FUEL INJECTORS ???

[flipz_ny79]

If Iam right our fuel injectors for the 7g's are 285c , does anyone know if the eclipse's injectors are bigger. If they are, would we be able to use them and take the fuel rail if needed ? :?:

[flipz_ny79]

Thankz! appreciate it.

[schick]

What are the flow rate for the Eclipse injectors?

[Nick VR4]

i think
its 1989-up Eclipse Turbo Peak and hold 450cc

[cantbeatmy97]

if u get bigger fuel injectors u might as well get a perfomance fuel rail at the same time to actually feel the difference

[schick]

Your car's computer will keep the fuel trim in check, by reading the O2 sensor, it will know if it's running to rich or too lean and control the flow of the injectors.
You really won't benefit from higher flowing injectors (or other means of higher fuel flow) unless you have a high amount of air coming in. The only way to get that high of a flow is usually through turbo or super charging. (but sometimes NA could use them)

I talked to a guy at a local tuner shop. He said if I had a CAI, header, exhaust, and port/polish it might be beneficial to upgrade fuel delivery, because the stock fuel system in a Galant is a little lacking. But he also said I should get something like an Apexi S-AFC for controling it.

[Jesse]

a/t = 390
m/t = 450 in 2g

all a/t and m/t = 450 in 1g


For nitrous, turbo, and other applications where you're running a little lean, then it's a good idea to beefen up the fuel delivery system.

With some research I did, it appears we have the same fuel pump as a 2g turbo fwd (gst).

So we're all good there.

Just a re-wire of the pump and you should be excellent.

[schick]

Jesse, for those that don't understand, what does rewiring the fuel pump do?
And how do we do it? (which wires?)

[g96nt]

umm
jesse you're backwards

all 2g's were 450CC

1g AT's were 390Cc
1g MT's were 450CC

and schick?

your computer can *NOT* compensate For bigger injectors
well.. it could... but not enough...
for 450's

[schick]

Craig, please clarify "not compensate"
Are you saying that you won't benefit from larger injectors with the factory ECU, OR that You will get a higher rate of flow with the factory ECU and larger injectors and it will always run rich?

Let's dive further into this: PLEASE REMEMBER this is only my interpretation of what happens. I could be wrong. If I am, and you have empirical or in-depth knowledge of how this works, by all means SHARE IT!
For a primer on fuel injection CLICK HERE to go to the Howstuffworks.com site.

First, What does a fuel injector do? Basically, it injects fuel into the air stream flowing into the combustion chamber through the intake valve.

Next, let's describe how the ECU controls the amount of fuel that gets injected. The ECU (engine computer) regulates how much fuel gets injected by shortening or lengthening the amount of time the injector stays open (pulse width). It reads the A/F mixture of the exhaust gas (O2 sensor), MAS sensor, TPS, even the engine speed.
Less air, running rich, or idling? - ramp down the flow of fuel.
More air, running lean, or at WOT? --> need more fuel.

Third, how does a larger injector affect all this?
Think of this as an example of what higher flow injectors will do;
You have two injectors,
"A" flows at 200cc's per second max, "B" flows at 400cc's per second max.
Your ECU says "injector, let half a second worth of fuel enter the air stream". That's 100cc for "A" and 200cc for "B"
Remember, the amount of air is the same! "B" will be richer than "A".
Remember, with an amount of air you will also need a certain amount of fuel. (somewhere around 14:1 air:fuel ratio is about right for internal combustion engines). With higher flow injectors, at the same pulse width as a factory injector, you will get a rich mixture. Your ECU will sense this (O2 sensor) and shorten the pulse width so that the amount of fuel will be the same. (math time - one second pulse of 200cc/sec is 200cc, half second pulse of 400cc/sec is... 200cc approximately)

OK, what if we force more air into the engine? gee..... we will need more fuel? BINGO!
If you have twice the amount of air, you will need twice the amount of fuel. The factory injector will be fine, until it reaches its max flow
If the factory injector maxes out at 200cc/sec and you need 300cc/sec for the amount of air coming in, you will be running lean.
What does this mean when using the factory ECU?
Remember that if you double the max flow rate of an injector, you half the pulse width to get the same amount as a factory injector. As the factory injector maxes out at 200cc, the 400cc injector will only be running at half its max along with half its pulse rate. At full pulse width it will be flowing 400cc's. It's all about overhead.
However, remember that the ECU will only utilize the higher flow of the larger injectors if you supply more air.

*Please note - the math and flow rates above are only meant to be represented as examples. They are NOT exact measurement!.[/url]

[Kain]

But, remember. Your ECU was designed and programed for YOUR car. That is one thing that is never universal. Even cars with identical engines (just as an example off the top of my head, the Celica and Matrix) can/do have diffrent ECUs. The ECU is calibrated for stock equipment and standard variables within accepted limits (this is to compensate for variances in production, as no two cars are exactly identical) If you change the fuel injectors drasticaly from the norm (stock) the ECU will not be able to fully compensate as the values being given to it by the O2 sensor will be outside the normal variation. The ECU will read this as a problem, and will compensate as best as it can. This will still result in poor running. However, schick is right. If you have more air, it will be irrelevant as this will compensate for the extra fuel. But it takes a lot of extra air. So, for most people with minor mods, the stockers are fine. If you're getting a great deal of extra air (I.E. serious N/A mods, turbo, supercharger) you'll want/need bigger fuel injectors. And remember, lean=BAD in cars. All stock fuel injectors have a good chunk of leway in them to protect against running over lean, or over rich. As we all know fuel injectors get dirty, when they do they can't operate at 100% efficiency, and would kill the engine very quickly if they were not capable of delivering more fuel than they need. Umm...I hope that makes sense. Bottom line: Bigger fuel injectors with stock ECU will need capacitors to run properly.