General Miata Chat A place to talk about anything Miata

Weird ass electrical beep/buzz

Thread Tools
 
Search this Thread
 
Old 10-01-2016, 12:19 AM
  #1  
Elite Member
Thread Starter
iTrader: (7)
 
jeff_man's Avatar
 
Join Date: May 2007
Location: Dallas, Tx
Posts: 3,006
Total Cats: 103
Default Weird *** electrical beep/buzz

I have no clue what is going on here. Someone smarter than me please help.

Video one I can unplug one of the coils and the beep/buzz stops. After a certain amount of time it stops. Then I realized it matches a wried *** thing the wideband is doing video two. Sorry didn't realize the alarm next door was drowning it out but you can still hear the beep/buzz.


jeff_man is offline  
Old 10-01-2016, 07:40 AM
  #2  
Elite Member
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,979
Total Cats: 356
Default

The AEM gauge does buzz a little, I can definitely hear on my quiet workbench, although I don't expect to be able to hear it in a car.

Does the engine bay noise stop if you disconnect the idle valve?
Reverant is offline  
Old 10-01-2016, 10:01 AM
  #3  
Elite Member
Thread Starter
iTrader: (7)
 
jeff_man's Avatar
 
Join Date: May 2007
Location: Dallas, Tx
Posts: 3,006
Total Cats: 103
Default

Originally Posted by Reverant
The AEM gauge does buzz a little, I can definitely hear on my quiet workbench, although I don't expect to be able to hear it in a car.

Does the engine bay noise stop if you disconnect the idle valve?
No idle valve
jeff_man is offline  
Old 10-03-2016, 03:58 PM
  #4  
Elite Member
 
x_25's Avatar
 
Join Date: Oct 2013
Location: NorthWest NJ
Posts: 1,821
Total Cats: 141
Default

The PWM heater for the AEM puts a **** ton of noise on the ground/power for the car. It is about 1A worth.

Your coil is ringing from that (coil of wire = electro magnet = speaker). My head unit did the same thing in mine. The actual head unit, with all the speakers disconected, would ring.

Connect a 2200uF (or bigger) 25V (or more) capacitor between the power and ground lines for the AEM. It should greatly lower the noise.
x_25 is offline  
Old 10-04-2016, 10:34 AM
  #5  
Elite Member
Thread Starter
iTrader: (7)
 
jeff_man's Avatar
 
Join Date: May 2007
Location: Dallas, Tx
Posts: 3,006
Total Cats: 103
Default

Originally Posted by x_25
The PWM heater for the AEM puts a **** ton of noise on the ground/power for the car. It is about 1A worth.

Your coil is ringing from that (coil of wire = electro magnet = speaker). My head unit did the same thing in mine. The actual head unit, with all the speakers disconected, would ring.

Connect a 2200uF (or bigger) 25V (or more) capacitor between the power and ground lines for the AEM. It should greatly lower the noise.
I found a missing ground wire that goes from the coil plug to the intake manifold. The tone is now barely audible and from what you said sounds like that's ok.
jeff_man is offline  
Old 10-04-2016, 10:38 AM
  #6  
Elite Member
 
x_25's Avatar
 
Join Date: Oct 2013
Location: NorthWest NJ
Posts: 1,821
Total Cats: 141
Default

Missing ground there would do it too. Although the AEM is still dumping ton's of noise. I would reccomend the cap anyway to make sure itndoesn't cause any problems with other sensors or whatnot.
x_25 is offline  
Old 10-04-2016, 10:56 AM
  #7  
Elite Member
Thread Starter
iTrader: (7)
 
jeff_man's Avatar
 
Join Date: May 2007
Location: Dallas, Tx
Posts: 3,006
Total Cats: 103
Default

Originally Posted by x_25
Missing ground there would do it too. Although the AEM is still dumping ton's of noise. I would reccomend the cap anyway to make sure itndoesn't cause any problems with other sensors or whatnot.
Thanks I will get 2 caps and install them.
jeff_man is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jpreston
Miata parts for sale/trade
1
10-03-2016 02:01 PM
88hk
General Miata Chat
4
09-29-2016 02:35 PM
Woogi
Engine Performance
7
09-28-2016 05:40 PM
jeff_man
MEGAsquirt
8
09-27-2016 10:00 AM
soospecmx5
WTB
0
09-01-2016 09:39 PM



Quick Reply: Weird ass electrical beep/buzz



All times are GMT -4. The time now is 07:56 PM.