I have a 1987 fc rx-7 gxl that i bought an omp elimination kit for. I currently have the upper intake manifold off my car and am working to get the lower intake manifold off so i can clean it out and fix the actuators. In this process i saw that the OMP lines connected into the lower intake manifold, and i thought that since i planned on doing an OMP delete at some point, i might as well just do it in the process.

My question is, i saw some people saying the car will end up on limp mode if i dont get a standalone ecu, but i dont know what gen they were speaking of. Is that necessary? My other question is, if i do the removal, what do i do with the 3 nipples that the vacuum hoses connected to on the dynamic chamber? Im way newer to all of this so any help would be greatly appreciated. I know premix at that point will be necessary so i am not sure. It’s not necessary and i could totally keep it on, which could very well be the best option, but i would like to hear it from some professionals or more experienced people. Thank y’all!

 

The 1987 is an S4 and I didn't think it had the feed to the ECU. I thought only the S5 second gen had that.

 

I believe so, i’m just not entirely sure. If that’s true then it wouldn’t be so bad to delete omp.

 

It has a mechanical omp so won’t put the car in limp mode if removed. I’d say leave it on.

 

Maybe this isn't what you want to hear but the S4 has one of the most reliable OMP (maybe when compared to the S5) and it actually is best to leave it on? It's mechanical, super simple to rebuild, and is extra insurance to keep your engine running healthier, plus you can premix on top of that.

Throw a mechanical Sohn adapter on and you're even more golden.

https://sakebahn.com/shop/84-89-mazda-13b-omp-adaptor/

 

I’m honestly more convinced and chose to run the omp. If something breaks i have the elimination kit, and it doesn’t hurt premixing as well. My issue now is that the car doesn’t want to idle after we reinstalled and fixed the actuators and sleeves! The actuators work great, but i believe it’s a bad vacuum leak or the MAF is broken. We’ll just have to see. It starts, fires, and we can get it to hold gas, then it just shuts down. This is a disaster, hopefully i’ll have it sorted out soon.