2G Fuel system upgrade

[v-mac]

im running a evo 3 Big 16g and i just bought some 560cc injectors and a evo 9 fuel pump, after putting these in i will be able to prevent my fuel cut out like im experiecing right now, but will i need to do anything to get the car to run right after the instal as far as a tune, and if so what will i need to do, or will the car configure itself and run like usual?

 

[kenamond]

You need to do some homework. Fuel cut doesn't mean your car is running out of fuel, it means that you're flowing more air than the ECU will permit (which tells me you have your boost controller set too high and are risking your motor's life). And if you change injectors, the ECU thinks you still have the stockers and will inject (in your case) too much fuel. SAFC, ECMlink and AEM-EMS are all options for fixing this. If the Evo fuel pump flows a lot more fuel than your stock pump (don't know much about that pump), then you may overrun your stock fuel pressure regulator, which means you run rich, because the stock FPR can't let enough fuel return from the rail (it's too small). This would mean you need an adjustable FPR (AFPR) such as a fuelab or aeromotive unit.

 

[redmitsu95]

+1 SAFC or possibly a GM Maf w/ Translator GenII or pro

 

[v-mac]

im running out at 10PSI you can tell its fuel cut as soon as i let off the gas 1psi it starts back smooth, and its set for 10psi thats the lowest i could possibly get it im not running high boost,

 

[dawid4444]

you will need tune your car if u want to put biger injectors
do u have a/f gauge ?? and apexi SAFC ?? to tune it ??
or DSMlink ??
cause if u gona put just biger injector your ecu will think that its still the stock one 450cc and u will be drive too rich
and u have to tune it with dsmlink or
apexi SAFC its the best to tune it

 

[kenamond]

Another common cause of fuel cut is a boost leak. If the intake is leaking between the turbo compressor and the motor (boost leak), you end up pulling more air through the mass sensor than the engine is getting, and the ECU hits its airflow limit sooner and cuts fuel (fuel cut). You'd also be running rich, which will rob power. Boost leak testing is something you should be doing anyway (every other oil change is what I do), and your car should be in good working order before you try getting more power out of it.

 

[v-mac]

the engine was completely rebuilt two months ago, and wouldnt i be able to tell if it was leaking? if it were somethign that bad id think i would be able to hear a hint of a whistle or something? also will an SAFC 2 work for this issue? i appreciate the help fellas, oh yea sorry i have a aem uego for AF monitoring as well

 

[v-mac]

alright what your talking about running rich, say if i floor the pedal and at high boost im readin 10 on the AF does that mean im leaking boost? or could it be something else id like to learn a little bit so i can fix whatever you think issue i could possibly have that im not aware of

 

[lazyazzdaddy]

alright what your talking about running rich, say if i floor the pedal and at high boost im readin 10 on the AF does that mean im leaking boost? or could it be something else id like to learn a little bit so i can fix whatever you think issue i could possibly have that im not aware of

when your a/f is at 10 it is way to rich. "i believe that's where your a/f gauge maxes out. so it's most likely even richer than that" when you floor it people generally aim for 11.1 and when your idling or just driving around normally you want it to read 14.7

you really need to get some sort of fuel control or switch back to stock injectors.

you should also check out th faq's : Frequently Answered DSM Questions - DSM Forums

 

[v-mac]

i am in stock injectors i have not got the 560ccs or put in the evo nine fuel pump im running stock beside the evo3 big 16g what would running this rich mean?

also my idle and cruise is fine on the AF between 14.5 and 15.2 but idles a 14.8 so that is good

 

[lazyazzdaddy]

i am in stock injectors i have not got the 560ccs or put in the evo nine fuel pump im running stock beside the evo3 big 16g what would running this rich mean?

also my idle and cruise is fine on the AF between 14.5 and 15.2 but idles a 14.8 so that is good

sorry i did read that but for some reason was thinking injectors. either way though your over running you fuel pressure regulator with that fuel pump. you really should consider putting the old one back in until you can get a adjustable fuel pressure regulator and gauge.

 

[kenamond]

when your a/f is at 10 it is way to rich. "i believe that's where your a/f gauge maxes out. so it's most likely even richer than that" when you floor it people generally aim for 11.1 and when your idling or just driving around normally you want it to read 14.7

Not true. The stock fuel maps put the AFR around 10. If you're tuning, you shoot for 11-12. If you run 14.7 (stoich) under boost, you'll wreck your motor.

the engine was completely rebuilt two months ago, and wouldnt i be able to tell if it was leaking? if it were somethign that bad id think i would be able to hear a hint of a whistle or something? also will an SAFC 2 work for this issue? i appreciate the help fellas, oh yea sorry i have a aem uego for AF monitoring as well

