line to the MAP sensor
and see if I notice a diffrence

 

That is where I have it now. I thought I read that getting the vacuum/pressure source here will make the idle erractic because it is in close proximity to the engine ports.

 

IMO, I don't think that will affect it at all. If I'm wrong, it's because I've NEVER heard anything about that sort of problem before.

 

ok so the MAP sensor source is the bottom nipple facing the alternator on the UIM.... so for the FPR i should use the nipple in the middle of LIM pointing towards the firewall?

thanks

 

I agree with kabooski and i heard the hitman himself say that along with some other tuners.

 

so which way is the best? now im confused........