Really confused now about OMP...(new guy post,kinda long)
03-07-02, 05:48 PM
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Really confused now about OMP...(new guy post,kinda long)
Yes, I am new here...Yes, this is my first rotory experience...Yes, I bought a book and I most definetly tried the search option...which is the main reason I'm so confused...
A little about me and my car first...I have worked on everything from single cylinder motors to inline 24s, but this is my first foray into rotorys...I just got an 86 n/a that was constantly flooding on the guy and he didn't want to mess with it (just for the record when I popped the hood to look at the motor, he said," I ain't never seen nu'in like that afore.") he traded 2 fishing poles for it and I gave him $50...I figure if worse comes to worse...I know a junkyard that will give me $100 for it...but then I wouldn't be havin so much fun learnin new stuff
Anyways...I did the whole unflooding thing and got it to start and run until water started shooting out from between both sides of the waterpump housing so I shut it down and started to take the waterpump off to replace the gaskets...and thats when I noticed the funny lookin little thing with the 4 hoses going to it...or in my case...supposed to be going to it...
3 of the 4 hoses are off...and I say off bececause I don't mean disconected, I mean they are off...with the little cone shaped piece that looks like it goes inside the hose stickin up....
Now, I tried the search thing and have been readin for about 2 hours now and I am still not sure what I should do or look for to see if anyone has previously modified the OMP...so if anyone has actually read this far into my first novel I would like to know...
Can I reconnect the lines by just pushing them back on the little cones or have they been ripped out of some kind of neato connector that I have never seen before?
If I can reconnect them. does it matter which line gets put back on which connector?
If it has been modified so it doesn't use the OMP anymore, what should I look for and where?
and last but not least......What exactly the hell does the OMP do?
A little about me and my car first...I have worked on everything from single cylinder motors to inline 24s, but this is my first foray into rotorys...I just got an 86 n/a that was constantly flooding on the guy and he didn't want to mess with it (just for the record when I popped the hood to look at the motor, he said," I ain't never seen nu'in like that afore.") he traded 2 fishing poles for it and I gave him $50...I figure if worse comes to worse...I know a junkyard that will give me $100 for it...but then I wouldn't be havin so much fun learnin new stuff
Anyways...I did the whole unflooding thing and got it to start and run until water started shooting out from between both sides of the waterpump housing so I shut it down and started to take the waterpump off to replace the gaskets...and thats when I noticed the funny lookin little thing with the 4 hoses going to it...or in my case...supposed to be going to it...
3 of the 4 hoses are off...and I say off bececause I don't mean disconected, I mean they are off...with the little cone shaped piece that looks like it goes inside the hose stickin up....
Now, I tried the search thing and have been readin for about 2 hours now and I am still not sure what I should do or look for to see if anyone has previously modified the OMP...so if anyone has actually read this far into my first novel I would like to know...
Can I reconnect the lines by just pushing them back on the little cones or have they been ripped out of some kind of neato connector that I have never seen before?
If I can reconnect them. does it matter which line gets put back on which connector?
If it has been modified so it doesn't use the OMP anymore, what should I look for and where?
and last but not least......What exactly the hell does the OMP do?
03-07-02, 06:23 PM
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Welcome to the forum!
I can't answer your repair question (I've never had an OMP prob so I've never looked that hard!) but you must get these repaired ASAP! The oil metering pump has two lines that feed oil into the intake runners and two thar inject oil directly into the housings. This is to lube the insides of the engine and is very important. Running without this will cause engine danage and premature failure. Hope you get this sorted and your car running soon!
I can't answer your repair question (I've never had an OMP prob so I've never looked that hard!) but you must get these repaired ASAP! The oil metering pump has two lines that feed oil into the intake runners and two thar inject oil directly into the housings. This is to lube the insides of the engine and is very important. Running without this will cause engine danage and premature failure. Hope you get this sorted and your car running soon!
03-07-02, 07:08 PM
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The hose are nylon or some polypropylene blend.  They are crimped on with metal crimps - I have no found a way to repair them easily.  They are brand new from the Mazda dealer for about $20 EACH.
