stock injector deadtime for 4age 20v silvertop/blacktop injector

ditn
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Joined: Sat Jan 12, 2013 7:34 am

stock injector deadtime for 4age 20v silvertop/blacktop injector

Postby ditn » Fri Feb 19, 2016 11:04 am

Does anyone know the stock injector deadtime for 4age 20v silvertop/blacktop injectors with stock fuel pressure regulator.
@14V
@12V
@10V
...

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s24a
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Joined: Mon Jan 14, 2013 9:40 pm

Re: stock injector deadtime for 4age 20v silvertop/blacktop injector

Postby s24a » Fri Feb 19, 2016 2:50 pm

If you have access to an oscilloscope, a knock sensor or accelerometer and a variable DC power supply you can measure this yourself.
You should really also have fuel pressure against the closed injector to get an accurate reading, as this will influence the opening time.
So also have the injector in a bucket to catch the fluid coming out. I recommend using a light oil like kerosene just for safety. It will be close enough that difference to gasoline is negligible.

Hook one channel of the scope to the power supply. The other channel will be to the knock sensor or accelerometer which is attached to the injector body.
You can use the top "cal" pin dimple of the injector for this or the bottom of the valve body. You may have to make a metal adapter ideally to attach it securely if the vibration transfer from the fuel rail is insufficient.

Have the scope trigger on turning on the power supply (that channel, rising edge), and do a one-shot capture. Set timebase to milliseconds as this is range you need.
Repeat this for each voltage you want several times to average. Dial it down to about 6V or so, since the ignition will quit around that voltage.

BTW....actual "deadtime" as used by injector engineers is = opening time - closing time, but I believe you just want to get the opening time battery correction transfer function for the injector.

Have fun! This can be very interesting to do!

Hank Dozier
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson