Hey everyone, I have a 91 civic with a SOHC ZC swap.. Not sure if my vacuum lines are set up correctly or if I even have the right manifold for the car, because I cant seem to find diagrams with the same nipples I have on mine... I bought the car with the swap done and its really never ran right to me. Can anyone get me a picture of their vacuum line setup for a 5 speed SOHC ZC 88-91. Also is the dashpot really needed? When I bought the car it did not have one, I found one that I thought would installed it and ran the car for a while but it only has one inlet and after researching it I found out that its from a DOHC. And the SOHC needs in and an out. Do I absolutely need it or can I bypass it somehow... If anyone could post pictures of their vacuum line setups that would be great! Thanks!

 

Does your intake manifold have the FICV as indicated in the first picture? If so, leave the dashpot alone and use the first diagram. If your intake manifold doesn't have an FICV (fast idle control solenoid valve), use the second diagram.
Also, if you have the FICV and have done an MPFI (multi point fuel injection) conversion you won't have an electrical connector on your engine harness to plug into the FICV. In that case, plug up the FICV ports and use the second diagram.


'89-'91


'88

 

I think one of my diagrams below is identical to one that Trust posted.

By the way, in a recent thread, you mentioned that your ECU is throwing code 20 (electrical load detector - ELD). What ECU do you you have? I didn't think that 4th generation Civics have an ELD.

 

I think I had the PM6 ecu the Si ecu, and it threw a code 20. I put in a PG7 ecu and it still threw that code.

The first diagram from trustdestruction is what I have. Is that the proper manifold for a SOHC ZC? Im assuming the ZC is the same as the Si manifold.. Also from the looks of it I dont need a dashpot that has an in and an out then? Im guessing mine is okay only having 1 nipple on it from this diagram. Just to make sure on the diagram it looks like the lined labeled #6 goes from the left nipple at the front to the dashpot then to the back of the motor?? or is that something else?