running rich,wasting gas,what to do?

[5000cc]

Guys, my car is running rich (13:1) according to dyno result it produce 212 hp at the wheel.I only get about 13-14 mpg and i know that it robbed the power and wasting gas when you are running rich.Is there anything i can do to lean the car just a little.

[fiveohpatrol]

why yes there is. Get an adjustable fuel pressure regulator and go at it. I'd say that setting the pressure at about 37 should do it for ya

[Unit 5302]

Looks like you list 24lb injectors in your signature. Is your MAF calibrated for those injectors? If not, you need to have that done. I'd also check the oxygen sensors, and the temp sensor. What kind of thermostat do you have? Could be your BAP sensor, or perhaps your computer? That is bad fuel economy for sure.

[5000cc]

Thanks,guy for responding.I have adjustable regulator and i used to set the pressure at 37 before until i read the article in 5.0 mag.that they had adjust the pressure to 28 and it gave them more hp.So i adjust mine to 30 right now,don't know if that would hurt me or not. I have changed oxygen sensor already,put 180 degree thermostat.Maf was calibrated to match 24 lbs injector ( i bought it used ) but i don't know what do you mean by BAP sensor i mean where is that? Thanks

[95mustanggt]

I would get to the dyno and adjust the fuel pressure there.

Does anyone think that the 24 lbers could be too much?

Probably wouldn't hurt to check the TPS also.

[Unit 5302]

The 24lb/hr injectors are too much for the combo, but unless something else is setup wrong, they won't kill fuel economy like that. The computer will adjust the injection cycle with information from the MAF and it's database. I've seen a bone stock (well, K&N filter) 1987 SD Mustang GT run great on 24lbers. No fuel economy loss. Still got near 30mpg on the highway with 2.73's.

Since you replaced the O2 sensors, and the MAF is calibrated for 24lb/hr injectors, I don't see those as being problems. The thermostat should be just fine for your application.

The other possibilities that I see are: BAP (Barometic absolute pressure sensor), if it's having major issues or more likely, a vacuum leak, it can cause very poor fuel economy and drivability, the temperature sensor (which could be telling the computer the temp is actually -20* or something if it's malfunctioning), the computer itself not going into closed loop, or a vacuum leak somewhere else.

Have you done a tuneup at all?

[5000cc]

I'vd done tune up last year,you mention about vacuum leak which remind me of last year when i swapped intake to edelbrock. I removed air pump and all plumming after that the car had idle problem for about the first 2-3 mins everytime after you start the car, found out that there was this little plastic red line in the back of intake that i disconnected when i remove plumming line was unplug.So i plugged it and bamm!! idle was back to normal but then i had a lot of oil inside intake so i plugged vacuum fitting from underneath upper intake which connect to PCV and bypass it to the airbox.I still can hear a small noise of hissing from that fitting but since i do not have any idle problem anymore so i ignor it so the leak may come from there like you said. I will try to have my computer calibrate next