Fuel Filter Remove=Trapped Air?

[waskly]

Consider that at 6000 eng. rpm, each piston must make it's journey up and down within it's cylinder 100 times every second! Given 4-cycle operation, each injector must "fire" 50 times per second: that's ONCE EVERY 20 milliseconds (0.02 sec.). Picture in your mind exactly WHEN the injector must fire: sometime either just BEFORE the intake valve opens, or immediately AFTER it starts to open, (depending on the particular engine) and the "squirt" of fuel must CEASE well before the piston reaches bottom of stroke, so the "time window" during which the injector can be open is much less than even 20 ms, and probably less than 10 ms.

These rate of operation facts are indisputable, if the crank is to turn at 6000 rpm. Long injector pulse times COULD be used at low engine speeds, but to achieve that, and still allow high-speed operation would require much reduced fuel pressure at those low speeds. (The discharge cross-sectional area of the injector's orifice is fixed by manufacture). I don't THINK they are varying fuel pressure to achieve this, but then my "THINKS" have often been wrong before!! imp

well the pcm controls how long an injector is open for, this is done in ms, i never actually bothered to look at injector ms under wot. but most cars like even explorers have a variable fuel pump. and a return less system.

the question at hand is, its not direct injected, its valve injected, when the valve is open fuel flows in. like even carbs, they just dump fuel its based on the flow of the intake manifold too distribute the fuel.

but as higher demand of fuel is met, pressure goes up, i just cant off the top of my head remember if time open is lower.

but dont get me wrong this is in milli seconds, even at 100ms which is .1 second, engine speed is still revolutions per minute.

so the injector even slower is still faster then what we measure the revolutions.

in theory (6000/60) = 100 == 1.4 seconds/2 valves .7 seconds the intake valve is open with a 100 ms squirt time, still plenty of room for other things.

^^^^ not sure this make sense atm, i'll look this over again hehe.

 

[1AJeremyD]

lol? sorry but no, that whole low pressure manual fuel pump system has been gone a long time. they are the same as gas.

both are idiot proof. diesel i think even more.

Ive worked on some 2006s and 2008s chevy 2500 and 3500 with the duramax diesel in them and they all had a push button pump on top of the fuel filter housing. It was a priming button. I've also done a lot of work with heavy equipment like Lulls and Caterpillars and all of them have to be primed in so sorts

 

[waskly]

Ive worked on some 2006s and 2008s chevy 2500 and 3500 with the duramax diesel in them and they all had a push button pump on top of the fuel filter housing. It was a priming button. I've also done a lot of work with heavy equipment like Lulls and Caterpillars and all of them have to be primed in so sorts

when i wrote that, i was still thinking of the most popular engines.

cumings / international.

chevy is garbage. i dont even consider or would even touch a duramax engine.

 

[1AJeremyD]

Cummings and John Deere have to be primed, as for international I have not had the pleasure of working on any of their trucks. Cummings have a primer pump on the side about 6 inches away from the filter.