b16_destroyer

I installed my MSD 6AL and now my Air Fuel ratio gauge goes all the way lean after 3500rpms at full throttle. I stopped and checked the plugs and the tip is a grayish white (to me that means lean). So I upped the fuel pressure and retarded the timing on the distributor. Still no fix. I turned the fuel pressure all the way to 42psi at idle and it rose to 50+psi under full throttle and still the gauge reads lean.

I have 8AN fuel line from tank to engine, AEM high volume fuel rail, Aeromotive fuel pressure regulator, and a Bosche 405 lph fuel pump. My only guess would be that with the added spark of the MSD, the injectors can't keep up.

If you have any advice please let me know. It sucks having a car that doesn't run right after you've spent a week straight sun up to sun down working on it.

Thanks.

whiterice

So the only thing you changed before the problem is the MSD 6AL?

b16_destroyer

Well, I added a B&M oil cooler and oil line to the turbo (it is plugged for now) and I regapped my plugs to .055.

I hadn't gapped them before and they were like .030. Either way, I was fine before I put in the MSD 6AL.

The gauge will start out rich then after 3500rpms it leans out all the way and then goes blank.

tranceminister

Your running turbo you said? What are you using for fuel management? If your using something like the AFC, just richen the fuel in that rpm band.

b16_destroyer

No turbo. I have everything to turbocharge but I want fix this problem first.

Do you think I need bigger injectors? Everything fuel related has been upgraded except the injectors.

tranceminister

Well, the only problem with going to bigger injectors is that if your using the FMU when you go turbo, it will probably run real rich. Is your fuel pressure normal?

ZexRex

what?? the a/f gauge just reads nothing? i have never seen that, with that high of fuel pressure you should be running real rich. maybe the o2 sensor is bad or something is wrong with the gauge or how it is connected.

Guy-Fast

Those gauges are inaccurate. Check your plugs I highly doubt you are running lean on a n.a motor

leed

Does your engine burn any oil?
That will put some white on the plugs too.....

I just cant see an NA engine running 42psi FP on stock injectors and ECU running lean.