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c&l sample tube

  • Thread starter Thread starter Shirley
  • Start date Start date Jul 26, 2007
S

Shirley

Founding Member
Nov 14, 2001
112
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0
Phoenix, AZ
Jul 26, 2007
#1
  • Jul 26, 2007
  • #1
If a 24# sample tube was installed in the MAF, but the engine had 19# injectors, what would that do? Would it cause a code 41 or 91 to show up?
 

BK_CAULEY

it's built for speed not longevity, woman
Dec 26, 2006
0
10
49
Thomasville, ga
Jul 27, 2007
#2
  • Jul 27, 2007
  • #2
im not sure about the codes but im sure its telling your computer you are getting more air than you actually are and causing it to deliver more fuel.
 

gerzen

New Member
Jan 16, 2006
71
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Chihuahua México
Jul 27, 2007
#3
  • Jul 27, 2007
  • #3
yea you could get thoses codes because that means a lean condition, thast because the sample tube is calibrated to fool the ECU so that sample makes that the ECU pulse a little less the injectors for compensate the more fuel delivery in the 24 lbs injector but because you have a 19 lbs then you are going to have a less gasoline that you need, get a sample tube for use whit 19 lbs and you are set
 
S

superspec

Member
Aug 14, 2006
78
1
6
Jul 27, 2007
#4
  • Jul 27, 2007
  • #4
gerzen said:
yea you could get thoses codes because that means a lean condition, thast because the sample tube is calibrated to fool the ECU so that sample makes that the ECU pulse a little less the injectors for compensate the more fuel delivery in the 24 lbs injector but because you have a 19 lbs then you are going to have a less gasoline that you need, get a sample tube for use whit 19 lbs and you are set
Click to expand...

ever heard of punctuation?
 
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bsedwebt70-5.0

New Member
Jul 1, 2004
320
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0
Charlottesville, VA
Jul 27, 2007
#5
  • Jul 27, 2007
  • #5
That gives me an idea - I have both 19 & 24 # sample tubes on two 76mm C&L MAFs and 2 Mustangs - one with 19# injectors and one with 24#. I could try switching them around with each other to see if I get better fuel mileage by tricking the computer into going lean. Anybody have any experience with this? I have gotten a best of 29mpg at a steady 70mph on a extended highway trip with no stop and go on my 24# injectors with matching 76mm C&L 24# tube with lots of other mods.
 

vristang

15 Year Member
Mar 31, 2005
4,933
101
124
Seattle
Jul 28, 2007
#6
  • Jul 28, 2007
  • #6
bsedwebt70-5.0 said:
That gives me an idea - I have both 19 & 24 # sample tubes on two 76mm C&L MAFs and 2 Mustangs - one with 19# injectors and one with 24#. I could try switching them around with each other to see if I get better fuel mileage by tricking the computer into going lean. Anybody have any experience with this? I have gotten a best of 29mpg at a steady 70mph on a extended highway trip with no stop and go on my 24# injectors with matching 76mm C&L 24# tube with lots of other mods.
Click to expand...
While it does sound promising at first, this isn't a good plan...

The ecu has a correction ability for the fuel metering. If the O2 sensor is seeing a lean condition, then the ecu will simply increase the pulsewidth until the mixture comes back to stoich.

Best case scenario, swapping sample tubes as you have described will have ZERO net effect.
Worst case scenario, is that the lean condition is out of range of the ecu's ability to correct, and you start having detonation issues. If you have cats, they could be damaged as well.


It would be best to use the correct sample tube, and look for MPG gains elsewhere.



jason
 
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