OC94Rx7

I am looking for information regarding the 2 oil injectors which are located on top of the rotor housing and have vacuum hose attached to them.

Information regarding.....
1) Construction?
2) Description of how they operate and function?
3) Signs of them failing to operate correctly?
4) Are they some kind of check- valves - like mechanism?
5) Are they constantly under vacuum?

I have been chasing a strange sound for sometime now. The sound is coming from 2 vacuum hoses which lead to the oil injector hoses on top of the rotor housing. (Please see photo attachment below)
When my water temps reach 95c a high pitch sqealing sound starts. When the water temps drop to 88c. The sound stops. I have found if I pinch the Yellow vac hose or the Red vac hose. The sound will stop while the water temps are at 95c. If the temps are under 95c and I pinch the Yellow and Red vacuum hoses the sound will start then fade away when I let go.

Here is some of the info I have found searching and asking forum members. The oil injector (valves??) prevent the oil from leaking into the rotor chambers when the motor is not running. Max Cooper has been very helpful off the forum. Suspecting the oil injector may be dirty or simply a slightly faulty mechically in some way that it only becomes a problem when temps rise and the metel injector exspands from the heat. Staying open enough to operate but when the air from the combustion chamber pushes out the (valve?) it then makes the sound which can be heard thru the vacuum hose. Also a different forum member said the vacuum hoses make the OMP (oil metering pump) increase or decrease the flow of oil to the rotor chamber. Do I have a bad OMP? or just the oil injector (valves??) connected to the vacuum hoses??

Appreciate any information or help in solving my problem.



Thanks
//Oliver

OC94Rx7

I made one statement incorrectly.

When the temps are under 95c and I pinch either the Red or Yellow hose. There is no sound until I let go, the sound will start but then quickly fade away again.

duboisr

The injector must have vacuum pulled on it before the oil can go through . The steady vacuum supply is from the pri turbo air intake elbow . The amount of oil is the ecu telling the omp what to do .Pull the injectors and clean, inspect them . Maybe try a set from another car that took them out and premixes .

rotorbrain

id say faulty. . . youve pretty much answered your own question. try another set. . . i may have another set around here. ill hunt for them.

paul

rotorbrain

youve intrigued me. . . i believe i have 2nd gen tII injectors. i wonder if the jets are a different size. . . since they have 4 lines instead of 2. i wonder if im getting enough oil. . . hmmmmmmmmmm.

i cant remember if the s5 tII engines have 2 or 4 injectors. i have s5s (i think) in my car. . . i guess i better check that out.

paul

OC94Rx7

Thanks for the reply and information. I will remove them and inspect them like you and Max have suggested.

I just found this thread on the single turbo section. I can see you were part of it. One interesting point was said at the end of the first page by GRZES21. He said that it can effect emissions too?

Again thanks

OC94Rx7

Here is the thread

https://www.rx7club.com/forum/showth...etering+nozzle

OC94Rx7

Thanks rotorbrain -

I am going to check mine first and also purchase new one just incase they are bad.

shawnk

What I took away from the above thread was that the hose should be hooked to a clean "atmosphere" source. Neither vacuum or boost made sense to operate that valve so the atomization explanation made the most sense. I havent gone back and rerouted mine yet but will as soon as my "to do" list gets shorter. When I do I am going to go to Advance Auto and buy one of those air filters and look like a K&N but are only about 1" in diameter and then I am going to hook both of my lines up to that.

Now for your problem - I am afraid it is much more complicated because you still have that rats nest. The noise is obviously caused by air moving across something but I wouldnt say it was the injectors first. How about if you unhook the lines from the injectors (leaving them open to atmosphere) and cap the lines? This will not hurt anything short term as there are people who have been running like this for a couple years with no noticeable ill affect. If the noise is still there then it would easy to tell where exactly it is coming from. It is either the injectors or a valve or a hose leak. The water temp relationship is interesting but I would not use it as info in the troubleshooting process. "Keep it simple" is my motto.

Sound like a good idea?


Shawn

OC94Rx7

Thanks Shawn for answering my pm and adding to this thread.

I was in a hurry today but I was able to unhook the Yellow vacuum hose at the end before it splits to the Red and Blue Vacuum hose. I did not cap any ends just left the end open to atmosphere.

It was VERY hot today. I drove about 10-15 minute and stop in a parking lot. I could hear the sound already at 88c. It seemed louder too. First time I have ever heard start under 95c . I pinched the Red hose and it stopped. I had to get home so I hooked up the vacuum hose again and drove home. When I got home I could still hear it but it was slightly quieter.

So, what to you think now?

I going to remove the manifold and all the rest of the **** so I can check the nozzles. Then go from there. Unfortunally it won't be this weekend.


Thanks again for your help everyone.

/Oliver

SleepR1

This is unrelated to the noise question OC94Rx7 posted, but could bad oil injectors cause oil to collect in my vacuum chamber? I'm pumping 80 to 300 mL of oil weekly out of my vacuum chamber in an effort to keep the vacuum chamber from completely filling with oil and screwing up my secondary turbo operation. I see that the oil injectors do get vacuum from the rat's nest. It seems to me that if the oil injectors were leaking wouldn't the oil from the rotor housings start being pulled through vacuum hoses, and into the vacuum lines? Is this possible?

Thanks in advance!

SPOautos

The nipple on the oil injectors is similar to a one way check valve. There are instructions in the workshop manual on how to check them. All you do is blow in them, I believe if you can blow thru them they are bad but if you can't they are good.....but its been a year or so since I looked it up so I could be off.

STEPHEN

SleepR1

The oil injectors look tough to get to...you have to tear down the intake stuff to get to the injectors. At least that's what it looks like to me. I have '93 manual, so I'll look up the procedure. Just wondered if oil in my vacuum chamber could be caused by leaking oil injectors...

OC94Rx7

Manny, It is a pain to get to the Metering oil nozzles with the vacuum lines attached on top. Like you said you have to remove everything. They are sitting on top of the Rotor housing (as you know). But, you could always check the larger vacuum hose (the yellow vac hose in my earlier attachment photo) that's spit's over to the smaller vac hose which run to the Oil nozzles. Remove the pressure chamber and the 2 solenoid valves ( WGC & TPC) and pop one of the vacuum hose ends off and take a look for oil.


Sorry I can't answer you question about the vacuum chamber oil issue. I had a track day in August and with my problem (noise issue) with the oil nozzle...I don't have any oil leaking in the vacuum hoses.

Hope you find the problem.

SleepR1

Thanks, I'll check out the yellow hose in your picture diagram!

OC94Rx7

here is a photo of my new nozzles... just arrived today.

SleepR1

Those look beefy. I can't imagine anything going wrong with those puppies.

OC94Rx7

Just an update for those who might have the same problem (down the road) as I did with the oil injectors.

I replaced the 2 oil injectors and also the 2 oil injector plastic pipe lines. With the car back together....the sound is gone!

//Oliver

SleepR1

I'm having mine replaced too