Lack of oil metering will kill rotor housings.
-Ted
Lack of oil metering will kill rotor housings.
-Ted
03-07-02, 07:35 PM
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OK...Starting from the top. Congratulations of getting into the rotary experience. You are fortunate to have the sense to get on this forum right off the bat. Dummy me messed around for nearly a year before I stumbled across it.
The OMP (oil metering pump) is designed to inject a controlled amount of oil into the intake manifold and intake ports to lubricate the apex seals. The apex seals function like piston rings do in a reciprocating engine. These seals have no way of being lubricated like the rings in a piston engine do, so Mazda uses the OMP. The amount of oil being injected at any given time is dependant on the throttle position. You will see a rod going from the throttle body down to the OMP. This rod must not be bent or distorted in any way since that would affect the amount of oil being injected into the engine (this rod has bends in it from the factory for clearance, just don't bend it yourself).
The part you refer to is a vacuum spider. The spider has one larger line coming off it that goes to the front of the throttle body. The other side of the spider has four vacuum lines that run to each of the four injectors. I have never been able to determine for certain why the vacuum is needed, but Mazda put it there for a reason. Look at the OMP itself. You will see four translucent white colored lines coming off it and disappearing under the manifold runners. These lines hook up to each of the four oil injectors as well. Their purpose is to carry the metered amount of oil from the OMP to the injectors. These line become very brittle with age and are easy to break if you try to move or pull on them. They must be replaced if broken. You can't repair them.
These white oil lines are the ones Ted was referring to when he spoke of the 20 dollar price. The upper portion of the manifold (tube like structure) must be removed to get to the oil injectors to replace them. The vacuum lines going from the vacuum spider to the oil injectors are buried under there also.
To answer your question; these lines must be intact and functioning properly or your apex seals will not be lubricated. This will quickly ruin your engine. There is a way to get around the OMP though. Many of the members here run oil mixed in with the gasoline. You need to pour about one ounce of two stroke or Marvel Mystery oil into the tank for each gallon of gasoline. This way the lubricating oil for the apex seals is injected into the engine by the fuel injectors along with the gasoline. Kinda like a two stroke motorcycle engine works. By running this pre-mix all the time you can get rid of the OMP altogether. If you decide to do this you need to make sure you have the vacuum lines sealed so the engine does not have a vacuum leak. You can then disconnect the rod going from the throttle body to the OMP. The lines going from the OMP to the oil injectors may be left in place, but the vacuum lines connected to the oil injectors need to be plugged up. When using the pre-mix it is a good idea to pour the oil into the gas tank before pumping the gas in. This helps assure a good mixing of the oil and gas.
On the 86 models the OMP is purely mechanical and may be removed provided you fashion a metal plate to cover the OMP mount on the front engine cover. On the later model (88 and up I think) 13B engines the OMP is also electronic and will mess the computer up if it is removed from the engine.
The OMP (oil metering pump) is designed to inject a controlled amount of oil into the intake manifold and intake ports to lubricate the apex seals. The apex seals function like piston rings do in a reciprocating engine. These seals have no way of being lubricated like the rings in a piston engine do, so Mazda uses the OMP. The amount of oil being injected at any given time is dependant on the throttle position. You will see a rod going from the throttle body down to the OMP. This rod must not be bent or distorted in any way since that would affect the amount of oil being injected into the engine (this rod has bends in it from the factory for clearance, just don't bend it yourself).
The part you refer to is a vacuum spider. The spider has one larger line coming off it that goes to the front of the throttle body. The other side of the spider has four vacuum lines that run to each of the four injectors. I have never been able to determine for certain why the vacuum is needed, but Mazda put it there for a reason. Look at the OMP itself. You will see four translucent white colored lines coming off it and disappearing under the manifold runners. These lines hook up to each of the four oil injectors as well. Their purpose is to carry the metered amount of oil from the OMP to the injectors. These line become very brittle with age and are easy to break if you try to move or pull on them. They must be replaced if broken. You can't repair them.
