Kind of a weird question/situation here.

97 Civic hatch
95 LS B18B1 swap
Running P75 ECU (proper ECU)


I have the OEM MAP sensor that goes on the b18b1 (on the throttle body). However, if you attempt to use that MAP sensor, the car idles at 100rpm and then dies.

But, if I plug it into the MAP on the firewall (with an exposed nipple on the bottom, that connects to a "useless" vacuum port on the rear of the IM), the car runs 100% perfect.

I attempted to "plug" the vacuum port on the rear, and it made no difference. It needs to feel the pressure (obviously) fed into the bottom of the nipple on the MAP sensor.

Also plugged a p28 into the car, to see if it was ECU...and it is the same thing.


Anyone have any ideas?

What I want to do is use a MAP sensor on the TB, instead of the firewall (wiretuck).

 

Nothing?

 

why do you have a map sensor on the firewall? is it a honda one?

vacuum port on the rear of the intake manifold goes to the the evap purge solenoid.

is it possible you have the wrong throttle body gasket? i can't see any other reason it would run any different with it plugged in unless the map sensor is junk.

 

Quite a few Honda's came with the MAP sensor on the firewall (i.e. my old d15b7 93 sedan).

I don't understand the last statement you made.