You won't hear a hiss. During a boost leak test, you apply pressure to the compressor inlet (maybe 20psi) and see how slowly it leaks down. There are a lot of places for air to leak out. Common places are your TB gaskets, BISS o-ring, BOV gasket (if aftermarket), BOV itself, injector insulators, IC couplers, IC (gets corrosion holes), and hoses (if stock...they're rubber and can crack), PCV valve, and a few vaccuum lines. There are other places. A rebuilt motor doesn't mean they changed all of the gaskets and did a boost leak test, but maybe they did. Anyway, you need to know how to boost leak test if you own a DSM with stock mass airflow sensor (MAS). When folks talk about a GM MAF or blow-thu setup, you basically are moving the MAS to after the turbo, and that makes the setup less sensitive to boost leaks.

alright what your talking about running rich, say if i floor the pedal and at high boost im readin 10 on the AF does that mean im leaking boost? or could it be something else id like to learn a little bit so i can fix whatever you think issue i could possibly have that im not aware of

An AFR of 10 under load (WOT) is normal. I don't remember the whole 2g fuel map, but I recall that it's in that ballpark...it's certainly not bad. At idle and cruise, the AFR should be around stoichiometric (14.7) which is what it looks like you're seeing.

Anyway, do a boost leak test. Search on it. Most of us who are wrenching on our cars do them.

But before you can upgrade your injectors, you need SAFC/SAFC2 or other fuel controllers. You should be okay with 560cc/min injectors on an SAFC setup. Rule of thumb is that it'll work up to around 660cc/min injectors. The SAFC intercepts the signal from the MAS and lies to the ECU about airflow...it tells it there's less air. That makes the ECU pulse the larger injectors less. Since they're bigger injectors, a shorter pulse is required to get the same fuel as the smaller, stock injectors. You get to fiddle with knobs until you get the ECU to pulse the larger injectors "just right". Since the ECU is being told that less air is entering the motor, it takes more *actual* airflow to hit fuel cut, so you can push your turbo harder without hitting fuel cut. But that also requires a larger fuel pump (the stock pump is maxing out at 15ish psi boost). So if you get injectors, a larger pump, and something like SAFC, you should be able to tune for boost higher than 15psi.

Long story short, if you get an evo3b16g turbo, 560 injectors, a bigger pump, an SAFC, and a good tune on that SAFC, you should be able to run higher than 15psi boost (maybe 20psi) and still get enough fuel to keep your AFR around 11. But you need to do some homework to know how to do this safely, or you're rolling the dice on your motor.

 

[counti41]

its really hard to tell what ## problem is really...an evo3 at 10 psi ## already flowing way more than the stock t25. getting urself an afc and have someone that knows what there doing tune it for u...well of course after the pump and injectors...it is possable to still run the stock fpr with larger injectors and higher flowing fuel pump...afpr would make controling ## af a lot easier. i dont even hava an afpr yet but the car runs steady 11.6 af all day

 

[kenamond]

its really hard to tell what ## problem is really...an evo3 at 10 psi ## already flowing way more than the stock t25. getting urself an afc and have someone that knows what there doing tune it for u...well of course after the pump and injectors...it is possable to still run the stock fpr with larger injectors and higher flowing fuel pump...afpr would make controling ## af a lot easier. i dont even hava an afpr yet but the car runs steady 11.6 af all day

It depends on how much an evo9 pump flows. Wally255 pumps will overrun your stock fpr bigtime at low airflow, and this means you'll run rich in the low revs and have horrible fuel economy.

I'd have to look at the compressor maps for the T25 vs. the e3b16g, but I don't think the evo turbo flows much more (maybe even less) at 10psi, while the T25 is on its efficiency island at 10psi. Anyway, I'm skeptical that an evo3b16g outflows a T25 by a lot at 10psi boost.

 

[counti41]

YouTube - street racing ok this was 720 cc injectors and a wally 255hp, stock 99 ecu and afc tune at 20 psi

 

[v-mac]

the evo 9 flows about 200lph, right now i am running stock everything, so if i get an SAFC i can run the 560cc injectors and evo 9 pump and be fine with a good tune is what your saying? i will look into the boost leak testing and try to figure all that out

 

[lazyazzdaddy]

Not true. The stock fuel maps put the AFR around 10. If you're tuning, you shoot for 11-12. If you run 14.7 (stoich) under boost, you'll wreck your motor.

I think you must have misread my post. or maybe the way i wrote it was misleading. i was refering to the fact that the aem uego does not read below 10. so if he was reading 10 chances are that he is actually richer than that.
other than that we agree on the rest.
Originally Posted by lazyazzdaddy
when your a/f is at 10 it is way to rich. "i believe that's where your a/f gauge maxes out. so it's most likely even richer than that" when you floor it people generally aim for 11.1 and when your idling or just driving around normally you want it to read 14.7

 

[kenamond]

I think you must have misread my post. or maybe the way i wrote it was misleading. i was refering to the fact that the aem uego does not read below 10. so if he was reading 10 chances are that he is actually richer than that.
other than that we agree on the rest.

I know that is a wideband O2 sensor, and I've heard it's not very good, but if it maxes out at an AFR of 10, that's *really* bad. The stock fuel map has spots with 9.7 or so on it, if I recall correctly. But if what you say is true, he has no idea how rich he's running. But the fact that he hits fuel cut at 10psi boost tells me he has a bad boost leak or a messed-up MAS.