McKennaR

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I have a bunch of questions, feel free to skewer me in the replies if I should have split this into multiple threads.

Car is a 2005 Base Automatic with 111,000 miles.

The oil in pan is black, yet the oil in the brand new clear OMP lines is a beautiful shade of amber, like fresh oil. The OMP lines were new about 3000 miles ago, not sure if the injectors are, however.

The check engine light is not on, however I am suspicious of the OMP and / or the oil "injectors" due to when I resurrected it from its most recent flood, it didn't smoke at all during any of the restart attempts, and when it finally cooked off, it just puffed for an instant and then nothing.

This is a far cry from what I have seen on You Tube, and it was flooded for a good bit of time before I got it running. Say, roughly 3 months.

My questions are:

Should I be suspicious of the metering pump due to the color difference in the lines vs. the oil pan despite there being no CEL?
Follow up: Without an AP is their any way to test the OMP or injector nozzles short of removing the UIM and going to town?

Is there any way, short of going to the dealer with the car, to tell if MSP16 has been flashed to this particular vehicle? Dealer won't tell me the cars history over the phone.
Thanks

RIWWP

iTrader: (2)

What is your oil burn rate like?

What is the CEL code?

McKennaR

iTrader: (1)

1. Haven't had the car long enough to tell. I've put maybe 50 miles on it during the diagnostic phase, now its in pieces in the garage and I'm trying to tackle

2. There is no CEL. No misfires, no rough idle, no anything...

RIWWP

iTrader: (2)

Ah, misread that about the CEL.

Well, in theory, fresh amber colored oil in the OMP lines and not in the pan would imply zero oil injection. No oil getting pulled/pushed through the lines, to change of oil color.

However, there are several problems with this theory. The biggest one being that in order for none of the lines to be moving oil, the OMP would have to be shut off or all of the injectors are clogged completely. Possibly the pickup point is clogged?

If the OMP isn't working, you will run in limp mode with a CEL, so that isn't the case here.

I'd guess that a clog at the OMP pickup point (pre-split hose that is), or it's actually not something to worry about until you know what your oil consumption rate is.

McKennaR

iTrader: (1)

Thanks for the reply. This car is brand new to me and I have very little history on it from the previous owner and know practically nothing about the engine's health other than the fact that it has good compression, or did 3 months ago as tested at Superior Mazda right up the road from me. In those 3 months it's driven about 50 miles.

My thing is, during the de-flood it didn't smoke at all... coupled with the amber oil in the OMP lines vs jet black 3000 mile old oil in the pan it leads me to believe there's no oil being injected. I've read about OMP's or MOP's failing without a CEL (Possible New Renesis Engine Failure Theory? - RX8Club.com) as well as clogging injector nozzles, etc.

I'm trying to tackle a hard start issue, that didn't make it into my second post, sorry for that. It starts hard cold or hot, 90% of the time flooding unless I shoot a few cc's of 2 stroke oil into the vac ports on the LIM immediately before attempting to start. If I didn't have a good compression test from a Mazda stealership in my hand, I'd have immediately discounted this motor as blown / low on compression.

Any thoughts on the MSP16 reflash? Any to test the OMP w/o an Access Port?

New:
Optima 35
Reman'd starter
Plugs
MOP/OMP lines (injectors are a ?)

Needs:
Coil Packs (originals... never been replaced)
HT Leads (2009 date stamp on wire)

RIWWP

iTrader: (2)

Highlighted your starting problem...

On average, you will have at least one of your coils fail every 30,000 miles (ish). I struggle to believe that they really have never been replaced, but entirely believe they are LONG overdue.

No smoke on deflood isn't a sure thing to diagnose no-oil. Since if nothing else, oil is injected based on engine load, and starting is pretty much bottom of the table for load.

Only 50 miles since the last oil change could easily explain the color difference, if it never got enough movement through the lines. Lots of low load driving in that 50 miles could easily be limiting the oil injection enough that it won't move the oil.


