S2KP

Anyone know what is needed to read the duty cycle on injectors? I know the Apex AVCR has an option for it. What are the others?

austrian type-R

standalone ECUs mostly every brand. Maybe an electronical guy can custom build you a unit with parts from en electronic store?

John_at_J&S

Duty cycle is the ratio of time on to time off, expressed in percent. 0% means the injector never opens, while 100% means that it is on full blast.

An old fashioned dwell meter could be used to measure injector duty cycle. Connect one lead of the meter to 12v, the other lead to the ECU side of the injector.

Dwell meters show the number of degrees that the points are closed, which is the same thing as showing when the ignition coil is "on". The calibrations are not crank degrees, but cam degrees, since the points were opened and closed by the cam.

A four cylinder engine fires once every 180°. In theory, you could let the points stay closed for nearly 180° crank degrees, before making the next spark. A dwell meter would only show 90°, since it's calibrated to show cam degrees.

To use an old dwell meter to display injector duty cycle, connect one lead of the meter to 12v, and the other lead to the ECU side of the injector.

Set the meter to "4 Cyl". Note that 90° is the max reading. This is 100% duty cycle. 0° would be 0%, and 45° would be 50%.

To convert from degrees to duty cycle, multiply the reading by 1.11.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by John at J&S &raquo;</TD></TR><TR><TD CLASS="quote">Duty cycle is the ratio of time on to time off</TD></TR></TABLE>

Duty cycle is the ratio of on time to TOTAL time. But John is right on with the dwell meter idea.

Charlie Moua

iTrader: (3)

OT: so how do you pronouce DUTY?

DA-MAX

this is what I plan to get(the one at the bottom of the page), pretty handy for $65

http://www.impconcepts.com/fue...e.htm

John_at_J&S

Forgot to engage brain. Thinking is hard work.

raene

I'm wondering why you couldn't make your own fuel injector duty cycle monitoring device...?

I see one 14-pin chip, one 18-pin chip, a blank board, a bunch of resistors, several capacitors, a ribbon cable and a bunch of LEDs. AFAIK chips are worth like $1 apiece, resistors are like $5 for a handful, capacitors are about the same, and LEDs are the most expensive - probably $20 for the LEDs, and about $5 for the ribbon cable. That's not even buying bulk!

I wish I knew more electronics... augh... anyone have links to info where I could possibly learn how to build my own?

DA-MAX

dude I'm with you 100%, but electronics tinkering to that level isn't my game(funny thing is I bet its not really that hard ) I'll just have to cough up the cash I guess

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">I'm wondering why you couldn't make your own fuel injector duty cycle monitoring device...?

I see one 14-pin chip, one 18-pin chip, a blank board, a bunch of resistors, several capacitors, a ribbon cable and a bunch of LEDs. AFAIK chips are worth like $1 apiece, resistors are like $5 for a handful, capacitors are about the same, and LEDs are the most expensive - probably $20 for the LEDs, and about $5 for the ribbon cable. That's not even buying bulk!

I wish I knew more electronics... augh... anyone have links to info where I could possibly learn how to build my own?</TD></TR></TABLE>

raene

I'm really waiting for some electronic guru to post... I mean, everyone is talking about injector duty cycle all the time, when all I see is injector pulsewidth in ms or what have you in Hondata or Uberdata or whatever. Are they just looking at the dynographs and figuring out when the injectors go 100% by the bog in power or is there something simple we're missing out on?