Anyone out there with only 13mpg??

Well, I've gone through about 4 tanks of fuel since getting my first turbo powered car. The first 2 tanks were gone in about 80-90 miles each, about 8-9mpg!! I 86'd the SAFC, and readjusted the TPS, fixed a few vacuum leaks, and now I'm at 13mpg. Still pretty darn horrible if you ask me...

Things I haven't checked yet, that will be checked soon as I have the means to do so:

Fuel pressure (has stock regulator)
Fuel pump (brand, model)
I still have a vacuum leak somewhere, running about 14in, should be around 18-19 with S3 cams, right? I think it might be in the idle control circuit somewhere.
Haven't checked O2 voltages, too lazy, I'm hoping to find a techtom or nProbe to make things easier

If anyone has a "hey that happened to me, here is your problem", let me know. Otherwise, I'll just keep checking stuff till I find it.

Also, every once in while if sitting in traffic, I get a muffled backfire and a smoke cloud comes out the tailpipe. I don't think its oil leaking through the turbo, cause it smells like raw fuel.

Thanks,

Gabe "my car stinks like unburned fuel" Pari

'91 Sentra
T28
JWT 3 bar
Cobra MAF
555 injectors
S3 cams