Fuel Problems

Hi there! I did a tune-up last week on my 96 grand am 3.1L, because I was only getting about 8 miles to the gallon. I changed the fuel filter, plugs and wires and the pcv valve. The car is running better but I am still
8 miles to the gallon. I dont see a leak. I dont smell a leak. Can anyone help me troubleshoot?

I'd say a possible culprit could be your MAF. Sounds like it could be shot. Buy a new one and try running it with that - I've heard of guys that have gained tons of performance / MPG back just from replacing their MAF.

well, maybe you guys can help me out. I have a 96 grand am 2.4L, and it get bad gas mileage, The only time that it gets good gas mileage is when we are changing our oil regularly, but like right when it hits when the oil is supposed be be changed (every 3,000miles) it starts getting really bad gas mileage. What could be done to get us better gas mileage?

black exhaust smoke?
raw fuel from the exhaust?
Check the vacuum hose going to the fuel pressure regulator and if it has fuel leak on the vacuum hose then the fuel pressure regulator is failing.
Make sure that the ignition coils tips are clean.

No bad exhaust or anything just bad gas mileage. Where do I find the ignition coil tips?

You have to pull the IDI cover and assembly. The coil packs are built into it, and meet your plug tops directly (no wires). That's where the tips are.