Replace the coils, plus the wires (it's cheap enough). Then do some driving and monitor oil consumption.

j9fd3s

my first Rx8 made it 91,000 miles on its original coils, and my friend has an 04 with 83k on its, original coils and its fine as well. can coils fail in 30k? yes. does every single one? no.

oil color vs oil delivery is two different things, i wouldn't base oil delivery just on color. if there is no CEL the electrical portion of the metering pump is working, but to check delivery rates i think you'd have to pull a line off and actually measure it. not sure if that spec is in the Rx8 shop manual @ Foxed.ca the older cars are around 2-3cc/minute @2000rpm, which is like 2-3 drops, its a small amount of oil.

i worked at a dealership from 2004-2008, and i've seen tons of flooded Rx8's, they seem to flood worse than the older cars, the Rx8's are harder to unflood, but they smoke less than the older rotaries. if anything they smoke so much on an unflood because the gas gets into the exhaust/cat and takes longer to burn off.

three, you can call mazda corporate with the vin and they can tell you if MSP16 has been done, or you can PM me the vin

RIWWP

iTrader: (2)

^ agreed about the possibility existing on the coils. If all coils were equal, they would all fail within a few revolutions of each other. They do not, so there is variance between them. As noted in my post, the odds are that you do not have 4 perfect coils. The odds also exist that there are some people out there that actually do. Of course, this isn't taking into account the possibility that those examples had actually started failing far before then, and it just wasn't detected (not saying it is or not, just acknowledging the possibility)

McKennaR

iTrader: (1)

I assumed the coil packs were a (large) part of it, but it still concerns me that it will only start if I inject 30 - 50cc's of 2 stroke oil into the LIM... Seems to have no problem firing right up at that point, otherwise it'll crank over and stumble and buck and "act" like it wants to catch, but will never actually spin faster than the starter RPM before flooding... that is, unless I shoot the 2 stroke oil in there first.

This reminds me of some of my old piston engine'd cars that were too low on compression to start unless I shot some ATF or MMO into the plug holes on that first crank.

As far as the oil change... perhaps I've been a bit confusing... the last oil change was about 3000 miles ago, around the time the oil lines were re-done. I've only driven it 50 miles from the previous owner's front yard, to the Mazda dealer, to my garage and a few times around the neighborhood since I've owned it.

What I noticed was that the color of the oil in the lines looks as though its brand new, as in it's translucent and amber in color. The color of the oil from the pan when viewed through a similar clear piece of plastic (I used a straw from a juice box for comparison) and back lit using a drop light is a very dark brown, almost reddish black.

This leads me to the conclusion that the OMP / MOP isn't passing oil, or that the system is clogged somewhere down stream from the OMP and it's preventing fresh oil from getting to the rotors.

The no smoke during de-flood was merely evidence that I (perhaps mistakenly?) took as supporting the above conclusion (assumption?). Every de flood story, picture and video I've seen on this site has shown a whole mess of smoke. I got 2 puffs and that was it.

As far as the coils, I ordered some on 28 November and they still haven't shown up yet. The NGK plug wires I ordered as a part of the set arrived via UPS this afternoon according to the tracking website.

Thanks

j9fd3s

yea @111k they are overdue! its a little off topic, but i think there are some contributing factors as to why some last longer than others. spark plug and wire condition matter, the worse those are, the harder the coil needs to work, and that will burn them up. second i don't like that little adapter thing between the actual coil and where the plug wire attaches, seems like a failure point.

its speculation on my part with the Rx8s, but with the 93-97 626's the valve cover gaskets would leak, and this would ruin the plug wires, and then that would kill the coil in the distributor....

RIWWP

iTrader: (2)

I've flooded twice. Once was enough smoke for the neighbor to rush over with a phone asking if she needed to call the fire department. The second had zero smoke. The first was on an engine that ended up being bad that lightly had gotten damaged from my cat failure about 6 months prior, the second was on a fresh reman. Both were without any cat in the exhaust.


Smoke simple is not conclusive of a flood, much less the amount of oil in the gas.


3,000 miles since the oil was last changed certainly should have moved enough oil through the lines. Honestly though, until you have a grasp on oil consumption rate, it's just speculation that will have you running in circles.


Oil in the engine helps to start it is almost always a compression problem. This could be a carbon buildup problem from the excessive rich condition from failing coils that is unseating the seals.

See this thread that was posted a short time ago on a teardown of a Renesis, specifically the section on carbon displacing the seal: https://www.rx8club.com/tech-garage-...-miles-240782/

RIWWP

iTrader: (2)

Agreed. I have never encountered a failure that is as cut and dried as mileage.

There are always affecting factors. Ambient temp, heat cycles of the engine bay, average RPM, peak RPM, standard deviation of RPM, coil heat buildup, wire condition, plug condition (coils can fail really fast if they are run without being connected to a grounded plug), etc... And that is before you get into manufacturing variances.