These white oil lines are the ones Ted was referring to when he spoke of the 20 dollar price. The upper portion of the manifold (tube like structure) must be removed to get to the oil injectors to replace them. The vacuum lines going from the vacuum spider to the oil injectors are buried under there also.
To answer your question; these lines must be intact and functioning properly or your apex seals will not be lubricated. This will quickly ruin your engine. There is a way to get around the OMP though. Many of the members here run oil mixed in with the gasoline. You need to pour about one ounce of two stroke or Marvel Mystery oil into the tank for each gallon of gasoline. This way the lubricating oil for the apex seals is injected into the engine by the fuel injectors along with the gasoline. Kinda like a two stroke motorcycle engine works. By running this pre-mix all the time you can get rid of the OMP altogether. If you decide to do this you need to make sure you have the vacuum lines sealed so the engine does not have a vacuum leak. You can then disconnect the rod going from the throttle body to the OMP. The lines going from the OMP to the oil injectors may be left in place, but the vacuum lines connected to the oil injectors need to be plugged up. When using the pre-mix it is a good idea to pour the oil into the gas tank before pumping the gas in. This helps assure a good mixing of the oil and gas.
On the 86 models the OMP is purely mechanical and may be removed provided you fashion a metal plate to cover the OMP mount on the front engine cover. On the later model (88 and up I think) 13B engines the OMP is also electronic and will mess the computer up if it is removed from the engine.
03-07-02, 07:42 PM
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first fill your gas tank and put in 16 oz of 2 stroke engine oil. (in your gas tank)
well look at your gas gauge and figure out ~how many gallons are in there and then put in 1 oz per gallon.
it will now be safe to run your car as far as oil is concerned
check to see if oil is spurting out while running, (pull on the metal bar that is connected to the omp and throttle body to get more oil) if not then you must either fix your omp or get a new or rebuilt one (or used) if oil does squirt out then try to reconnect the hosses and if they go on then that is great, if they stay on while running even better,
if they dont go on (ends are broken) then you must either get new ones or block off your omp (ask ted) and run your car with 2 cycle. if they go on but dont stay you must try to get some sort of tiny clamps to hold it on (epoxy will work but ask ted about that one too)
Justin
well look at your gas gauge and figure out ~how many gallons are in there and then put in 1 oz per gallon.
it will now be safe to run your car as far as oil is concerned
check to see if oil is spurting out while running, (pull on the metal bar that is connected to the omp and throttle body to get more oil) if not then you must either fix your omp or get a new or rebuilt one (or used) if oil does squirt out then try to reconnect the hosses and if they go on then that is great, if they stay on while running even better,
if they dont go on (ends are broken) then you must either get new ones or block off your omp (ask ted) and run your car with 2 cycle. if they go on but dont stay you must try to get some sort of tiny clamps to hold it on (epoxy will work but ask ted about that one too)
Justin
03-07-02, 07:47 PM
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Originally posted by copandengr
The part you refer to is a vacuum spider. The spider has one larger line coming off it that goes to the front of the throttle body. The other side of the spider has four vacuum lines that run to each of the four injectors. I have never been able to determine for certain why the vacuum is needed, but Mazda put it there for a reason. Look at the OMP itself. You will see four translucent white colored lines coming off it and disappearing under the manifold runners. These lines hook up to each of the four oil injectors as well. Their purpose is to carry the metered amount of oil from the OMP to the injectors. These line become very brittle with age and are easy to break if you try to move or pull on them. They must be replaced if broken. You can't repair them.
The part you refer to is a vacuum spider. The spider has one larger line coming off it that goes to the front of the throttle body. The other side of the spider has four vacuum lines that run to each of the four injectors. I have never been able to determine for certain why the vacuum is needed, but Mazda put it there for a reason. Look at the OMP itself. You will see four translucent white colored lines coming off it and disappearing under the manifold runners. These lines hook up to each of the four oil injectors as well. Their purpose is to carry the metered amount of oil from the OMP to the injectors. These line become very brittle with age and are easy to break if you try to move or pull on them. They must be replaced if broken. You can't repair them.
