My RX7 FD "MOO" sound from the Air Pump
 

Hey guys! I am a bit new to RX7!:)

I got the the problem of the "MOO" sound from the Air Pump while reving on idle! and in motion on 2nd gear and some times the 3rd gear, torque disappears after 4,500rpm or 5,000rpm! then that "MOO" comes out Loud when i leave the acceleration!

It's really annoying! I can't race anybody with this problem :'(, sometimes i get lucky when am on 3rd gear, the car pulls without the "MOO", and it flys, 4th & 5th!

On idle there's a click sound with a little "MOO" while reving! sound comes out from the Air Pump! I have the RE Amemiya Air Filter (New Blue Version), well i don't think it's from the Air Filter! because it even happened when the OEM Air Box!

Should i change the Air Pump? or disconnect it? and if i disconnect it is it okay? it says "NEVER REMOVE" on the pump! am a bit worried!:(

i posted a vid on youtube, /watch?v=sDr09W1ucDU

Pleeeeeeease Hepl :crying:

Search for it, there have been many threads describing this problem and solutions to fixing it.

I searched and i didn't get a clear picture!
my situation is little different, i loose power after 4,500rpm with a "MOO" after letting off!

check your rats nest man and search as said cos this has been covered several times. It's a common boost leak.

If I know what your problem is and I think I do, if your accelerating and after you hit 5k you let off and put your foot down again, it should make power like normal until redline (only try this in 3rd gear and up). Check for a break in the vacuum line and/or associated solenoid that goes to the big fat actuator under the turbo's.

FYI, that click in the video is normal when reving like that. It's the air pump shutting off and coming back on. Do not remove the air pump or your cat will fail pre-maturely. If you do not have a cat, then feel free to remove your air pump. ALSO, THE AIR PUMP IS NOT RELATED TO YOUR POWER LOSS PROBLEM AT ALL. Just wanted to make that clear :)

thewird

Hmmm, I have to have to the cat because of the passing test.
I thought it was related because that Loud "MOO" comes out when on the 2nd gear after the power disappears above 5,000rpm and sometimes 3rd gear, and when i let go after that, the MOOOOOOOOOOO comes out!
And it is known that the "MOO" is from the Air Pump!

Or what do ya say?

The moo you hear after letting off when you dont have power past 5k is not the air pump. Just because they both make moo sounds, doesn't mean they're coming from the same thing. I'm 100% sure your power loss problem is not from the air pump.

As was said check your vacuum lines and solenoids. But almost 99.9% its the vacuum line going to the big actuator under the turbo.

I've tuned a car before that had the exact same problem and spent time under the rats nest testing every line one by one. And since finding the problem, every time a car does this, it has always been that vacuum line.

thewird

Ahaaa... so my Air Pump is fine!!!:)
You're right, the boost leaking is definately from the vacuum lines! it's known!:nod:
I Shall check my vacuum lines and solenoids leading the actuator!

Thanks a lot for the help Man, you're the best!:icon_tup:

Just to be clear this actuator I'm talking about. Its what the #5 arrow is pointing too so check those 2 lines for leaks.

https://www.rx7club.com/attachment.p...1&d=1301478165

thewird

Now I get the picture!:)
Cool! Thanks a lot for clarification, i really needed this!
One question, Does my Actuator "probably" need to be replaced?

Possible but unlikely. Especially, if it works when your let off the gas and step on it again after 5k. It's most likelY the vacuum lines.

thewird

are you still running the factory rubber vacuum lines or have you upgraded to silicone? If you haven't, it is a good idea to switch to silicone.

Yes unfortunately i am still running on the factory rubber vacuum lines :(, but of course will switch to silicone.
Well i just got the car, it's been only 4 weeks since i was able to drive it, i imported it from the US last year with no engine, had to put an engine in it, and it's a JDM 1993 13B-REW, Paint it and changed some wear and tear parts.

If you notice in my video on youtube the sound of this rotary is way different, it sounds similar to the 20B! I don't know why?!:scratch:

If you notice in my video on youtube the sound of this rotary is way different than the others, it sounds similar to the 20B! I don't know why?! Do you?

Sounds like a normal stockish 13b to me, don't know where you got the 20b idea >_>. 20b sounds completely different. Since you just put the engine in, you most likely kinked that vacuum line when the engine was put in. I've seen it happen before more then once.

thewird

Im not sure if it is a vacuum line, i had the same noise when my air pump hose wasnt connected. as soon as i put it back on my airbox, it was gone. i believe you RE, i think it is your airpump making noises. you can clearly see/ hear in the video that when the noise is going on, the pulle on the pump is spinning.

The sound he is talking about is related to loosing power at past 5k becuase the 2nd turbo doesn't come on. After you let off it makes a boo sound but its not related to the air pump. The air pump moo is just a noise and doesn't affect anything other then you hearing it. The noises in the video are perfectly normal.

thewird

oh i see, i think i was just misunderstood lol.. my bad..

james

Yes Jamesrterra, I agree with you, for the Air Pump, it's not the vacuum line, thewird and me were talking about something else, we were talking about the boost leak, and i thought it was related to the Air Pump, but it appears no, i have to check my vacuum lines going to the Turbo Actuator like thewird said, i am going to check and see.

For the Air Pump noise, i don't know what is causing that annoying sound?:scratch:
What i read from others that it's the hose going to the Air Intake Filter! And by removing it the noise with go, but i can't remove it because it will damage my cat, if i had a straight pipe then it would be fine to remove it.

Anyway, the Air Pump doesn't concern me right now, i am just concerned about the Boost Leak from my vacuum lines going to the Turbo Actuator :(

I tried it once and it worked, but other times didn't work, even if i let go and press again still power is lost :(
Is it still the vacuum lines only or it's also the Actuator?

It's still the vacuum line don't worry...also it's worth to check the line that goes from the pressure chamber to the y-pipe...it can easily disconnect from the pressure chamber or the stock check valve may have failed...it happened to me once and i had the same mooo sound after release and power loss when the 2nd turbo should kick in.

That's the exact problem i have, do you have any diagram to make it clear for me please?:)

i will try to post something for you on sunday, a bit in a rush right now as im leaving and will travelling tomorrow all day

http://www.turborx7.com/images/Techn...e_diagram2.jpg

the one with the check valve that goes from the pressure chamber to the y-pipe....you'll have to take the pressure chamber off to see it....also make sure you didn't do what i did when i was putting my stuff back together one day and accidentally plug the other hose into the "empty pipe....that'll vent your pressure chamber real quick...*doh!*

Got the picture!
Thanks a lot man, i should check the the Actuator lines and the Pressure Chamber lines.