FlamedROC

Hey me and my dad can not come to an agreement on how a fuel injectors work...Heres the question we started out with...

What makes a 19lb injector different from a 24 lb injector? Also we then started describeing how an injector is set up. Also why is a 19lb injectors ohm resistance greater than the 24 lb injectors? the 19's had 16.5 ohms and the 24's had 14.5 ohms.

I would like to see diagrams/pics/tables...and I want to see how an injector is built inside and what holds it open/what causes it to be held open etc.

His theroy is---The (stock)19 lb injector has a larger outlet nozzel there allowing the injector to flow more because of the greater opening in the nozzel. With say 36lbs at the rail he believes that there is more pressure at the nozzel which limits the flow of fuel. No matter the fuel pressure u are still limited by the nozzel opening

My theroy is--- By increasing the lb injector to 24 lbs you are allowin more fuel to flow by. The way the injector is built is to run more fuel through its self during a Pulse Width. And by bumpin up fuel pressure u are allowin even more fuel to flow through the injector. The accel 24lb injector had a smaller nozzel outlet than the stock 19 lb injector. Which I think is for better atomization of the air/fuel comin in

Also what does the 19/22/24/26 lb ratings mean? Lbs per minute? pressure at the rail? what?

Please someone give me as much info as u can!!!

shaggy56

Heres the genius of the internet by using things like google and other search engines. They make it easy to learn things like this. The oxygen sensor to me is the most impressive. Makes me wonder how did they figure that out.

http://auto.howstuffworks.com/fuel-injection3.htm

FlamedROC

I like the diagram....but that really didnt answer any of my questions that I had....so keep em comin please!!

shaggy56

"I would like to see diagrams/pics/tables...and I want to see how an injector is built inside and what holds it open/what causes it to be held open etc."

If that link didnt answer your question then good luck getting an answer.

Heres a second opinion. Wasnt hard to find. I dont know what your looking for. Made sense to me.



http://www.twminduction.com/EFI/EFIInjectors.html

FlamedROC

that was the best yet!! thanks man...well how do they come up with lb ratings? For example why is 24 better than a 19lb? is it how the injector is built or is it openin wider or what is goin on to make it flow better..I'm confused with the terminology and the mathimatics it takes to figure out flow rates...

shaggy56

" Static flow rates quoted are the result of testing at 43.5 PSI (3 Bar). Static flow is measured with the injector held open. Static flow rate tolerance is ± 3%."

Later in the link it explains

" Remembering that injector capacity quoted in the table, is static flow, we must now increase this number by multiplying it by 1.25 to allow the injector to operate at no more than 80% of its static flow."

I would assume that a larger injector would be able to open more allowing more fuel to be released. Injectors are calculated at pounds of fuel per hour at wide open throttle I would imagine

This part explains how fuel is metered to the engine

"The quantity of fuel delivered is controlled by the length of time the injector is open. This is referred to as pulse width. "