Problems going lean.. PLEASE help!

[kjzstealth]

I had a hotwired factory pump and was running lean at 12 psi, so I installed a walboro fuel pump.

It ran awesome for one drive, but when I stopped, my car was smoking from the speedometer sensor. I got it unplugged and put everything back together which, of course, reset my ECU.

Now it is running lean again. Anything past 9 psi and my AF goes over 12:1.

I have had to replace one engine and I don't want to have to do it again because of this.

Any ideas on why this would be happening?

[Trab]

Have you tried changing your fuel filter? I doubt this is it but would be a good thing to do. Also maybe look into trying out another FPR.

[Atrosity]

Are you able to post up your datalogs?

[CoreyB]

Boost leak ?

Edit : Never mind, that would make you rich.

[91STT]

Have you checked fuel pressure yet?
When you installed the new FP did you make sure the O ring did not "fold up" on you.
This happened to me.
It was not lean after it was installed but become lean after I did a few WOT passes while adjusting my boost controller.
In any case, check your fuel pressure first before going on to anything else.
At idle with the vacuum hose connected to the FPR you should get about 34 psi and without vacuum you should get 43-45 psi.

[x2xtreme360]

Best thing is to post a log if possible.

However, start looking into the FPR and filter as possibilities. Think about adding a FP gauge to your setup.

[kjzstealth]

actually I am on the stock FPR still. I dont have any way of posting my logs. I put a cheap fuel filter on it before I replaced the pump, but I just bought a Mitsu one to try that.

Could the fuel pump overrunning the stock FPR be doing this? I thought that would make it go rich at idle.

[94PearlwhiteTT]

Are you running stock 9b's? What are you using for fuel management? Might want to check and make sure your settings on it are the same as they were when it was running good.

Also as stated, knowing what kind of FP your dealing with would help you out a lot.

[91STT]

check the voltage at the pump just in case to make sure that you are get sufficient voltage.
I know you have a hot wire set up, but check it anyway, you need to eliminate all possibilities.

[x2xtreme360]

actually I am on the stock FPR still. I dont have any way of posting my logs. I put a cheap fuel filter on it before I replaced the pump, but I just bought a Mitsu one to try that.

Could the fuel pump overrunning the stock FPR be doing this? I thought that would make it go rich at idle.

Overrunning the pump would make you rich, as you mentioned.

Stock FPR's fail all the time... it still could be the fpr.