BigIslandBoi

heres the problem...
finished swapping an OBD1 B18C1 into my 90 OBD0 DA. used the OBD0-OBD1 conversion harness that i bought from someone on this forum. Used the LS engine harness and the P72 ECU.

Only problem now is NO VTEC?!!!! used my friends Type-R ECU and the VTEC works fine. Obviously the ECU is the problem.

So my question is: Can I use the P72 ECU and just run an Apex VAFC to get the VTEC to kick in?

Kamin

wait

you used a LS engine harness with a VTEC engine?

there are no vtec plugs on a LS harness so even with the ITR ecu vtec never worked.

and if you DID wire it up did you make sure to wire in the IAB's? (butterflies in the GSR manifold) if you didnt you will NOT hear or feel the GSR's vtec kick in at 4400. (YES 4400)

BigIslandBoi

yes i used an LS harness and yes I wired up the VTEC wires to the ECU, so I didn't need any VTEC plugs. The secondary butterflies i kept open. my question was if using the VAFC with the P72 will enable the VTEC?

Kamin

yes a p72 has vtec, its a GSR ecu

now you did wire the IAB's right?

BigIslandBoi

dont need the IAB...Im gonna leave the secondary butterfly open

Kamin

you need to run the IAB's
running them open all the time will hurt your performance.

not to mention you say you dont hear vtec, thats because at 5700. when the IAB's open. they are already open. you wont hear the vtec on a GSR when it engages at 4400, the stock spot. the reason you "heard" vtec with the ITR ecu was because it engaged so late.

BigIslandBoi

ic...so can i use the VAFC with the P72 with the IAB connected?

Kamin

you dont need a VAFC with a p72 ecu. the p72 will control everything fine.

VTECVillain

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Can I use the P72 ECU and just run an Apex VAFC to get the VTEC to kick in?</TD></TR></TABLE>

If the P72 ECU is working properly then the only reason that the VTEC solenoid/pressure switch isn't functioning properly is due to the wiring which could be the OBD0 to OBD1 harness or your wiring. The only reason you should use a VAFC is to tune your setup not to make the VTEC function properly as it should already be.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">used my friends Type-R ECU and the VTEC works fine. Obviously the ECU is the problem.</TD></TR></TABLE>

I don't see how you used an ITR ECU with your harness considering the ITR ECU is only OBD2 and OBD2B which won't plug into OBD0/OBD1 plugs.