04 RX-8 OMP Line replacement
 

Just picked up an 04 RX-8 with 58K on a replaced engine. Was installing the Sohn OMP and everything was going good until I moved the OMP lines to put a piece of rubber hose for protection from the radiator clamp rubbing on them. Two of the tubes snapped and I knew I was going to end up replacing them all because of age. I looked for a DIY on this forum but didn't see any. Has anyone done this with the engine in the car?

Yes, I have done it, you just have to remove the upper intake manifold, it's not that big of a deal. While you are there, you might as well test the oil injectors (search) and I would replace them anyway but if they test good reuse them.

So I've put a temp fix on the oil line while I'm waiting for the new ones (still running pre-mix inthe tank). I've noticed no oil coming down the line from the reservoir to the Sohn adapter. Everything seemed to install ok and there is no oil leaking from the area. Was pretty careful making sure the blade was aligned. After I get the new lines in I'll pull and test the injectors at the same time.
Is it possible to install the Sohn without engaging the blade? I would think they would design it so that it wouldn't bolt down if not aligned right.

I don't think so.

When you installed, did you fill reservoir with the clear hose removed from sohn to bleed the air out?

Also, I was thinking about the same thing when I installed mine.. That hose clamp looks like trouble for the OMP lines. I need to get back into mine to get something around them for protection.

Didn't think to bleed the lines since I thought the air would purge out through the injectors. Since I'm replacing the oil lines and will pull the injectors for testing I'll probably bleed then.

I never bled those lines, just premix and drive the car hard for a tank or two, they will fill up. You should bleed the line from the reservoir to the Sohn, it usually has a much higher capacity that the terminal lines.

Yeah definitely bleed the line from the tank to the sohn. That could take forever to purge.. remember it only uses a bit at a time.

I did not bleed the lines when I replaced them (at the same time as rebuilding the engine). But I did premix heavy for the first couple tanks, and after the first few starts I did see the oil moving up the lines. You can disconnect one of the vacuum lines to help it along faster.

Bleeding is not necessary, as long as your reservoir is above the SOHN and the line is clear and goes straight down it shouldn't be an issue. The Oil Metering Pump is a pump, it will suck the premix in. Unless you live somewhere stupid cold and the premix you are using gets too thick.