Lean Problem

[ThePunisher95]

So my car Wide band goes very lean!! Under 2k rpms it will sometimes go all over the place from lean to rich which is normal but once I pass 2k rpms no matter what I do it goes lean enough to were the wideband cant read which is 17:1. I cant go full throttle and about 15 mph in forth gear and go wot and under 2k rpm its lower than 10:1 but once it goes about 2k or over it goes over 17:1 were the wideband cant read no more. Were do I start????

[fazm]

check fuel pressure, fuel filter, and check the fuel pressure regulator.

[DannyStyle22]

check fuel pressure, fuel filter, and check the fuel pressure regulator.


I agree.

[ThePunisher95]

How Do you check the the fuel pressure regulater???

[BurnTire]

How Do you check the the fuel pressure regulater???

Do you have a blower on the car?

[ThePunisher95]

Yes. A vortech

[BurnTire]

Fuel pressure gauge? Are you running an FMU or just large injectors?

[ThePunisher95]

Not yet. Gonna get the Tweecer to tune it. And I have a AEM Wideband. Im working on the fuel pressure gauge...

[99WhiteGT]

This happened to me. Check your fuel pump, thats what was wrong with mine.

[ThePunisher95]

49 lbs of fuel pressure and a new fuel filter. Still having the same problem

[fazm]

how bout the pressure regulator? pull the vacuum hose off of it after you shut it off and see if any gas is coming out.

mass air flow?

[ThePunisher95]

No gas is coming out... And I was thinking it could be the maf but I dont wanna spend 100 bucks and still have the same problem

[Sqrlnts]

What MAF are you using?

[ThePunisher95]

Stock

[fazm]

got anything to log data?

[jjmatheson]

The processor may not have the ability to log data in 91. I dont think this is your problem but check the elements on your maf, make sure its clean. Do you have an adjustable fuel pressure reg.?

[Sqrlnts]

Hope no one takes this the wrong way, but Punisher, if your looking to work more than one avenue at a time try SBFtech.com under Joel 5.0's Electronic Engine Management (http://sbftech.com/index.php?PHPSESSID=4322cb27414b1f601da977b11c7177 eb&board=20.0). There are some sharp cats on that forum.

Oh and, I asked what kinda MAF because I woulda let you try mine.

GL

[BurnTire]

49 all the time?

[ThePunisher95]

Hope no one takes this the wrong way, but Punisher, if your looking to work more than one avenue at a time try SBFtech.com under Joel 5.0's Electronic Engine Management (http://sbftech.com/index.php?PHPSESSID=4322cb27414b1f601da977b11c7177 eb&board=20.0). There are some sharp cats on that forum.

Oh and, I asked what kinda MAF because I woulda let you try mine.

GL

Were you live at?? I would like to use it just to try it out.

[Sqrlnts]

I am in Chandler Elliott and Dobson, my C&L MAF is calibrated for 24lbs injectors.....will probably give your 19's a hard time....

[Stern90LX]

If you're still running 19lbs injectors with a blower on there that's your problem. Way under sized for what you're doing. They just can't provide the amount of fuel per cycle that is needed in a boosted application. Even 24# injectors only support up to 300hp nominally(80% duty cycle) at the flywheel.

[ThePunisher95]

No I have 28lb injectors from a LS1

[ThePunisher95]

Yeah but at Idle even 19 lb injectors would be enough just to idle. I cant idle rich just lean

[ThePunisher95]

So I dont know wtf to do now. Change MAF(free), fuel filter good fuel pressure, no leaking fpr. Tired of this car already.

[fazm]

So I dont know wtf to do now. Change MAF(free), fuel filter good fuel pressure, no leaking fpr. Tired of this car already.


have you checked the obvious like vacuum leaks, intake leaks, etc?

[ThePunisher95]

Yes sir. Gonna change the fuel pressure regulater tomorrow hopefully and re check for vacuum leaks again while Im at it.

[swirl]

Ok lemme get this straight ur running a stock maf meter with larger injectors?...thats a major problem there. second u need a fmu when running a supercharger to give it more fuel under boost. lemme know if u need help i know a lot about tuning and these cars.

[ThePunisher95]

Ok lemme get this straight ur running a stock maf meter with larger injectors?...thats a major problem there. second u need a fmu when running a supercharger to give it more fuel under boost. lemme know if u need help i know a lot about tuning and these cars.


Stock MAf and bigger injectors would cause a rich condition. Right?


And I havent even boosted on this engine yet. I havent punched cuz I dont need to go into boost to start going lean.

And as soon as I get the Tweecer ill add more fuel. I want to be some were in the low 11's air/fuel to be safe and not to much timing.

[swirl]

technically yes is should richen the car but u dont know the inpedence of those injectors weather its high or low impedence makes a huge diff. Mustangs normally run in the 17ish af at idle but at 2k that isnt normal. The computer may be seeing it getting too much fuel because of the larger injectors and slowing the pulse rate to almost nothing causing it to go lean. You HAVE to fix what u know is wrong and those injectors are wrong. Id put the 19lb injectors back in just to see if that helps it wont hurt