Anyone know how to lean the air/fuel mixture on a 3.4?

[StockV6Cam]

Hey guys, when I got my dyno's done the air/fuel mixture was running too rich. I was wondering if anyone knew a way to cut back the fuel by about 3 to 5 psi? Are there any programmers that will do this on the OBD I computer? Hehe and don't tell me to just get more air going through it! (tiago) [img]tongue.gif[/img]

[1BadAzzGT]

You could always use a fuel pressure regulator, however, it's best to lean your car out via the computer. Do you have a fuel pressure gauge hooked up currently? Just wondering why you're saying that it is running rich? If it's running rich, what is the a/f ratio?

[Wicked 3800 V6]

Joining us from EFA, GT?
It's rwbeasley here.
Welcome!
-Rob

[AMinor65]

You can look at the mini-afc from zzperformance.com. It works with later model 3-wire mafs. I have one, it does work. I'm using it to lean my LTs by 5% right now.

[1BadAzzGT]

<blockquote>quote:</font><hr>Originally posted by Wicked 3800 V6:
Joining us from EFA, GT?
It's rwbeasley here.
Welcome!
-Rob<hr></blockquote>

Hey! Not necessarily joining from anywhere although yes I am a member @ EFA, LS1.com, CamaroZ28.com, LS1tech.com, F-Bodyhideout.com and many other sites [img]smile.gif[/img] I just have lots of time on my hands and try to help out the car community as much as possible.

Funny thing is that on most of the Fbody boards I'm one of the few that's really accepted so to speak.

[viper98885]

I would suggest a adjustable fuel pressure regulator. Also, how long has it been since you changed your O2 sensors. If they are due, that might help. I upgraded my single wire O2's to 3-wire heated O2 sensors. Lemme know if you want details on that project. If you have a high flow exhaust, it's not a bad idea...only setback is that it's kind of pricey.

[OneQuickV6]

When the LS1 guys get bigger cams and need to elan theirs out a bit, they drill the TB blade. it lets in more air without the MAF compensating, thus running leaner. Might get on the z28 or ls1tech board to find out more. That would be the route I'd go!

[viper98885]

<blockquote>quote:</font><hr>Originally posted by OneQuickV6:
When the LS1 guys get bigger cams and need to elan theirs out a bit, they drill the TB blade. it lets in more air without the MAF compensating, thus running leaner. Might get on the z28 or ls1tech board to find out more. That would be the route I'd go!<hr></blockquote>

3.4L V6 does not use a MAF. Considering the fact that the AFPR is only like $70 or so, and all it takes to change the fuel pressure is a turn on the adjustor, I would go this route.

[StockV6Cam]

Well, here's the dyno sheet that tested for the air/fuel.

http://www.fbodytrader.com/hp&af.jpg

So as you can tell I'm runnin' a bit rich. Anyways I have a Vortech FMU sitting in my closet but I think that just dumps in more fuel when there's boost. Where does the AFPR hook up to? The fuel pump?

[viper98885]

Fuel pressure regulator will replace the existing regulator on the fuel rail. You will remove the old one and replace with the new one.

[StockV6Cam]

Can I run an AFPR and a rising rate FMU at the same time?

[Tiago]

<blockquote>quote:</font><hr>Originally posted by StockV6Cam:
Can I run an AFPR and a rising rate FMU at the same time?<hr></blockquote>

yes I do just that.