Injector Pulse Width?

rammertide07 · #1 Tue, April 17th, 2012, 11:46 AM

Is there any relation in injector pulse width and fuel milage? Seems like the shorter the pulse width, the less fuel going into the cylinder...if I'm thinking injector pulse width is pretty much as its called.

***907DAVE*** · #2 Tue, April 17th, 2012, 09:03 PM

Correct, pulse width is a measurement of how long the injector is commanded on. So, shorten the PW and less fuel gets injected.

However, on a HEUI injector, ICP plays a major roll in fuel delivery also. More ICP = more fuel...faster. If PW was to remain constant and ICP was to increase, more fuel will be injected.

Make sense?

rammertide07 · #3 Wed, April 18th, 2012, 07:19 AM

Quote:

Originally Posted by 907DAVE

Correct, pulse width is a measurement of how long the injector is commanded on. So, shorten the PW and less fuel gets injected.

However, on a HEUI injector, ICP plays a major roll in fuel delivery also. More ICP = more fuel...faster. If PW was to remain constant and ICP was to increase, more fuel will be injected.

Make sense?

Kinda, doesn't that just mean the pulses of fuel are the same....just under more pressure with more oil? Or is it squeezing in more fuel with more pressure?

ticopowell · #4 Wed, April 18th, 2012, 08:18 PM

I think both come into play, with ICP, more pressure equals more fuel, but the pulse width is still variable based on what the computer says.

***907DAVE*** · #5 Wed, April 18th, 2012, 10:18 PM

Quote:

Originally Posted by rammertide07

Kinda, doesn't that just mean the pulses of fuel are the same....just under more pressure with more oil? Or is it squeezing in more fuel with more pressure?

Sorta, more pressure driving the fuel plunger means more fuel is going to be injected in the same amount of TIME. Remember, pulse width is a measurement of the injector "on" time - regardless of how much fuel is actually being delivered.

Quote:

Originally Posted by ticopowell

I think both come into play, with ICP, more pressure equals more fuel, but the pulse width is still variable based on what the computer says.

Yup, but so is ICP.

rammertide07 · #6 Thu, April 19th, 2012, 11:17 AM

Quote:

Originally Posted by 907DAVE

Sorta, more pressure driving the fuel plunger means more fuel is going to be injected in the same amount of TIME. Remember, pulse width is a measurement of the injector "on" time - regardless of how much fuel is actually being delivered.

So fuel plunger travle depends on oil pressure? I always thought it was the same travle distance each time.