bigfsi

alright, so I've run out of ideas at this point. Last ditch effort. I took my 8 in to do recalls because a fuel smell had become very apparent. Replaced fuel pump housing etc etc. turns out one of my injectors was leaking or had a bad o ring on them. So I figured well, injectors are an easy fix (first time rotary, have worked on 4 bangers majority of time), and so I buy the six injectors, just stock replacement, so no increase, and take my UIM off, which I had a little bit more difficulty with than I expected. Once removed I took the fuel rails out, replaced them, with the new injectors and had to use a couple of the old o rings because unfortunately the new ones lacked the bottom rings. Fast forward, put everything back into place, excited to start my 8 again and crossed my fingers. Wouldn't start, flooded the engine and dead battery. (Its -50 degrees with wind here), and I jumped it, unflooded it and it started up, with a very apparent vacuum leak noise and a pretty glaring problem. Car does not stay on at idle, it dies, and it redlines at 6k now? So I did the 20 pump brake reset, no luck. Went and bought an obd2 scanner and read it today. All it reads is an o2 sensor code. Which has been there a while, I know it needs replacing, but it hadn't affected it before I tore all the vacuum hoses out. Also, a couple of other details, had to replace a solenoid from those killer plastic nipples breaking, and the vacuum line that was connected to it. Which I believe operates the VFAD? not sure, it's the middle connector out of the three behind the UIM. Also, removed the tb and air box during the injector replacement. So now, I'm at a real loss. I can't drive it to a dealership, not that I'd want to anyways, they estimated 2500$ to replace my injectors?! So I have to get my 8 back running again. Extra bits of information, when I turn the key to the on position, I can hear the fuel rail pressurize. With an odd liquid noise and a buzzing noise I hadn't noticed before. Not sure if that's normal. So please, any suggestions are welcome, because it's been two months now and I'd just like to get it started again...

Loki

iTrader: (1)

You shouldn't be able to hear your fuel rail pressurize inside the car. That's not a thing. So whatever you're hearing, you'll want to localize it. Air pump, fuel pump, throttle body calibration all make a noise, but nothing that sounds like what you describe. But if you're sure you have a vacuum leak, I'm not sure what help we can offer. Take apart the intake again and find it. It's also possible the vacuum lines got misrouted, you'll want to compare against this diagram.

https://www.rx8club.com/series-i-tec...iagram-214910/

Some variations possible depending on year of car.

What is the 02 sensor code? Are you sure you don't have ignition coil and cat failure?

bigfsi

I'm going to take the manifold off again and perhaps replace the seals inside the manifold? It sounds like a very large leak, but would that cause the car to not idle and redline at 6k? Wouldn't expect coils or cats, considering before I replaced the injectors it started on two turns every morning at -32 degrees, never had any problems, the code is P0037, no other codes at all. And the pressurization sound I'm describing sounds like a liquid flowing through something and a slight gargle or a bubbly sound perhaps? Difficult to describe, I can probably take a video tomorrow. Also the liquid noise is only there for a second, but the buzzing that accompanies it stays.

Loki

iTrader: (1)

People have also mixed up injector wiring, check that they're connected to the correct wires while you have the thing apart.

Do you have OBD data to confirm the vacuum leak? Is it actually starting but not holding idle or not starting at all?

By the way, the 2nd solenoid behind the UIM is the SSV. The VFAD plugs in to the underside of the UIM, and it's easy to forget to plug it in, leaving a medium size vacuum leak.

bigfsi

Obd2 data didn't say anything about it being a vacuum leak, and the car will start after jumping it, but I have to keep revving it to keep it alive

Loki

iTrader: (1)

Yeah that actually sounds a lot like injectors being connected in the wrong order.

bigfsi

Really? I can tear it down and check it, but which all problems would that eliminate? Would a mixed up wiring position cause it to start roughly, not stay on and redline at 6k? I'm assuming the vacuum line issue and the buzzing/liquid noise couldn't be related right?

Loki

iTrader: (1)

You may not have a vacuum line issue at all, just injectors. But either way, getting to the injectors requires getting the intake apart. Without data we can't be certain, but those are the things you last messed with, so logically, the problem is there. And the symptoms do fit incorrect injector order, especially if it's extra silly like one rotor is correctly connected and the other isn't.

I can't comment on the liquid noise, not enough info.