Wankel Wednesday - Obscure Parts Edition

"roflcopter" (roflroflroflcopter)
09/25/2013 at 10:20 • Filed to: Wankel Wednesday, brap

I love rotaries, I'm not afraid to say it. I bought an RX8 with essentially zero car experience and learned my way through. So here's a tale of mystery issues and obscure parts.

The engine bays on these things are ridiculously tight, and getting to anything actually on the block(fuel injectors, valving, coils, grounds, oil injectors) takes removing just about everything.

The problem I was attempting to correct is a tendency to rich out above ~6200RPM(read: when it goes to the open-loop tables). Now most of the time you would immediately look at your tune to fix an issue like this, but the funny thing is that I'm running a stock ECU, with a stock enough engine that it should still be doing fine, so unless the ECU is failing that isn't my problem.

After spending many hours looking for vacuum leaks, seafoaming the engine, replacing coils, replacing and texting new coils, replacing spark plugs and wires, testing fuel injectors, replacing fuel injectors, replacing O2 sensors, swapping MAFs with known working ones, checking CPS outputs, watching data logs of fuel trims, and continuing to be stumped, I thought it might be an issue with the oil injectors injecting too much at high load(it smells like oil when it has oen of it's episodes).

Turns out that two of them tested bad once I stripped it down to the block(see above picture) and I found a used set on a forum and scooped them up cheap.

These injectors are partly digitally controlled, but also depend on a form of vacuum regulation as well, and they have check-valves in them which had failed on two of mine.

After replacing the two bad ones, testing the system as a whole and being satisfied with the results, I put the whole shebang back together. No luck. The hunt continues!

I hope this article wasn't too out of left field, just figured I'd share a glimpse into owning a rotary and trouble shooting parts that most people haven't even heard of, it really puts a new meaning to on your own.

DISCUSSION (16)

Takuro Spirit > roflcopter
09/25/2013 at 10:23

Damn you connecting bolts!

Seriously, that's what they're called.

We sell them on nearly every engine we replace, because they almost always fail the testing procedure we use to check them.

Plus, they're easier to get to when it's the inevitable motor swap time.

roflcopter > Takuro Spirit
09/25/2013 at 10:27

Getting to them is definitely a pain. And even on ones that I knew were good, the testing procedure still wasn't giving consistent results. Still don't know what the main issue was, but I'm willing to assume that those things aren't the issue.

Takuro Spirit > roflcopter
09/25/2013 at 10:31

Probably one of the shutter valve doohickeys in the intake manifold?

roflcopter > Takuro Spirit
09/25/2013 at 10:31

Nope, had the entire thing apart and back together multiple times and everything checks out.

Captain_Overboost > Takuro Spirit
09/25/2013 at 10:42

"the inevitable motor swap time" LMAO The RX8 is the only car I've ever owned where replacing the engine is a routine maintenance item like changing the wiper blades and brake pads. hehehe

Ok, so it's not *quite* that bad, but we "rotards" love our spinning doritos. Otherwise, who the hell would put up with that crap!?

Takuro Spirit > roflcopter
09/25/2013 at 10:44

Time for an LS swap?

Takuro Spirit > Captain_Overboost
09/25/2013 at 10:46

It's the same with a lot of dedicated car lovers.

Like, Subarus and head gaskets.

Fords and ignition coils.

Volkswagons and emissions/vacuum hoses.

Captain_Overboost > Takuro Spirit
09/25/2013 at 10:48

Agreed. But, I'm sure you're on the Rx8club.com forums. That's the only place I've ever been where they keep track of what engine they're on... and wear it as a badge of dedication and honor! lol But, trust me, I get it. If I had all the money I've wasted... errr.. invested... in cars over the years, I could retire comfortably right now. But, riding a bike sucks. I'm waaay too out of shape to wear spandex and those goofy helmets.

Takuro Spirit > Captain_Overboost
09/25/2013 at 10:56

I'm not, but I do work at a dealer.

Hey, we had one that made it 130k on the original engine last week. Automatic too! (They seem to go through motors more often)

I'm in the same boat, but I'm getting to old for this shit, wrenching on the pieces of shit I buy.... I think I'm gonna allow myself ONE more. For now.

roflcopter > Takuro Spirit
09/25/2013 at 10:58

Blasphemy. A blown engine is just an excuse to beef up the internals and port the thing.

MR2_FTW - Group J's resident Stig > roflcopter
09/25/2013 at 11:25

Don't these have an oil metering system as well? Could there be a malfunction with that?

You can tell a Finn but you can't tell him much > Takuro Spirit
09/25/2013 at 11:56

Probably one of the shutter valve doohickeys in the intake manifold?

Best quote ever from the guy who buys parts for a dealer. At least I'm pretty sure that's what you've said you do.

Captain_Overboost > Takuro Spirit
09/25/2013 at 11:56

Yeah, that's what everyone suffering an addiction says, "Just ONE more". I'll be ok, I can quit after "just one more". But, ummm, you know... not now. It's ok though, WE know you can quit any time you want. So you have the love and support of we Opponauts.

Takuro Spirit > You can tell a Finn but you can't tell him much
09/25/2013 at 12:35

I sell parts FOR the dealer. That's what most people would call it. Or worse.

You can tell a Finn but you can't tell him much > Takuro Spirit
09/25/2013 at 13:59

Either way, a parts guy selling "valve doohickeys" is a win in my book.

roflcopter > MR2_FTW - Group J's resident Stig
09/25/2013 at 14:59

They do, but if that we're malfunctioning there would be a CEL for it almost 100% of the time and it's a pretty fail-safe design. That being said, I've had the OMP off the block and checked to make sure the stepper motor is clocked and working properly.