OMP Oil Metering pump output and modification
#201
77 cylinders, 4 rotors...
Because I couldn't find it! Now someone will post it in 30 seconds...
The following 2 users liked this post by TeamRX8:
4m4s0 (05-29-2020),
homebuiltracing (05-27-2023)
#203
77 cylinders, 4 rotors...
Thanks, that is a great addition to this thread. I know it was posted to the site about 15 years ago, but its good to bring it up here again, for all of us noobs.
#204
New Member
Oil connections and adjustments
Hi. First of all, I want to thank all the contributors here, especially Brettus, TeamRX8 and kevink0000.
Problem:
I got the MIL on with the code P1688 and limp mode was driving me crazy.
Troubleshooting:
The first thing I tried was adjusting the position switch sensor per every OMP problem-guide.
No luck!
Began troubleshooting as instructed here: DTC P1686
Took every single step!
At #6: METERING OIL PUMP INSPECTION
"Metering Oil Pump Resistance Inspection" gave me 32.6 Ohms between all testing pins. "Positioning Switch Resistance Inspection" gave me around 100 Ohms which is alright.
"Oil Nozzle Inspection" was the only test I couldn't do since I don't have a vacuum pump nor any meter or gauge.
Everything else seemed alright. Even between the Pcm-connections and the OMP and OMP-switch.
So I decided to look for internal problems.
Solution:
Since I couldn't find any info about how the OMP should behave during the startup check I tested it myself by filming the cam shaft through the hole for the position switch. (while connected to the car of course)
It looked like it was trying to move (shaking) for the first 10 seconds. But I don't know how it's supposed to behave, so I continued troubleshooting and taking apart the whole OMP:
Apparently the stepper motor was stuck!
So after some WD-40, 5-56 and bearing grease and trying to turn it by hand I finally managed to make it turn smoothly.
Put it all together, and on to the car, et voilà ! No more MIL! (after 4-5 tries or adjusting the position sensor).
But, before this I filmed the hole once again, and I found that in the first 10 seconds, the stepper motor turns the cam shaft around 90 degrees counterclockwise twice (looking for signal from position sensor i think).
My question:
How can I know if the OMP is getting oil to the engine?
How should the oil feed lines be aligned?
Problem:
I got the MIL on with the code P1688 and limp mode was driving me crazy.
Troubleshooting:
The first thing I tried was adjusting the position switch sensor per every OMP problem-guide.
No luck!
Began troubleshooting as instructed here: DTC P1686
Took every single step!
At #6: METERING OIL PUMP INSPECTION
"Metering Oil Pump Resistance Inspection" gave me 32.6 Ohms between all testing pins. "Positioning Switch Resistance Inspection" gave me around 100 Ohms which is alright.
"Oil Nozzle Inspection" was the only test I couldn't do since I don't have a vacuum pump nor any meter or gauge.
Everything else seemed alright. Even between the Pcm-connections and the OMP and OMP-switch.
So I decided to look for internal problems.
Solution:
Since I couldn't find any info about how the OMP should behave during the startup check I tested it myself by filming the cam shaft through the hole for the position switch. (while connected to the car of course)
It looked like it was trying to move (shaking) for the first 10 seconds. But I don't know how it's supposed to behave, so I continued troubleshooting and taking apart the whole OMP:
Apparently the stepper motor was stuck!
So after some WD-40, 5-56 and bearing grease and trying to turn it by hand I finally managed to make it turn smoothly.
Put it all together, and on to the car, et voilà ! No more MIL! (after 4-5 tries or adjusting the position sensor).
But, before this I filmed the hole once again, and I found that in the first 10 seconds, the stepper motor turns the cam shaft around 90 degrees counterclockwise twice (looking for signal from position sensor i think).
My question:
How can I know if the OMP is getting oil to the engine?
How should the oil feed lines be aligned?
The following users liked this post:
Shaozhou Zhang (05-31-2020)
#206
New Member
I mean the small holes in the bolts shown in this image
As you can see in the image I taped the thin oil lines differently so I could put them back in their right places.
So now I just wanna make sure everything works and the oil is making it to the injectors since the MIL/DTC only reacts to errors between the position sensor and the stepper motor.
