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RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.

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Old 01-17-2011, 01:04 PM   #1
sv51macross
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Default Oil injectors, aux port actuation

Tired of putting oil in the gas at each fillup. Recently replaced the oil injection lines and after a week realized that the leading housing injector line wasn't drawing oil. Now that I have the UIM off, I see that the leading manifold injector stopped drawing oil halfway so the oil in the line stops 5" from the injector.

Would rather not have to wait/pay for new injectors, can I clean them with reasonable effort if they are clogged? (May be clogged, little/no oil passed through them for the last few years on account of my inexperience with Mazda Wankels and the previous owner being a ****).

Also, my aux ports won't work. The sleeves and actuators are free, but won't work. They worked before I had the intake tract off, now the aux ports won't open. Any suggestions? All the lines were snug on their nipples.

Unrelated, can I ground the manifold off one of the heatshield nuts? I would love not having to take off the LIM/heatshield to reground my O2 sensor.






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Last edited by sv51macross; 01-17-2011 at 01:17 PM..
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Old 01-18-2011, 10:49 PM   #2
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The aux ports only activate if you have a functional air pump. If you do, the ACV (air control valve) also has to work. The solenoids for the 6PI and VDI can be tested, as can the actuators. Don't forget that you have to be driving the car to get the 6PI or VDI to activate - sitting in the driveway is not enough. A lot of people use grease or petroleum jelly to determine if the 6pi is operating.

The oil metering injectors should be easily cleaned by a spray can and pipe cleaner.

The OMP injects oil very slowly, so it is possible that the oil has not reached the injector yet. You also should have the vacuum lines connected correctly on the tops of the injectors.

You can ground the exhaust manifold anywhere on the manifold. I don't know if the heat shield is a good spot (My cars have all 'lost' their heat shields) but you could certainly use the manifold to downpipe connection bolts to put a ground wire under.
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Old 01-19-2011, 01:03 AM   #3
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Quote:
Originally Posted by NoDOHC View Post
The aux ports only activate if you have a functional air pump. If you do, the ACV (air control valve) also has to work. The solenoids for the 6PI and VDI can be tested, as can the actuators. Don't forget that you have to be driving the car to get the 6PI or VDI to activate - sitting in the driveway is not enough. A lot of people use grease or petroleum jelly to determine if the 6pi is operating.

The oil metering injectors should be easily cleaned by a spray can and pipe cleaner.

The OMP injects oil very slowly, so it is possible that the oil has not reached the injector yet. You also should have the vacuum lines connected correctly on the tops of the injectors.

You can ground the exhaust manifold anywhere on the manifold. I don't know if the heat shield is a good spot (My cars have all 'lost' their heat shields) but you could certainly use the manifold to downpipe connection bolts to put a ground wire under.
I replaced the OMP lines over Thanksgiving break. It shouldn't take that long, and the back trailing rotor injection lines are filling just fine.

I fully intend on emptying the rest of my current ban of brake cleaner into the injectors if it can unclog/restore them. Vacuum supply was good, but to be safe all the vac lines are getting a dab of black RTV on the nipples.

I didn't realize that the aux ports needed the car to be moving. In retrospect...makes sense.
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Old 01-19-2011, 09:56 PM   #4
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Update:

Was able to do a bit more disassembly. Found that the exhaust manifold nuts were above the heatshield...after breaking the heads off the top two bolts. At least I can now ground it proper and get some fuel economy back!

-That aside I removed both manifold injectors and spritzed some brake cleaner through the vac nipple, injector orifice, and the banjo bolt orifices. Did the blow/suck test and one I could both blow and suck through the vac nipple, the other would blow through and allow a little air to suck through. Haven't tested the housing injectors, but it seems that only one of the four injectors is actually working.
-Now, could it be a loss of vacuum? Perhaps the hose that plugs into the intake snorkel isn't sealing? Or do I have three bad injectors? (If the latter, then f***-it, I'm buying a container to pemix 2-stroke oil until I rebuild/swap the engine).
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Old 01-20-2011, 01:34 PM   #5
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Quote:
Originally Posted by sv51macross View Post
Update:

-That aside I removed both manifold injectors and spritzed some brake cleaner through the vac nipple, injector orifice, and the banjo bolt orifices. Did the blow/suck test and one I could both blow and suck through the vac nipple, the other would blow through and allow a little air to suck through. Haven't tested the housing injectors, but it seems that only one of the four injectors is actually working.
^Interesting that you mention this. I've got my engine apart now for some other work, and since the oil injectors were easily accessable I pulled them all out and did the suck/blow test per the FSM (Ok wise guys, stop snickering!). My results were similar to yours - I could blow thru all of them, but when trying to suck a vacuum, only one truly passed the FSM test. To get more repeatable & measrable results, I repeated the suck test with my Mityvac vacuum pump on each of them and found that only 1 injector would HOLD a vacuum for at least a few minutes; all of the others would just start to build a vacuum, but then bled down to ambient pressure at various rates.
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Old 03-11-2011, 02:55 AM   #6
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Oil metering pumps and injectors don't work like it seems some think.

Read jpgs attached.

Oil does NOT go thru/past the rubber check valve at the top of the injector.

Blowing and sucking at one end or the other does not determine if the path of the oil is blocked inside the injector.

Vacuum is only seen at the BOTTOM of the injectors. The top gets what the attached jpg says..............bleed air like the bleed air for fuel injectors. Not vacuum, please.
Attached Images
File Type: jpg OILMETERINGPUMP.jpg (117.1 KB, 14 views)
File Type: jpg OILMETERINGPUMPTWO.jpg (98.3 KB, 11 views)
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Old 03-12-2011, 07:06 PM   #7
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Quote:
Originally Posted by FRED View Post
Oil metering pumps and injectors don't work like it seems some think.

Read jpgs attached.

Oil does NOT go thru/past the rubber check valve at the top of the injector.

Blowing and sucking at one end or the other does not determine if the path of the oil is blocked inside the injector.

Vacuum is only seen at the BOTTOM of the injectors. The top gets what the attached jpg says..............bleed air like the bleed air for fuel injectors. Not vacuum, please.
Read my post again, I didn't say anywhere that oil is supposed to go thru/past the check valve within the injector, or imply that vacuum is used by the system in the way you seem to think I did. I realize that "vacuum" hose connects to a fresh air port before the throttle plates. I was simply relaying my test results.

Obviously the FSM suck/blow test procedure for OMP injectors is designed to check the functionality of the check valve within. For the "suck" portion of the test, I simply modified the procedure by using a vacuum pump & hose. Most vacuum pumps also have a pressure port, so you can use them for the "blow" portion of the test too. This has a few benefits - (1) You don't have to put your lips on a filthy oil injector, (2) The hose makes a better seal on the tiny injector nipple than your lips do, and (3) The test is repeatable, and it produces quantitative results (i.e., numbers on a vac/pressure gauge).
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Old 03-12-2011, 07:38 PM   #8
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only brand new oil injectors seem to pass the test, doesn't mean that they still aren't functioning but maybe not ideally. generally about 70-80% seem to fail it.
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