Hey all,

I've been looking for a new fuel pump for my 1985 12A. I currently have an off-brand fuel pump that rock-auto and several other car part sites insisted is functionally the same as the original, but it's smaller, doesn't fit on the mount super well, and makes a high-pitch whining sound. My car has also not been nearly as peppy as it was before the original pump died, especially when the weather's cold. The SKU# for the original fuel pump is 13-400B-N249, and I have not been able to find one anywhere.
Please help, I'm new to RX-7s and this forum. I have never worked on a car with a rotary engine or a carbureted engine before, so I've been a little slow to figure my car out.

Thanks!
-Dan

 

My 84 with a 12a currently has a Rock-Auto pump and I would not recommend the generic one they sell either. I have recently bought a Holley 12-427 and I am hoping that it suits the car better. Even though it is not as cheap I think it is worth paying more for a quality pump. I am going to finally install it in the car this weekend and will report back with the results.

 

You can use the earlier pump which is still available. From Mazdatrix or go to the dealer with the part number.
One of the hoses comes in at a different angle is the difference.

 

Yes the earlier style pump is what I went with too, from Atkins, it's been working fine. Only time I've had an issue with it is when the primary filter starts to get clogged, then it will cut out at high load. I later figured out my in tank strainer had a hole in it, letting the primary filter clog up quicker, till I put a new strainer for a 60s Mustang in it.

 

I agree with getting an OEM pump if you can. Are they still making the OEM pumps or are they all new old stock from 20+ years ago? I got my Holley pump in the car today the car runs beautifully, I wish I switched the pump and routed my fuel lines differently years ago.

 

Does the earlier style pump fit on the mount well? It looks to be really similar in size to the one that I have on there now, and I couldn't get it attached as securely as I would have liked. Also with the Holley 12-427, do you know what the distance is between the two mounting holes? I don't see that anywhere in the specs on Holley's website, though it looks like its mounts are plastic, so they'd be easier to modify a little than the steel.

Thanks for your help!
-Dan

 

The holes lined up perfectly for the older style pump on the newer style mount. I got new fuel hoses and cut them to length so everything would fit without anything kinking, since the inlet/outlet are switched between styles of pump.

I also took the rubber grommets off the dead "newer style" pump and placed them under the bolt mounting points on the new "older style" pump to help absorb vibrations.

Do you know what psi the fuel pump you got from RockAuto runs at?