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Spinningdorito (09-02-2021)
#209
New Member
#211
New Member
#212
FYI for the record, I have had mod#2 running on my car now for about 4 months now with a Sohn, and I average about 1200 to 1300 miles per quart of 2 stroke oil in normal street use, with a mix of highway and city driving, at about 18.5 mpg average over many tankfuls. I measured the output on a test jig,( I am sure much less sophisticated than Brettus's;I merely measured time/vs the number of drops of oil! ) before I ran the pump on an actual engine, but got a similar looking graph of output rates.
So, FWIW I personally don't think its too much oil, in fact still less than my old 12A FB mechanical OMP would use with stock OMP setting, at less than half the HP output of the 13B-MSP.
Mazda really had to starve this engine of oil to get it to market, past Ford, or past EPA/EU regs, or whatever. Too bad, really.
So, FWIW I personally don't think its too much oil, in fact still less than my old 12A FB mechanical OMP would use with stock OMP setting, at less than half the HP output of the 13B-MSP.
Mazda really had to starve this engine of oil to get it to market, past Ford, or past EPA/EU regs, or whatever. Too bad, really.
I've now done the same mod for my turbo engine (I also drilled the extra holes in piston sleeve) . I dialled the ecu setting back a little below 100% load and taper it out to the max settings in boost. so far not noticing excessive oil use.
Last edited by Brettus; 08-03-2021 at 03:58 PM.
#213
77 cylinders, 4 rotors...
You still doing this ? Any updates ?
I've now done the same mod for my turbo engine (I also drilled the extra holes in piston sleeve) . I dialled the ecu setting back a little below 100% load and taper it out to the max settings in boost. so far not noticing excessive oil use.
I've now done the same mod for my turbo engine (I also drilled the extra holes in piston sleeve) . I dialled the ecu setting back a little below 100% load and taper it out to the max settings in boost. so far not noticing excessive oil use.
For a normal commute week, with mixed highway and stop and go, at about 20 mpg, I use at a ratio of about 55:1 -60:1 including the premix amount I use. When a lot of full throttle is used, the oil consumption goes up dramatically. Also, never fouled, never flooded at these ratios.
My ECU is stock. I chose to mechanically alter the delivery rate initially, and kept it because I was getting close to what I wanted. The plugs are amazingly clean also, and the rotor is totally clean as far as I can see through the plug holes, except for a small patch of carbon in the bathtub, and this is after about 50000 miles of use with this setup. But, I am not injecting 4 stroke oil. I am using what I think is a good 2 stroke oil in the Sohn and premix.
The following 2 users liked this post by kevink0000:
Brettus (08-03-2021),
wannawankel (08-05-2021)
#215
No respecter of malarkey
iTrader: (25)
no, full pre-mix is always the 100% correct answer for a rotary engine
the only reason these other issues exist is because people refuse to accept the truth of it
any way, didn’t realize I had dropped this in the noob forum area, moving here instead:
supposedly coming soon, made in the USA, E85 compatible.
https://renewablelube.com. (not listed on the website yet)
.
the only reason these other issues exist is because people refuse to accept the truth of it
any way, didn’t realize I had dropped this in the noob forum area, moving here instead:
supposedly coming soon, made in the USA, E85 compatible.
https://renewablelube.com. (not listed on the website yet)
.
#217
77 cylinders, 4 rotors...
Team,
Not so.
Not in any total loss system in any engine ever made in the universe of engines is full premix always (100%) best.
The throttle position tells the tale... Its never "best" to have a fixed lubrication rate with highly variable power levels (burn rate and load) in a total loss engine.
Additionally I took Eric Meyer's experience seriously with regard to side seals and OMP operation in road racing. What did you think of that?
I believe the OMP plays an important part in Renesis longevity in any setting. I don't see how it could not. Neither can you, I assert.
Is it the only way, no. I believe both methods benefit the engine if used simultaneously. But used on their own, both have flaws. Used together, they are complementary in my opinion.
Putting this up for further discussion.
Not so.
Not in any total loss system in any engine ever made in the universe of engines is full premix always (100%) best.
The throttle position tells the tale... Its never "best" to have a fixed lubrication rate with highly variable power levels (burn rate and load) in a total loss engine.
