air fuel ratio question

[eclitz88]

Hi i just have a question on how to make my car run more lean. I just installed a air/fuel ratio gauge and it says that im running really rich. Help ###. Thank you

 

[clipto]

Unless you have a SAFC or DSMLink you can't really adjust anything. What's the a/f ratio showing now? Boost leaks can cause rich a/f ratios. Hopefully you have wideband and not a narrowband.

 

[92AWDHX40]

Your gonna have to get a wideband to get an accurate air fuel ratio, i had one of those all it did was blink.

 

[eclitz88]

Alright. Ya its a narrow band with a digital boost gauge. I just didn't know if I could turn my fuel pressure regulator down. I have it set to 55 psi. I have a big 16g turbo with bigger injectors not sure the size or how to tell. But the p.o. told me it had bigger injectors. I just took out all the IC piping and everything. Cleaned it all up. But I'm still going to get a boost leak tester just to be sure.

I know i really want to get DSMLink. Is there anything else I would have to get for the DSMLink to work? Like ECU? Thanks guys your awesome

 

[WES_393]

Your fuel pressure is too high! With the FPR vacuum line disconnected you should have 37psi base pressure (43psi if auto trans and assuming a 1G). So even if the injectors were stock sized, that could contribute to running rich at wide open throttle.

If you have larger injectors and no way to tune or compensate for them, you are definitely running rich. However, your narrowband gauge won't be able to tell you this. When your engine is under boost, the ECU richens up the A/F ratio significantly. There are quite a few reasons for this, but regardless your narrowband is going to read "rich" whether your running the optimal A/F ratio or not. This is why many consider them completely useless. You need an actual wideband air to fuel gauge to make any rational changes.

So I would start by lowering the fuel pressure to the correct point. Then find out exactly what injectors you have, what type of MAF you have, etc. Without knowing these things, your really just running blind. Then get a wideband and look into a tuning system of some kind (such as DSMLink, Ostrich, even SAFC).