Justin
03-07-02, 08:09 PM
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Justin;
He may be referring to the oil lines at the OMP but the way I read the post he is referring to the vacuum spider. The spider is also very prone to breaking with age. The oil lines do not have a "cone shaped thing that goes into the hose" so I took that to mean he was looking at the spider, plus the fact that the spider is behind the water pump and would be obviously visible when working in that area. At any rate there most certainly is vacuum hooked up to the oil injectors. Why I do not know.There is no positive air pressure on these lines on my NA. There is a vacuum there. Even Mazdatrix calls it a vacuum spider. That is not my name for it.
He may be referring to the oil lines at the OMP but the way I read the post he is referring to the vacuum spider. The spider is also very prone to breaking with age. The oil lines do not have a "cone shaped thing that goes into the hose" so I took that to mean he was looking at the spider, plus the fact that the spider is behind the water pump and would be obviously visible when working in that area. At any rate there most certainly is vacuum hooked up to the oil injectors. Why I do not know.There is no positive air pressure on these lines on my NA. There is a vacuum there. Even Mazdatrix calls it a vacuum spider. That is not my name for it.
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03-07-02, 08:09 PM
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Thanks for the welcomes and the advice...
I'd hate to have blown out the motor when I have 2stroke oil sitting in my garage (I'm a bit of a motorcycle guy too) so now I can run the engine without worrying after I get the water pump on....
There is a junkyard here that has 3 86 RX-7s in it and they are mostly complete so hopefully I can get a full set of the hoses without havin to pay $20 a piece...I plan on using as much junkyard stuff as possible to get it running before I decide whether or not I want to spend serious money on another playtoy...
I saw a lot of pics of really nice cars in the gallery...You think they would post a pic of my $50 rolling wreck?
I'd hate to have blown out the motor when I have 2stroke oil sitting in my garage (I'm a bit of a motorcycle guy too) so now I can run the engine without worrying after I get the water pump on....
There is a junkyard here that has 3 86 RX-7s in it and they are mostly complete so hopefully I can get a full set of the hoses without havin to pay $20 a piece...I plan on using as much junkyard stuff as possible to get it running before I decide whether or not I want to spend serious money on another playtoy...
I saw a lot of pics of really nice cars in the gallery...You think they would post a pic of my $50 rolling wreck?
03-07-02, 08:13 PM
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cop......I was refering to oil lines at the OMP...I have...uh...HAD no idea what was on the other of those lines....at this point too much information is not enough so I thank you wholeheartedly for your reply...
You too RX7Impreza....
You too RX7Impreza....
Last edited by QuantumDuck; 03-07-02 at 08:16 PM.
03-07-02, 11:19 PM
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on the issue of the vacuum lines,
i dont want to really get into another argument online so dont take this as a "no, your wrong ******* reply" just wanna clear it up. you are right about them being vacuum lines, but i see no purpose in haveing vacuum there so i assume that they spray the oil in. i have never felt of a vaccum in these lines, have you???
Justin
i dont want to really get into another argument online so dont take this as a "no, your wrong ******* reply" just wanna clear it up. you are right about them being vacuum lines, but i see no purpose in haveing vacuum there so i assume that they spray the oil in. i have never felt of a vaccum in these lines, have you???
Justin
03-07-02, 11:25 PM
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on the issue of the vacuum lines,
i dont want to really get into another argument online so dont take this as a "no, your wrong ******* reply" just wanna clear it up. you are right about them being vacuum lines, but i see no purpose in haveing vacuum there so i assume that they spray the oil in. i have never felt of a vaccum in these lines, have you???
Justin
i dont want to really get into another argument online so dont take this as a "no, your wrong ******* reply" just wanna clear it up. you are right about them being vacuum lines, but i see no purpose in haveing vacuum there so i assume that they spray the oil in. i have never felt of a vaccum in these lines, have you???
Justin
03-08-02, 12:48 AM
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Jason:
Yes I feel a vacuum at the point where the larger hose connects to the throttle body. A quick peek at my factory manual for my 86NA shows the spider as part of the vacuum tube routing diagram.
