I'm having the same problem. I also have the b18a1 map sensor and vac fittings, but they won't bolt up to the '91 CRX Si wiring harness (there have actually been a bunch of wiring problems so far, if anybody knows of a good place to look for b18a1 wiring in a CRX, please let me know). Are T-fittings the way to go with the vac on the CRX map sensor?