McKennaR

iTrader: (1)

I just need to get it starting reliably to put a few thousand miles on it before I'll know my consumption rate.

The oil in the LIM thing being about compression I 100% agree with but it baffles me that Mazda would pass this thing on compression if it was so bad that it needs 2 stroke oil to start it every time...

I've gotten pretty good at it, I mean I can probably put the 2 stroke oil in the LIM via cranking sans fuel pump fuse in about 2 minutes, then fire it up. Beats a 40 minute de-flood every time, but still inconvenient for commuting / grocery getting. That's why I was hoping to eliminate the OMP and nozzles as the no-start culprits while I have the engine bay apart. Looks like I'll just have to do the coils, and if its still a hard / no start, look into the OMP again.

HiFlite999

iTrader: (2)

It's kindof a paid to do, but if you pull the battery, you can get to the MOP. Unbolt the lines and shake or leave them sit for a while until some oil drains out. Re-attach the lines. Bubbles will form in them that are easily seen. On the intake tube, there is a line which runs to the MOP. Disconnect it, and plug both the resulting hole in the intake tube and the that hose. This will normally cause a lot of oil to be moved thru the oil injection lines while the car is idling. The battery and tray will be out of the car, so carefully connect the battery to the battery cable with jumper cables. Start the car and let it idle. (It's probably best to put 1 oz/gallon of premix in the gas tank first).

You should then be able to see the bubbles moving in the clear lines.

Details/discussion here: https://www.rx8club.com/tech-garage-...method-225321/

McKennaR

iTrader: (1)

Thanks for the outstanding link! I'm reading through that right now, looks great. Need to wait for the coils to get here before I try anything with the engine running but I'll definitely do this.

As far as the "line that runs to the MOP" all I found was a large "vac" line that runs from pre-throttle plate on the intake tube to what I'd call a "Vacuum block" under the UIM. That little "vacuum block" then separates to each of the oil injectors. My guess is that this is to provide a filtered supply of ambient / slightly vac'd air to some regulator or valve on the injectors themselves...

I couldn't find a single vac line that actually goes to the MOP itself. Just 2 electrical connectors, one for what looks like a TPS and the other I'm assuming is for the pump itself.

Question, will unplugging the connector to the pump itself throw a CEL, or is it only when you unplug the connector for the position sensor? Id try it but the car is not currently in a running state.

Thanks all

dannobre

iTrader: (3)

The oil in the lines will always look lighter due to how little oil there actually is in the lines...so the light shines through and it looks lighter than the oil in the sump....

Unplugging either of the connectors will cause a limp mode and a CEL..... (well not always a CEL...I have a story for that )

McKennaR

iTrader: (1)

I thought that too, until I took some of the oil I drained from the sump and put into a similar diameter, similarly transparent hose (a juice box straw) to compare the two... The oil from the sump was much, much darker than the comparable oil in the metering line tubes.

I found another thread for seafoaming the actual oil injectors, so before I go taking the UIM off and playing with the nozzles, I'll try that.

Thanks

HiFlite999

iTrader: (2)

That's the one.

Dannobre's right: the oil in the lines will always look pretty clean.

dannobre

iTrader: (3)

The juice box straw is at least 4X the size of the OMP lines

McKennaR

iTrader: (1)

I'm in the middle of doing the process described in the link above (disco OMP lines @ source, drain so a few bubbles appear) and decided to put this oil color thing to bed.

The picture shows a drop of oil collected in a red solo cup I left under the disconnected OMP lines overnight. This is on the left and a bit on the right where I spilled it accidentally as indicated by the lines on the paper.

The drop on the right shows oil I drained from the sump. Moving on.

So, knowing I have an issue with oil supply to the rotor housings, I now need to diagnose the location of the bottleneck, whether it be the pump itself, or the nozzles.

Which leads me to my next question:

When I turn the key to "ON" (but not yet start) just as the fuel pump primes the EFI system, is the OMP supposed to prime / pressurize the oil lines and nozzles?

j9fd3s

no. the metering pump itself is mechanical, the oil supplied to the metering pump by the engines oiling system. the electronics only determine the flow rate oil of the pump, they are essentially taking place of a lever connected to the throttle body.

you should be able to start the engine with the lines off the pump, and let them drip. i'm not sure what the spec is on the Rx8, but the older cars are like 2-4cc/MINUTE @2000rpm. its a really teeny amount of oil.

actually you should just premix some oil with the gas and see if it fixes the problem