1994 RX-7: Xcessive LIM & Fuel Rail install (in progress)

[scotty305]

I haven't made much progress lately... past few weeks got busy at work, plus Christmas and New Years and family stuff. I purchased some AN fittings but they are larger than I realized, my fittings aren't fitting. My revised fuel setup will include an aftermarket FPR designed for a Honda setup which mounts directly to the fuel rail using a flange with an o-ring. Mounting the regulator to the fuel rail will eliminate 5 fittings and adapters compared to my original plan (NPT-to-AN male, AN-female to push-on hose, push-on hose to AN female, AN male to AN male). I'm hoping to finish that within the next week or so.


The OEM lower manifold includes four vacuum pass-throughs (near the top)... I'm removing one of those lines (EGR) and planning to route the other three (used with the Charge Control and Charge Relief valves) around the rear of the manifold near the firewall.

The vacuum line near the front secondary intake runner supplies air for the primary injectors, that passage is not retained with the XS LIM so the vacuum line will not be necessary.

The other vacuum line is just manifold pressure, the diagram isn't clear but I think it is used for the OEM fuel pressure regulator. After eliminating the AWS, ACV and EGR solenoids there will be at least one unused port on the UIM near the throttle body... one of those ports will feed vacuum/boost directly to the FPR (the OEM Fuel Pressure Control solenoid will be eliminated).