On a normally aspirated engine there is no positive pressure in the throttle body. I have posed the question on this forum before if anyone knew what the vacuum lines were for. What the lines may be is a weaker vacuum than is present at the oil injectors so the manifold vacuum will "suck" oil from the injectors. Other than that possibility I can't imagine what they are for.
Yes I feel a vacuum at the point where the larger hose connects to the throttle body. A quick peek at my factory manual for my 86NA shows the spider as part of the vacuum tube routing diagram.
On a normally aspirated engine there is no positive pressure in the throttle body. I have posed the question on this forum before if anyone knew what the vacuum lines were for. What the lines may be is a weaker vacuum than is present at the oil injectors so the manifold vacuum will "suck" oil from the injectors. Other than that possibility I can't imagine what they are for.
03-09-02, 01:56 AM
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Oh, the old "vacuum line" hose discussion rears its ugly head again! I know they are labelled "vacuum" lines and they are part of the vacuum system, but the large pipe going to the spider actually feeds from a passage in front of the throttle plates. Thus, there should at no time be a vacuum on this line. What is the purpose of the line, you ask? This line supplies clean (filtered) air to the oil injectors. When there is a vacuum on the engine side of the oil injectors, air is supplied to the injectors so that excess oil is not sucked into the engine through the oil injectors, only the metered amount of oil is supplied. This is from the Mazda service tech. manual. If I noted a vacuum at this port feeding the spider, I would be concerned and would troubleshoot it immediately - that means that there is an intake restriction somewhere between the air filter (could be the air filter itself) and the throttle plates, and that would decrease performance quite a bit, especially if it exists at idle or low rpm! Just my 2 cents worth! 
Irv, Keith's dad
Irv, Keith's dad
03-09-02, 03:15 AM
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Thank you for your reply, Irv. The question of these lines has been trying my pea brain for some time now. I am glad to hear from someone what they are for.
By the way...Where did you get access to the tech's manual you are referring to..I would love to get my hands on one. The factory service manual is a good one, but unlike many other factory manuals I have it does not explain why something is doing what it is. Most other factory manuals will give an explaination of the systems and what they do. The rex manual merely gives test methods and removal/installation/overhaul data. It does not give theory.
By the way...Where did you get access to the tech's manual you are referring to..I would love to get my hands on one. The factory service manual is a good one, but unlike many other factory manuals I have it does not explain why something is doing what it is. Most other factory manuals will give an explaination of the systems and what they do. The rex manual merely gives test methods and removal/installation/overhaul data. It does not give theory.
03-09-02, 03:51 AM
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On a 86-88, of the three *vac* hose that come out of the front of the throttle body, only the bottom one has a vacuum coming FROM the throttle body. The top two are just filtered air coming from the front of the throttle plates. The big one feeds air to the spider for the oil injectors, the next one feeds filtered air to the primary fuel injector air bleeds. There is a free service manual at the following url: http://www.iluvmyrx7.com/Technical_I...ice_manual.htm and there is a jpg at the bottom of the page. I didn't read very care fully everything on this post. I'm curious why, with the engine running you did not mention oil dripping from the ports on the oil metering pump. Did you have any oil dripping?????????????????????????
Last edited by HAILERS; 03-09-02 at 03:55 AM.
03-09-02, 04:04 AM
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Here's a couple of jpg that more than less, show how to checkout the function of the oil metering pump. I'm doing this to show you that if you download the manual from http://www.iluvmyrx7.com/Technical_I...ice_manual.htm you'll see that the book is useful. It does not go into detail how everything works, but is helpful. EDIT: It just occured to me, the front two lines go to the oil injectors on the rotor housings, and the aft two go to the injectors on the intake manifold. Personaly I don't think it matters which goes where. A drip is a drip is a drip. Could be wrong about that.
Last edited by HAILERS; 03-09-02 at 04:18 AM.
03-09-02, 04:08 AM
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The second jpg to go with the one above: and I'm not real clear if the guy who donated the car to you didn't get the better deal. It all depends on the quality of the rods and reels. Some of that stuff is high tech with the high price to go with it (humor).
Last edited by HAILERS; 03-09-02 at 04:12 AM.
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