so i'm having a rough time with the vacuum system. i just put a b18a1 in my 1990 civic si. and pretty much everything is ok except for the map sensor. the d16 map sensor has one drum like solenoid, most likely the FPR cutoff. but the b18a map sensor has the FPR cutoff and a Purge solenoid. the connector for the map sensor works but the connector on my d16 body harness doesnt match up with the connector for the two solenoids. what should i do??


here's the vacuum diagram to display the FPR cutoff and the Purge solenoid

 

as you can see in the d16 vacuum diagram there's only one solenoid next to the map sensor.

 

i just removed my old map sensor on the firewall, and extended my wires to the MAP on the TB.
and i also capped off any unnecessary lines and vacuum ports, and i do not have any problems

im also running a b16 swap if that helps any

 

ok so what about the two solenoids then, should i jsut run the vacuum setup of the d16 on the b18?

 

Hold on there cowboy...

Why are you concerned about what came on the INTEGRA'S firewall? Use the MAP sensor and Purge Solenoid (if you even want to) from the Civic. You don't have to even have the purge solenoid hooked up as it will not throw a code. The MAP on the other hand has to be. This is about direct replacement as you are going to get when it comes to swaps. Factory OBD-0 MPFI Civic getting a Factory OBD-0 B18... doesn't get any more simple as that when it comes to the wiring when swapping a B-series into the '88-91s...

PS - The B18A1 won't have a MAP on the throttle body.

 

ok thanks, yeah thats all i needed to know. so i should just set the vacuum system up according to what's on the civic and block off the extra nipples right?

 

Correct. Really, the only one that matters is the MAP sensor. The rest is just auxiliary garbage.

 

much thanks