Hey I recently swapped a B18C into my 95 Civic Coupe.All of it is OBD1 for sure. I have a JDM comp and i used an LS harness. I wired in Vtec the Knock and a few other things that werent there myself. Now everything is hooked up and wired in fine. I have looked it over and been over all the steps. I checked my solenoid and it works. But my Vtec oil pressure switch is not engaging and letting the oil flow through. Why could this be??

 

o yeah sorry there are no DTC's.

 

hmm no one knows??

 

some one has to know iam having the same problem but i used a 95 hatch harness and iam turboed as well?..

 

?????

 

Wow 20 veiws but no one has a answer for me.

 

Check your oil level...
If its too low, there is not enough oil to engage the piston in the VTEC solenoid...

 

its all in the harness and u say u rigged the vtek so need to see if they are in the right place and used the right color wire just double check u will thank me

 

I double check all the wiring and everything. All of it is right. Will a bad altinator do this?? b/c right now 2 diodes are bad in the rectifying bridge which will create a flow of AC in my electrical. Will this cause the oil pressure to be fooled?? B/c my Vtec still isnt working if not how can i tap into the block for oil pressure. (manual reading)

 

No, a "bad", (as in doesn't put put any voltage) alternator should have no effect on VTEC engagement... Try running the car without the alternator connected. (only drive down the road to see if VTEC engages)
VTEC engagement is controlled by DC voltage, not AC.

Check your VTEC grounds... If they are corroded, it could cause enough of a resistance to disble VTEC, but not enough to throw a CEL? This is unlikely...

Another thought, knock sensors use AC voltage to to detect knock. Maybe if your alternator is putting AC voltage into the computer, it could be causing a it to recognize this AC as knock, and severely retard the ignition and disable VTEC from engaging.
If the computer sees knock, it will NEVER activate VTEC because it would surely damage the motor. Hence the 93 octane requirement. If u use an octane with a rating less than 91, this introduces knock, and the computer compensates by retarding ignition timing and disabling VTEC.

Try this... Simply drive with the alternator disconnected. (make sure it is fully charged so u don't get stuck on the road). If VTEC engages, its the alternator.