My Evo IX, Scared of loud noises & Vibrations

Subscribe
Mar 19, 2010 | 12:34 PM
  #1  
Yeah, Weird but I noticed it when I was at the drag`s and an open header V8 warmed up it tires. Also when a Harley davidson is reving his engine next to me at red light. Once I also took a Ferry across a river and the vibrations made it react

My car drops RPM to low 500`s or lower and oil Pressure drops to 10psi or lower and Oil light in dash goes on... I have to rev my engine in order to make it stop, Never stalled on me yet but very close

Anyone ever have this problem ? or ideas why it would do this ?

Any input is appreciated

Thanks
Reply 0
Mar 19, 2010 | 12:35 PM
  #2  
We have very sensitive MAF's --- it's normal!
Reply 0
Mar 19, 2010 | 12:40 PM
  #3  
Go Speed Density and you'll never have to worry again.
Reply 0
Mar 19, 2010 | 12:44 PM
  #4  
Yep, I've got a problem like that, but it's a little hit and miss. The exact issue that I have right now only happens when the car is idling. I've checked my map and see that idle RPM goes from 797 to over 1k for extreme cold conditions, so it's not like it was tuned too low to be cut off if a hiccup happens.

Anyways, often times at idle my RPM's will drop from ~850-900 to ~700/500, and sometimes even close to cutoff(!) at ~350. Issue only happens when the car is warmed up, never during the initial warmup. Almost every time the ECU realizes what happened and picks the RPMs back up to normal idle RPM, but sometimes I have to give it a little gas to pick it up, or it (I've never let go on for more than a few seconds) might end up just staying low. This issue happens with and without lights/ac/heat, in all the temperatures that a typical southernish Norcal car would experience (generally 40 to 110).

It happened only rarely after I installed the Injen LICP/UICP/Intake.

It is still an issue after my car was tuned, but I think that if the tuner is aware of the problem, he might be able to tune it out. I'm going to get my car retuned soon and will ask about checking this issue out and seeing if it's easily tuned through- if not, then Speed Density may come in.
Reply 0
Mar 19, 2010 | 01:02 PM
  #5  
So from what im reading its normal right ?
Reply 0
Mar 19, 2010 | 01:04 PM
  #6  
Yeah its normal.
Reply 0
Mar 19, 2010 | 01:12 PM
  #7  
yes, healthy v-8's or open pipe harley Davidsons will disrupt the MAF. Not much you can do about it. I just leave car off until I need to line up.
Reply 0
Mar 19, 2010 | 08:13 PM
  #8  
My guess would be the knock sensor being set off by the noise or vibration. Still normal unless the sensor is too sensitive.
Reply 0
Mar 19, 2010 | 08:26 PM
  #9  
Quote: My guess would be the knock sensor being set off by the noise or vibration. Still normal unless the sensor is too sensitive.

This is the CORRECT answer!!
Reply 0
Mar 20, 2010 | 12:24 AM
  #10  
At first I thought the OP was kidding, but damn I just learned something!!
Reply 0
Mar 20, 2010 | 12:29 AM
  #11  
I dont see how this would be related to the MAF but hey what do I know im just a noob. The first thing that came to my mind was the knock sensor...
Reply 0
Mar 21, 2010 | 08:02 AM
  #12  
So how do I convert from MAF to Speed Density... what do I need ?
Reply 0
Mar 21, 2010 | 08:13 AM
  #13  
Wow - I noticed this too on my IX ... I thought I was imagining things until I read this thread! - Harleys do it to my car.
Reply 0
Mar 21, 2010 | 08:14 AM
  #14  
it is more and likely your knock sensor. i've noticed that my car will drop in rpms when its warm and i close the hood. the noise makes the car drop in rpms and my guess is the knock sensor feeling the vib/noise and thinking it was produced by the motor. never had a harley do that to me yet but i have noticed the hood thing. didnt really think the maf would be the cause of this. i might just log this and see if by closing the hood causes knock. we'll see
Reply 0
Mar 21, 2010 | 08:20 AM
  #15  
+1 On Speed Density, tuners are making good power on it too.
Reply 0