StarSpinner

Nicely thought out. Case 2 sounds very plausible. Where else would the oil displaced from the pump go if there was a significant obstruction.

But with case three, doesn't the oil injector only see one either compression, or vacuum since it's in a fixed location on the rotor housing? I suppose it would only see slight vac now that I think about it, if it oils only on the intake sweep of the rotor.

And with case four, if you take it a step farther and consider the function of the oil injector with the seal removed.....hmmmm, I think it would just be pulled into the rotor housing in large quantities. Then the flow limit would only be a function of orifice size and oil pressure. So with the seal I'd guess that adds another flow restriction. Which means it needs to work right. Holy smokes, I wonder what it would be like to run four oil injectors with the internal flex seal removed?

I cleaned my oil injectors about a month ago and I had thought that it would increase oil consumption, but it has not been the case so far. In fact taking a peek at the new lines I installed today, I even noticed an air bubble in one of the lines which can't be good. Only driving rarely now thankfully. I'll be re-doing this job again soon but if there is no way to verify the flow or if there is a lot of debris inside that can be loosened with cleaning then clogging the tip, I think the effort is best spent on installing new oil injectors.

s-rx8

I couldnt even guess until I understood the pump better. If it equally opens the 4 ports then I'd say the pressure goes higher in the other 3 and if the volume supports it, that means more oil in those.

I initially thought the same... but I'm only 4 months into my knowledge of the 13b and I happened to read another thread that stated else wise... No clue how though, the compression is all on the other sides of the stroke. I'll gladly admit I could be wrong.

I will argue that point (unless... read on). If the rubber seal is gone, you get what I get now, strait flow from the intake vac port to the tip of the injector... and guess what holes are largest... the vac and the tip, so the banjo holes will bring in oil, but very little bit without suction on those (closed vac port) or high pressure from the oil pump (which I have no guess how much it will do). Now if you want to try that megaoil type deal and you knew your seal is gone... if my theory in this paragraph is correct, you might be better off capping off that vac port to allow exactly what you said, lots of oil (instead of little to none). It will at least hold you off until you can afford new injectors (and probably a new cat and o2 sensor).


I'd guess that if you are getting air, the sump might be running dry, the oil tubes have a leak, or the oring on the back of the OMP is toast? Thats my kindergarten rotary knowledge speaking.

As far as my thoughts on these injectors and my engineering mind... I'd right now sum up these thoughts:
a) that coking happens from a hot engine while no oil flow
b) do not shut down after a hard run because of that, treat it like the same as if you had a big turbo setup where you want to keep the oil flowing until the temp comes to normal.
c) topside of the engine gets hot, what to do about it? overkill would tell me to run a cooling fan for 10 min after shut down, maybe vent the hood too, again, overkill.
d) cleaning the injectors? good luck. I'd do what you can with some non abrasive cleaner then test the vac on each of these injectors every so many miles and put it in the maintenance procedures.
e) My thoughts to many of what I've heard of rotary problems can be highly contributed to these injectors. The more I think about it the more I want to premix. Even if you had the injectors working fine, how good is excess 4 stroke oil in the chamber anyway? It will lead to a dirty engine eventually. So how to counter that? High rpms? Sea foam? Premix? Water injection (for steam cleaning)?

Many of my comments may be wrong, take it with a grain of salt, its made to start discussion so we all can get knowledgeable. My youth in the rotary regime is too new to know all the things to consider.

Shawn

ZiG

The outlets on the OMP are in parallel, so you shouldn't see different flow rates unless something is blocked. While prepping for my first start I tried to draw oil into the (brand new) lines with limited success, so I have been running premix since the very first tank. I did notice that when I pinched off the main vacuum line at idle, the oil seemed to flow a little faster through the lines. I figured that was because the engine wasn't able to pull air through the vac line and instead the rotor was forced to pull more oil through the injectors during each intake stroke.

Also, I have been using a Sohn adapter since day one so it will be seeing nothing but clean oil from now on. Hopefully that will go a long way towards keeping the injectors clean. I even started with Idemitsu (clear) and then switched to Amsoil Saber Professional (dark blue) to verify consistent, even flow in all the lines. Would probably recommend that method to anyone with a fresh rebuild as it takes out a lot of the guess work.

ZiG

Just a quick update for the sake of it. I ordered new injectors and replaced the 3 old ones I had. Used my built in vacuum tester on the old ones and they didn't seem to seal perfectly, no idea if it was more or less than 10 inches of vacuum or not, but I would have to guess so. The new ones sealed perfectly (near as I can tell). I can see from my sohn tank that I was still using oil the whole time though, so my gut tells me they were not too far gone.

s-rx8

Using oil is goodness... so far I have had no luck at all getting my old ones to seal... the new ones hold any vac... from 1 psi to spec. My engine is now ready for drop in... hopefully this weekend it will be installed... thanks for update!
Shawn

StarSpinner

Thanks for the update. I suppose the take away from this thread is that new oil injectors are advisable if servicing.

ZiG

Yeah, pretty much. Since they're so critical, it makes good sense to do them rhyme you're spending all that money on a rebuild anyways.

FunRun8

iTrader: (5)

I know this is a bit late but here ya go for anyone who wishes to gain more understanding of the injector system function.
https://www.rx8club.com/series-i-maj...-249315/page2/

Doh! Just realized someone already beat me to it, oh well, here it is anyway.

dannobre

iTrader: (3)

Why would you bump that thread? There is so much info in there that is misguided and confusing...quite a bit on your part that it is almost useless

😐

FunRun8

iTrader: (5)

Really? I don't believe there is, the thread never ran it's course to a finality, so please show me why it is misleading? Share with me/us your vast knowledge of the injector functions instead of just criticizing because there is nowhere else besides this thread that ACTUALLY does that I've seen? Before you do please take into account that I have dealt with similar systems for more than 35 years so I do know a thing or two.

kylerunner1

What was the name of that little plastic splitter that the injector breather hoses go to. Like you said they become brittle and I had one of the nipples on it just break right off but I can't find it anywhere. Does it need to be replaced or is there an alternative method for fixing it. Any help greatly appreciated I am in a bit of a bind here. Thanks!

dannobre

iTrader: (3)

That's a Mazda specific part. You will need to get it at the dealer. It will be a special order so expect a couple of days at least depending how close to one of the distribution centers you live

kylerunner1

OK thank you. I would still like to know what the name of it is. Can I drive the car just a short distance without it I believe it is just there to ensure the injector gets CLEAN air but a short drive shouldn't suck anything up in it I wouldn't think. Is there a way to go around this part? Maybe make my own manifold with its own filter?

kylerunner1

OK I have found the name of the part and the part number if anyone needs it in the future. This is the part that the oil injector hoses connect to. It is called a fuel rail insulator distributor for the injectors and is part number N3H113158. You can get it on eBay or the dealer and is $40, wow!