Where do you go to get a replacement omp? Can you swap out an S4 computer and convert to the older style OMP?

 

Or do I just do another LS swap? I was hoping to drive a rotary for the 1st time for a little bit....LImp mode is no fun!

 

Check/ask in the 2nd Gen classifieds.
Of course you could purchase one from Mazmart:
https://mazmartstore.mybigcommerce.c...7-fc-series-5/

 

Power FC would be an option as well, it doesn't care about the metering pump

 

A better question may be can a 3rd gen (FD) OMP be made to work on a S5. Is rewiring the FD plug to match the S5 FC all that is needed? FD OMP can be gotten for less than $200 on Ebay. vs. over $500 for an FC one.
RX-7 Metering Pump for sale | eBay

The PowerFC that j9fd3s mentioned or about any standalone is cheaper than a new OMP. With a standalone you would just delete and run premix.

 

yes, there are a couple of differences between the pumps, but the pieces swap over.
the main body (aluminum) only has 2 metering line holes instead of 4, but otherwise appear identical.
the harness has a different plug at the harness end, but the pump end, and position sensor are the same as the FC.

there are people on Yahoo Japan who are selling rebuild kits, its like all the O rings, 2 bearings, connectors and some other stuff

 

Before you replace the OMP, I'll ask if you've gone thru all the steps in the FSM to verify that the OMP is indeed the problem, and not an issue with old crispy wiring or the ECU? The electronic OMP's in the S5 FCs and FDs are pretty robust and rarely fail. Troubleshooting excerpts cut & pasted from the FSM below....