Go Back  Miata Turbo Forum - Boost cars, acquire cats. > Performance & Tuning > ECUs and Tuning > Hydra
Reload this Page >

Revs oscillating-- feeling nauseous, could use help :(

Hydra
Sponsored by:
Sponsored by:

Revs oscillating-- feeling nauseous, could use help :(

 
Old 04-05-2009, 02:49 AM
  #1  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,676
Total Cats: 120
Default Revs oscillating-- feeling nauseous, could use help :(

I have a hydra 2.5 and I recently upgraded my fuel pump a few months ago . I re-autotuned properly (or so I thought) but now 6 weeks later, somewhat coincidentally with the warmer weather I've been getting oscillations in my revs.

When I'm in boost or anywhere above -10 vacuum there's no oscillations. I get oscillations throughout the rev range whenever I'm betweeen -25 and -10. It's about 2 oscillations a second and I can hear it, feel it, and watch my boost gauge needle bouncing around.

Anyone have any ideas of what might be causing this?
Faeflora is offline  
Old 04-06-2009, 09:40 PM
  #2  
Senior Member
iTrader: (4)
 
Join Date: Aug 2007
Location: Omaha, NE
Posts: 618
Total Cats: 0
Default

I used to have this as well. Check your vacuum setting. When the car is idling, check your vacuum level (~500 in Hg). Set the value about 50 higher than what your idle setting is. I have to change mine every time the weather changes.
posidon42 is offline  
Old 04-09-2009, 06:49 AM
  #3  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,676
Total Cats: 120
Default

Do you mean the ISC setting?
Faeflora is offline  
Old 04-14-2009, 07:58 AM
  #4  
Senior Member
iTrader: (4)
 
Join Date: Aug 2007
Location: Omaha, NE
Posts: 618
Total Cats: 0
Default

That sounds about right. I am going to hook up the laptop tonight as I need to adjust some values after moving.
posidon42 is offline  
Old 04-14-2009, 08:21 AM
  #5  
Elite Member
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,851
Total Cats: 71
Default

Mine does this between 600 and 1200 rpm (slowly) sometimes when it's cool..and it either takes a minute to go away or a quick tap of throttle. It also happens when the car is warmed up when I turn the A/C on.
Doppelgänger is offline  
Old 04-15-2009, 10:26 AM
  #6  
Former Vendor
 
Join Date: Feb 2008
Posts: 128
Total Cats: 2
Default

Could be from being lean, or from trying to advance the VVT before you have sufficient oil pressure. Those are both easy things to check / fix.
usd2bfst is offline  
Old 05-13-2009, 12:44 PM
  #7  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,676
Total Cats: 120
Default

OK it was caused by being lean. I started over with a fresh base map from Jeremy and it was ok. Then I autotuned and it leaned it way out and now it does it again. I guess my wideband sensor is dying.
Faeflora is offline  
Old 05-13-2009, 07:54 PM
  #8  
Senior Member
 
airbrush1's Avatar
 
Join Date: Nov 2005
Location: Baltimore Maryland
Posts: 1,035
Total Cats: 8
Default

Interesing. My car does this when I first start it.... and it stops when It's warmed up. I have some settings to change
airbrush1 is offline  
Old 05-13-2009, 11:45 PM
  #9  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,676
Total Cats: 120
Default

It could be the cold start enrichment? Maybe it's not enriching enough?

BTW it may be worth contacting Jeremy and asking him to update your map. I sent him mine and there's quite a few changes on the new version. I think he has VVT programmed in properly too on the new map.
Faeflora is offline  
Old 05-14-2009, 08:46 PM
  #10  
Senior Member
 
airbrush1's Avatar
 
Join Date: Nov 2005
Location: Baltimore Maryland
Posts: 1,035
Total Cats: 8
Default

I got new cold start numbers from him. I have yet to load them however.
airbrush1 is offline  
Old 05-19-2009, 11:03 AM
  #11  
Newb
 
Join Date: Dec 2007
Posts: 16
Total Cats: 0
Default

I got an email from Jeremy yesterday stating he had worked through some cold start issues. Sent him my map for updates as well.
darbyfam is offline  
Old 06-09-2009, 10:33 AM
  #12  
Elite Member
Thread Starter
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,676
Total Cats: 120
Default

To update this thread for anyone searching for information--

This was caused by me running lean. My wideband had slowly died. I loaded up the base map which is far richer than my tune and all was well.

I think Long Term Trim might take input from the wideband so if your wideband dies (the hydra wideband dies slowly and reads increasingly inaccurately) it might screw up your table over time.
Faeflora is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bigmackloud
Miata parts for sale/trade
16
03-03-2019 03:41 PM
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM
tazswing
Race Prep
20
10-03-2015 11:04 AM
JesseTheNoob
DIY Turbo Discussion
15
09-30-2015 02:44 PM
ihiryu
General Miata Chat
9
09-28-2015 10:22 AM


Thread Tools
Search this Thread
Quick Reply: Revs oscillating-- feeling nauseous, could use help :(


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.