Additionally I took Eric Meyer's experience seriously with regard to side seals and OMP operation in road racing. What did you think of that?
I believe the OMP plays an important part in Renesis longevity in any setting. I don't see how it could not. Neither can you, I assert.
Is it the only way, no. I believe both methods benefit the engine if used simultaneously. But used on their own, both have flaws. Used together, they are complementary in my opinion.
Putting this up for further discussion.
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SiNfidelity (07-24-2022)
#218
No respecter of malarkey
iTrader: (25)
Sorry, Eric was flat out wrong on that particular point, as are you wrt his reference. I understand what you’re say in principle for a street emissions car toodlng around with a cat converter, but let’s not ignore that to this day it’s still complicated, expensive, and troublesome, yet also still continues to be all those things as either a mechanical/electrical solution that can fail at any given moment.
Premix is a pain for a poor gas mileage, daily driver, but most owners aren’t going to forget. A stranger etc might just put gas in. A racer has no excuse. Eric was racing, the claim that premix was causing his failures just isn’t correct. There are too many Renesis race engines that proved otherwise, including on this forum after those statements were made. Unless of course you’re also claiming that every Renesis race engine builder is intentionally directing racers to ruin their engines by recommending premixing.
that was my only point and I’m clarifying it as such. Premix done properly works.
Even Rob Dahm said so on YouBoob recently; end of story. :j/k:
.
.
Premix is a pain for a poor gas mileage, daily driver, but most owners aren’t going to forget. A stranger etc might just put gas in. A racer has no excuse. Eric was racing, the claim that premix was causing his failures just isn’t correct. There are too many Renesis race engines that proved otherwise, including on this forum after those statements were made. Unless of course you’re also claiming that every Renesis race engine builder is intentionally directing racers to ruin their engines by recommending premixing.
that was my only point and I’m clarifying it as such. Premix done properly works.
Even Rob Dahm said so on YouBoob recently; end of story. :j/k:
.
.
Last edited by TeamRX8; 08-27-2021 at 08:46 AM.
The following users liked this post:
wcs (08-27-2021)
#220
77 cylinders, 4 rotors...
Team,
I guess you took what I said about Eric as if I fully agreed with what he concluded about the side seals. I know full well that many if not most roadracers use premix only, and do not see the failure modes that Eric spoke about. I said what he saw is worth taking seriously. He also noticed lower EGT with the OMP in use, that bears some consideration in my opinion.
In my 186000 mile teardown, the side seals and irons on the undamaged housing showed almost no wear on the faces of contact. There were huge clearances between the side seals and corner seals, however, which may have been due in part to the large clearances spec'ed in 2007 when the engine was built. But, the front iron will be reused in my rebuild. Many other teardowns show similar wear characteristics. The oil seals and cutoff seals were also within reuse spec, but I won't be using those. The step wear is under reuse spec and the hardness in the worn area of the step is not compromised. The chrome housings showed lots of metal to metal contact, and very uneven wear, some places still had the as-new flouride coating showing, and other areas were worn to the steel liner. And, the side faces of the apex seals were very worn, from rocking in those too shallow slots in the rotors. ( the major Achilles heel for this engine in my opinion) The OMP system's limitations were in evidence in my opinion. The irons, and associated seals, were worn so little they looked like they came from a different engine than the chrome plated housings.
While I always agree that Mazda made some blunders in the Renesis design, the OMP system seems to deliver adequate lubrication where it is aimed, even with the tiny amounts the factory settings deliver. I think what Eric was seeing in his cars re: EGT was also to be considered. And again, lots of racers use premix, but how could it be best on its own? Let's use common sense, a forgotten concept on this forum too many times. Premix only might be adequate for racing, but not optimal. On the street, where I personally am concerned with longevity above other considerations, I believe both approaches have merit, that is why I use both. I think others, racing or street, should do the same.
That is why I wanted to discuss the OMP more, not descend into "You're wrong, he's wrong, everyone's wrong."
I guess you took what I said about Eric as if I fully agreed with what he concluded about the side seals. I know full well that many if not most roadracers use premix only, and do not see the failure modes that Eric spoke about. I said what he saw is worth taking seriously. He also noticed lower EGT with the OMP in use, that bears some consideration in my opinion.
