PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Low on gas -> computer pulls timing ???

Thread Tools
 
Search this Thread
 
Old 09-22-2003, 12:07 PM
  #1  
TECH Apprentice
Thread Starter
 
Iv_z28's Avatar
 
Join Date: Jul 2002
Location: Tucson, AZ
Posts: 393
Likes: 0
Received 0 Likes on 0 Posts
Default Low on gas -> computer pulls timing ???

Somebody posted in another thread:

>Oh and one more thing, did you have a full tank of gas? If
>you were low on gas, the computer pulls timing. Just a
>thought.
>--------------------
>Gev

Is this really true??? I seriosly doubt that, but just want to hear from somebody familiar with the subject. I don't think I ever notice any difference at the track..
Old 09-22-2003, 12:28 PM
  #2  
7 Second Club
iTrader: (7)
 
NicD's Avatar
 
Join Date: Nov 2001
Location: Chandler, AZ
Posts: 2,807
Received 332 Likes on 223 Posts
LS1Tech 20 Year Member
Default Re: Low on gas -> computer pulls timing ???

Not that I have seen, all the way down to E doesn't pull timing.
Old 09-22-2003, 12:35 PM
  #3  
TECH Senior Member
 
Colonel's Avatar
 
Join Date: Nov 2001
Location: Troy, AL
Posts: 9,246
Likes: 0
Received 2 Likes on 2 Posts

Default Re: Low on gas -> computer pulls timing ???

No. This misconception comes from people realizing increased performance after a fillup. This is because when you fill up, the PCM reverts back to the high octane table if it had previously gone to the low octane table. So, IF you've been getting enough KR to force it into low octane mode, the power will be temporarily restored after a fillup (until whatever caused it to go into low octane mode happens again.)
Old 09-22-2003, 05:21 PM
  #4  
TECH Enthusiast
 
WS6 GreeN's Avatar
 
Join Date: Jan 2003
Location: Birmingham, AL
Posts: 582
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Low on gas -> computer pulls timing ???

Is there something you can monitor in ATAP to check which table you're using?
Old 09-22-2003, 06:46 PM
  #5  
TECH Senior Member
 
Colonel's Avatar
 
Join Date: Nov 2001
Location: Troy, AL
Posts: 9,246
Likes: 0
Received 2 Likes on 2 Posts

Default Re: Low on gas -> computer pulls timing ???

If you're noticing more than slight KR at any point, then it's a safe bet that you're in the low octane mode. You can monitor your timing advance with Autotap. If you're seeing low numbers at high RPM and KR then you know you have a problem.
Old 09-22-2003, 10:50 PM
  #6  
TECH Fanatic
iTrader: (9)
 
Josh's Avatar
 
Join Date: Feb 2002
Location: West Lafayette, IN
Posts: 1,061
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Low on gas -> computer pulls timing ???

Is the low octane table always used when the tank gets low? If so, when does the switch from the high octane table to the low octane table take place?

Thanks,
Josh
Old 09-22-2003, 11:00 PM
  #7  
TECH Senior Member
 
horist's Avatar
 
Join Date: Nov 2001
Location: Lake Zurich, IL
Posts: 7,036
Likes: 0
Received 1 Like on 1 Post

Default Re: Low on gas -> computer pulls timing ???

NO.. low octane table is ONLY used when computer senses something's up... if it sees consistent KR or if it senses a problem w/the knock sensors... it will go into the low octane tables ...

The gas level does not affect it going into the low octane mode... I'm not sure how this rumour got started but whomever started it should be stoned cause it's far from the truth... if you don't believe me.. drive your car down to very little gas and watch your atap logs.. low octane tables are VERY noticable....
Old 09-25-2003, 08:31 AM
  #8  
TECH Apprentice
 
WS6 RULES's Avatar
 
Join Date: Sep 2002
Location: west coast
Posts: 366
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Low on gas -> computer pulls timing ???

And one more thing, when you pull timing your milage goes down, so why would it do that when your low on gas? Like he said, someone gave you bad info.




All times are GMT -5. The time now is 05:34 AM.