Frequency Counter as FE Meter? - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 11-25-2007, 03:41 PM   #1
Registered Member
 
Join Date: Aug 2007
Posts: 107
Country: United States
Frequency Counter as FE Meter?

I'm thinking about trying something like this for a FE meter

http://cgi.ebay.com/9999Hz-LED-Digit...QQcmdZViewItem

It seems like it would be handy for counting injector pulses to see what gear would be best for driving to see if it's better at 1500 rpm in one gear or 2000 rpm in another etc
__________________

FritzR is offline   Reply With Quote
Old 11-25-2007, 06:49 PM   #2
Senior Member
 
CoyoteX's Avatar
 
Join Date: Dec 2012
Posts: 230
Country: United States
Location: Southern WV
I think the main thing you need to measure is pulse width. I am not sure if the injector frequency changes at all but I know the % on to the % off ratio is where you can tell how long the injectors are open and how much fuel they are dumping into the engine. I am not sure if anyone makes a meter to measure it though.

If you can find one let us know cause I would like to have something to measure the injectors with
__________________

CoyoteX is offline   Reply With Quote
Old 11-25-2007, 10:37 PM   #3
Supporting Member
 
cfg83's Avatar
 
Join Date: Sep 2006
Posts: 1,779
Country: United States
FritzR -

Sorry, can't say anything intelligent. This just looks plain cool! If not for an FE meter, why not for another type of gauge? What else could be called a "frequency sensor"? An A/F ratio meter?

CarloSW2
__________________
Old School SW2 EPA ... New School Civic EPA :

What's your EPA MPG? http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
cfg83 is offline   Reply With Quote
Old 11-26-2007, 09:17 AM   #4
Registered Member
 
Rick Rae's Avatar
 
Join Date: Jun 2007
Posts: 240
Country: United States
Quote:
Originally Posted by Coyote X View Post
I am not sure if the injector frequency changes at all...
Erm... injector firing frequency would be directly related to RPM, wouldn't it? As in, RPM/2 on any given injector for a four-stroke?

Rick
__________________
Rick Rae is offline   Reply With Quote
Old 11-26-2007, 10:41 AM   #5
Site Team
 
Join Date: Dec 2006
Posts: 656
Country: United States
Quote:
Originally Posted by Rick Rae View Post
Erm... injector firing frequency would be directly related to RPM, wouldn't it? As in, RPM/2 on any given injector for a four-stroke?

Rick
I think some TBI systems don't correspond exactly to RPM. But even there, without measuring pulsewidth, there is no way to tell how much fuel is being used.
__________________
Think you are saving gas? Prove it by starting a Gas Log, then conduct a proper experiment.
bobc455 is offline   Reply With Quote
Old 11-26-2007, 11:16 AM   #6
Registered Member
 
Join Date: Aug 2007
Posts: 107
Country: United States
Oh well just a thought. I thought the injectors put out a certain amount of fuel for each pulse
FritzR is offline   Reply With Quote
Old 11-26-2007, 11:59 AM   #7
Registered Member
 
Rick Rae's Avatar
 
Join Date: Jun 2007
Posts: 240
Country: United States
Quote:
Originally Posted by bobc455 View Post
I think some TBI systems don't correspond exactly to RPM.
Ah... I didn't even think about throttle body injection. Thanks.

Quote:
But even there, without measuring pulsewidth, there is no way to tell how much fuel is being used.
Sure. I was just commenting on whether the injection rate changed or not.

Rick
__________________
Rick Rae is offline   Reply With Quote
Old 11-26-2007, 09:19 PM   #8
Registered Member
 
GasSavers_bobski's Avatar
 
Join Date: May 2007
Posts: 463
Country: United States
Quote:
Originally Posted by Coyote X View Post
I think the main thing you need to measure is pulse width. I am not sure if the injector frequency changes at all but I know the % on to the % off ratio is where you can tell how long the injectors are open and how much fuel they are dumping into the engine.
Exactly.
As has been said, measuring the frequency would tell you how often the injector fires, but now how long it stayed open and therefor how much fuel it injected.
What you're looking for is something to measure duty cycle at a relatively quick pace. Many automotive multimeters have this function. Just check the package to make sure it will register values from 1-2% on up to 80-90%.
GasSavers_bobski is offline   Reply With Quote
Old 11-26-2007, 09:37 PM   #9
Registered Member
 
kamesama980's Avatar
 
Join Date: Nov 2007
Posts: 742
Country: United States
Location: Columbus, IN, USA
Send a message via AIM to kamesama980 Send a message via Yahoo to kamesama980
almost all engines base the injector opening time on rpm. you need pulsewidth AND frequency. frequency is rpm (usually not /2) usualyl based off the crank angle sensor (cam position sensor (located in the distributor in non-coilpack ignition) in older cars) pulsewidth is based on rpm, airflow/temp, and load (throttle position)
__________________
-Russell
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"
kamesama980 is offline   Reply With Quote
Old 11-27-2007, 07:52 PM   #10
Registered Member
 
Snax's Avatar
 
Join Date: Mar 2007
Posts: 758
Country: United States
A simple low-tech way to measure relative consumption would be to build a circuit that drives a meter or a lamp off of a capacitively charged circuit that gets it's input off of one of the injectors. Obviously faster or longer pulses will convert to more throw or lighting of the meter.

It would be relatively easy to design using a buffer driver and an LED bar graph IC or other digital display. It would be more of a challenge to get real world numbers out of it, but calibrated to read a 1 at lowest load and 10 at the highest, one could certainly make some reasonable assumptions about efficiency.
__________________

__________________
LiberalImage.com

I think, therefore I doubt.
Snax is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Diesels are very efficent at idle? philmcneal Diesels 36 04-05-2007 07:25 PM
GasSavers.org Stickers Matt Timion Fuelly Web Support and Community News 7 10-12-2006 04:48 PM
FFI GasSavers_MPGmaker Introduce Yourself - New member Welcome 39 05-30-2006 04:31 PM
State of the Union address touches on "oil addiction." Matt Timion General Discussion (Off-Topic) 31 02-06-2006 04:38 PM
Where to get parts? What parts do we need? Matt Timion Electric and Solar powered 11 09-19-2005 09:37 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 10:59 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.