In my 186000 mile teardown, the side seals and irons on the undamaged housing showed almost no wear on the faces of contact. There were huge clearances between the side seals and corner seals, however, which may have been due in part to the large clearances spec'ed in 2007 when the engine was built. But, the front iron will be reused in my rebuild. Many other teardowns show similar wear characteristics. The oil seals and cutoff seals were also within reuse spec, but I won't be using those. The step wear is under reuse spec and the hardness in the worn area of the step is not compromised. The chrome housings showed lots of metal to metal contact, and very uneven wear, some places still had the as-new flouride coating showing, and other areas were worn to the steel liner. And, the side faces of the apex seals were very worn, from rocking in those too shallow slots in the rotors. ( the major Achilles heel for this engine in my opinion) The OMP system's limitations were in evidence in my opinion. The irons, and associated seals, were worn so little they looked like they came from a different engine than the chrome plated housings.
While I always agree that Mazda made some blunders in the Renesis design, the OMP system seems to deliver adequate lubrication where it is aimed, even with the tiny amounts the factory settings deliver. I think what Eric was seeing in his cars re: EGT was also to be considered. And again, lots of racers use premix, but how could it be best on its own? Let's use common sense, a forgotten concept on this forum too many times. Premix only might be adequate for racing, but not optimal. On the street, where I personally am concerned with longevity above other considerations, I believe both approaches have merit, that is why I use both. I think others, racing or street, should do the same.
That is why I wanted to discuss the OMP more, not descend into "You're wrong, he's wrong, everyone's wrong."
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Spinningdorito (09-18-2021)
#221
77 cylinders, 4 rotors...
Another observation
Another observation I was able to make by accident. On an engine I finally finished, I was replacing some of the OMP output lines since I made my own and did not route some correctly.
After I replaced the lines, and was going to finish the next day, the system self bled overnight (with Sohn) using gravity, but only on the lines without the banjo bolts (with the check valves) yet to be installed. The pump doesn't have any positive stop internally, relies on the external valves only, and has enough internal clearance to allow oil to migrate within only using gravity, and a small head height (less than 12" from Sohn tank height to top of engine where oil lines terminate.) This was observed a couple of years ago on the pump on my test bench as well, which was a different pump than the one in the above example.
So, pressure change at the pump intake would conceivably change the pump output beyond what the metering system was calling for. Further evidence that the system was not designed to use any pressure at the intake. If present, it would overwhelm the metering system, and provide more oil than the ECU intended, which we all know is a no-no. This is on an S1. The S2 meters oil at pressure.
After I replaced the lines, and was going to finish the next day, the system self bled overnight (with Sohn) using gravity, but only on the lines without the banjo bolts (with the check valves) yet to be installed. The pump doesn't have any positive stop internally, relies on the external valves only, and has enough internal clearance to allow oil to migrate within only using gravity, and a small head height (less than 12" from Sohn tank height to top of engine where oil lines terminate.) This was observed a couple of years ago on the pump on my test bench as well, which was a different pump than the one in the above example.
So, pressure change at the pump intake would conceivably change the pump output beyond what the metering system was calling for. Further evidence that the system was not designed to use any pressure at the intake. If present, it would overwhelm the metering system, and provide more oil than the ECU intended, which we all know is a no-no. This is on an S1. The S2 meters oil at pressure.
Last edited by kevink0000; 02-23-2022 at 11:55 AM.
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DocWalt (02-25-2022)
#222
Thanks for that Kevin . Further adds to our discussion at the beginning of this thread about drilling the extra holes etc.
FWIW : My turbo engine is still running sweet at 9.5 psi max boost . Mod 2 (large piston in place of small) done almost a year ago and no premix.
FWIW : My turbo engine is still running sweet at 9.5 psi max boost . Mod 2 (large piston in place of small) done almost a year ago and no premix.
#224
77 cylinders, 4 rotors...
Great! I was thinking about asking you if you had decided to run the pump. I now have 2 cars running with the 2 large pump mod, and both with the reindexed sector gear as well. The latest one my MUP engine (Mostly Used Parts ) has 6 injectors running off the modded s1 pump.
Last edited by kevink0000; 07-11-2022 at 08:51 PM.
#225
77 cylinders, 4 rotors...