Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-08-2010, 02:38 PM   #1 (permalink)
eco....something or other
 
Join Date: Jul 2009
Location: Colfax, WI
Posts: 719

wood hauler - '91 Ford F-250
Team Pontiac
90 day: 18.97 mpg (US)

Rav - '06 Toyota Rav4 Base
90 day: 26.52 mpg (US)
Thanks: 39
Thanked 61 Times in 46 Posts
running lean, code 172, and vacuum leak

The vacuum leak is in the back of the EGR valve. The valve stem is leaking on the fresh air side. Is this why my mileage is so good? If I replace the EGR valve will my mileage go down? I don't think it is dangerously lean, just enough so the 02 sensor doesn't switch a lot. I remember a thread a while back about unmetered air...guess now I get to experiment.

__________________



1991 F-250:
4.9L, Mazda 5 speed, 4.10 10.25" rear
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-08-2010, 02:58 PM   #2 (permalink)
eco....something or other
 
Join Date: Jul 2009
Location: Colfax, WI
Posts: 719

wood hauler - '91 Ford F-250
Team Pontiac
90 day: 18.97 mpg (US)

Rav - '06 Toyota Rav4 Base
90 day: 26.52 mpg (US)
Thanks: 39
Thanked 61 Times in 46 Posts
never mind the replacement.....$90! I am not going to be buying a replacement.
__________________



1991 F-250:
4.9L, Mazda 5 speed, 4.10 10.25" rear
  Reply With Quote
Old 07-08-2010, 03:55 PM   #3 (permalink)
EcoModding Apprentice
 
Dr. Jerryrigger's Avatar
 
Join Date: Jun 2010
Location: mass
Posts: 181

The Sh*t-Box - '99 Subaru Impreza Outback Sport
90 day: 27.81 mpg (US)
Thanks: 4
Thanked 9 Times in 8 Posts
electrical tape?
  Reply With Quote
Old 07-08-2010, 10:22 PM   #4 (permalink)
Master EcoModder
 
Join Date: Dec 2008
Location: South Jersey
Posts: 553

Little Blue - '98 Ford Escort ZX2 Cool
Team ZX2
90 day: 44.75 mpg (US)

Big Red - '00 Ford Excursion XLT
90 day: 15.53 mpg (US)
Thanks: 5
Thanked 45 Times in 29 Posts
I'm the Unmettered Air Leak Guy

I eventually got a Wideband and it showed the AFR was still 14.7:1, so it was determined that the PCM believed the engine was running at a lower load that it actually was and therefore was advancing the ignition timing a little. You may be expieriencing the saming thing...
__________________
  Reply With Quote
Old 07-09-2010, 12:26 AM   #5 (permalink)
eco....something or other
 
Join Date: Jul 2009
Location: Colfax, WI
Posts: 719

wood hauler - '91 Ford F-250
Team Pontiac
90 day: 18.97 mpg (US)

Rav - '06 Toyota Rav4 Base
90 day: 26.52 mpg (US)
Thanks: 39
Thanked 61 Times in 46 Posts
So this is good? I might want to turn my timing back to 10-12° instead of 14°?
__________________



1991 F-250:
4.9L, Mazda 5 speed, 4.10 10.25" rear
  Reply With Quote
Old 07-09-2010, 10:59 PM   #6 (permalink)
Master EcoModder
 
Join Date: Dec 2008
Location: South Jersey
Posts: 553

Little Blue - '98 Ford Escort ZX2 Cool
Team ZX2
90 day: 44.75 mpg (US)

Big Red - '00 Ford Excursion XLT
90 day: 15.53 mpg (US)
Thanks: 5
Thanked 45 Times in 29 Posts
I'd just leave it the same if it's working and you don't detect any issues. You'd only be changing the base timing by moving the distributor, I don't believe it will help by moving the base timing back, you might want to play with the base timing to see it's effect on mpg's....
__________________
  Reply With Quote
Old 07-10-2010, 12:24 AM   #7 (permalink)
eco....something or other
 
Join Date: Jul 2009
Location: Colfax, WI
Posts: 719

wood hauler - '91 Ford F-250
Team Pontiac
90 day: 18.97 mpg (US)

Rav - '06 Toyota Rav4 Base
90 day: 26.52 mpg (US)
Thanks: 39
Thanked 61 Times in 46 Posts
I moved it from 10° to 14° a while back to increase low end torque but I did other mods at the same time so it is hard to tell what I accomplished mpg wise with the timing. I will try turning it back a little and see what happens.

__________________



1991 F-250:
4.9L, Mazda 5 speed, 4.10 10.25" rear
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com