View Full Version : Possible Fuel System FAQ


NJHK
01-30-2007, 08:59 PM
Ok, I wasn't sure if I should make a post but I decided to anyways.

Me and Scott @ Cobalt Performance Parts have been talking alot about this and I constantly see confussion on fuel injectors and fuel systems in general.

I wanted to compile an FAQ and I guess...try...to make it ECOTEC related while still serving a general purpose.

So noobies or even experienced people, are there any questions about fuel systems at all that you're just confussed on and want a better explination on? Please ask the questions here.

Also, this is QUESTIONS ONLY please, no answers here. All questions will be approved and listed in the FAQ when I write it up. It will be the same style and I will do it the same way I did the Turbo FAQ (I'll try to get as many pictures as possible).

Thanks for your time.

TCarter
01-30-2007, 09:22 PM
Why doesnt Mr. Adam post what fuel injectors are, and what a fuel system is for our cars. :)

rally
01-30-2007, 09:28 PM
Adam When should we upgrade our fuel injectors?

(I see a lot of these questions from day to day so figured I'd ask so hopefully people see this before they ask)

NJHK
01-30-2007, 09:30 PM
Yeah that's the # 1 question I see....I'll sure be addressing that.

rick1217
01-30-2007, 09:56 PM
Thats great Adam.....heres a few to start you off...

Whats size of fuel injectors come stock on all ecotec motors?
What are the limits of the stock fuel systems? We can use bigger injectors but how much will the rest of the fuel system support?
Do we need to upgrade the fuel system to run nitrous?(wet and dry kits)
What is a fuel pressure regulator? How does it work?
What happens(or can happen) if you max a fuel injector out?
What happens when a fuel injector goes "static"?
What is the differance between Low Impedance and High Impedance Injectors?
If I have Low Impedance Injectors, can I run High Impedance Injectors??

Thats just a few I can think of off the top of my head, Good Luck:twothumbs

NJHK
01-30-2007, 09:58 PM
FINALLY!

Thank you. All good questions.

HunterKiller89
01-31-2007, 01:22 AM
aight...i asked this a while back and got an answer...but i suppose it can join the list
whats the difference (pros/cons) between direct fuel inject and multi port fuel inject, along with other forms of fuel injection?
which ecotecs have which type of injection system?

06ChargedSS
01-31-2007, 10:02 AM
How about the different methods of supplying fuel to the injectors also? Returnless versus return systems. And if they can be interchangeable, or best used etc, etc...

bc3tech
01-31-2007, 11:10 AM
Adam When should we upgrade our fuel injectors?...on a 2.2... when u go F/I. on a 2.0, as stage kits require or as you like. and only do it if you have tuning.
Thats great Adam.....heres a few to start you off...

Whats size of fuel injectors come stock on all ecotec motors?
What are the limits of the stock fuel systems? We can use bigger injectors but how much will the rest of the fuel system support?
Do we need to upgrade the fuel system to run nitrous?(wet and dry kits)
What is a fuel pressure regulator? How does it work?
What happens(or can happen) if you max a fuel injector out?
What happens when a fuel injector goes "static"?
What is the differance between Low Impedance and High Impedance Injectors?
If I have Low Impedance Injectors, can I run High Impedance Injectors??

Thats just a few I can think of off the top of my head, Good Luck:twothumbs
1) 2.2's have 24# (or thereabouts) while the 2.0's have 32 (or 34)#rs
3) dry kits are a no-no. wet kits, no you don't have to change anything about the fuel system with size-appropriate wet kits.
4) FPR is used to increase fuel pressure in line with the amount of boost an engine sees. ideally you want 1psi fuel pressure increase for 1psi boost
5) you go lean, as the engine wants (needs to stay at right AFR) more fuel, but injector can't supply it. going lean causes detonation (knock) which causes *boom*
6) it stays open perpetually. depending on where it locks (closed, full open, in between) you can go lean (boom), be rich (shitty performance), or not notice that much

Edubs
01-31-2007, 11:17 AM
Also consider expanding upon the traditional injector upgrades for LSJ guys. Most only think of the 34lbs, 42lbs and 60lbs injectors. Try and address the availability of injectors like the 50lbs ones Cobaltperformanceparts offers. The limits of those 50lbs injectors and the tuning implications with anything outside of stock/GMS2-3...

sushidog
01-31-2007, 11:34 AM
How about these.

What is injector scaling, and what's the best way to adjust for bigger injectors?

What are a matched set of injectors and what difference do they make?

What are the diferences between injector brands as far as function, ie. atomization, spray patterns, how closely they match, etc.?

Whats the difference between biggyback and stand alone fuel management? What are the problems associated with each?

How about posting up some injector calculators, like those on RC's site.

Thanks, Adam!!!

Witt
01-31-2007, 03:34 PM
A few that should clear up common questions to include in your FAQ, sorry if they were posted earlier.

What fuel pressure do Delta bodies run at?
What fuel pressure are injectors rated at?
Do we have a return or returnless fuel system?
Does an adjustable fuel pressure regulator work on these cars without significant modification? What are those modifications needed?
What effect does alky/meth injection have on octane ratings?
What effect does octane ratings have on timing advance?
Does the fuel rail contain a test port to install wet nitrous systems?

I'll think of more as time goes on. Lemme know if you need any help answering anything as well.

NightriderCobaltSS
01-31-2007, 03:37 PM
Also What effect the MAF and MAP Sensors have on flow Flow Rate? and how if one of them is malfuntioning you might see problems with the fuel system.

NJHK
01-31-2007, 05:31 PM
on a 2.2... when u go F/I. on a 2.0, as stage kits require or as you like. and only do it if you have tuning.

1) 2.2's have 24# (or thereabouts) while the 2.0's have 32 (or 34)#rs
3) dry kits are a no-no. wet kits, no you don't have to change anything about the fuel system with size-appropriate wet kits.
4) FPR is used to increase fuel pressure in line with the amount of boost an engine sees. ideally you want 1psi fuel pressure increase for 1psi boost
5) you go lean, as the engine wants (needs to stay at right AFR) more fuel, but injector can't supply it. going lean causes detonation (knock) which causes *boom*
6) it stays open perpetually. depending on where it locks (closed, full open, in between) you can go lean (boom), be rich (shitty performance), or not notice that much

Seriously...PLEASE READ THE ORIGINAL POST

I was thinking about this...

I didn't want to make this too application specific. I think before we can get specifics, people need to understand the basics of how things work. I want this to be something spread accross the board kind of thing, not necessary a "Cobalt Fuel system FAQ".

I mostly made this to help out people who are clueless or just slightly confussed as to how a fuel system works. I'm almost done with it...on page 6 on my word document and having some people revise it to make sure I didn't screw up on it from me writing it at 4 am (I was pretty tired but motivated lol)