Big Fuel Cons. and hard to start I need Advise

[kurkovn2005]

I have a 96 Jetta and it has around 125,000 miles on it. Ever since I got it. It gets about 21-22 miles per gallon on the freeway. Msn says it should be around 30 for free way. But another thing that is weird about it and hopefully will help me to know the problem, is that when I start the car the starter keeps on spining through until I finnally press the gas and then it starts with alot of burned gas from the exaust. Also once I press the gas if I let it go quickly the car dyes out again. So usually I have to hold the gas for like 3 seconds. But this occurs randomly. Some times it starts ok. But like around three days ago it was really bad. So I really need advise on what to change. I thought to maybe change the O2 sensor since they need to be changed at around 100,000 miles. i got the car at 104,000. So maybe that. But I dont know if that really has any affect on the ignition of the car. Some of my freinds have advise for me to change the fuel ingector. I never heard of anyone changing that. Usually you can just put in fuel injector cleaner or slowly through time go to the 91 fuel that cleans it out too, which I did and it did not help. Also there is the fuel pump but I am pretty sure that it has nothing to do with the ignition. Please help if anyone knows anything about this kind of a problem. I really wanna get the fuel system to work right. And I also have the check engine light always on. I recently changed the spark plugs and the wires. So that is all brand new and works fine. If anyone has advise please let me know. I dont wanna buy a bunch of stuff that I dont need. Thank you.

[denisond3]

I think you may have more than one problem. The engine not firing up until you hold the gas pedal down slightly could be caused by a stuck "idle air control valve", or whatever VW calls that item. This by itself would not cause poor gas mileage however.
Your hard starting could also have other causes, perhaps a bad manifold air pressure sensor, or if your car has one, a bad mass air flow sensor. Its pretty important for the rubber inlet duct running from the air filter to the throttle body to be intact, with no holes or cracks. This could cause hard starting, and poor gas mileage, as could a malfunctioing mass air flow sensor or manifold pressure sensor. A vaccum leak can also make starting and cold running difficult, or a clogged PCV valve.
I think you can take your car to an AutoZone auto parts store, and use their scan device to find out what the Service Engine Light is trying to tell you. It may just want a new O2 sensor, or it could be something else - that might be causing your hard starting and low mpg.

[kurkovn2005]

Hello, I just changed my distributer cap and my roter there and it helped alot. I then took the car to schucks and it gave me one code why my check engine light is on. it is "P0171 System too Lean (Bank 1)". The worker there told me that it is the O2 sensor. But I dont know if that is really what it is. This guy is very young and maybe does not know. Does anyone know what it could be. I have a aftermarket air intake on the car when I bought it. It is a 96 jetta. And I get like -5mpg on it. I really need help. I took apart the air intake and cleaned out all the oil and cleaned the MAF. So if you still have advise, I would really appreciate to know what you have to say.