100 miles to the tank

[RedStal95]

Alright my gas mileage SUCKS. On a full tank I'm getting a little over 100 miles. I drive my car hard but not that hard.

What could be the problem?

I do have an exhaust leak before the O2 sensors... could this cause it?
If I start my car to build up the fuel pressure and then turn it off my fuel pressure does not drop, so this weeds out leaking injector, and any possible fuel leak by the rails.

Any ideas?

[Macs Stang]

andy what fuel pressure are you running? also, if you have a vacuum leak that would deffinitley cause the car to have shitty milage. also, O2 sensors that have gone bad could be the cause of bad milage as well.

[DNeinstadt]

A vacuum leak (have you unplugged your EGR?) will SERIOUSLY affect your gas mileage.

O2 sensors will also affect it.

Dan

[RedStal95]

I'm running about 42 (vacuum off) fuel pressure. I do not believe I have a vacuum leak. Hmmm maybe I damaged an O2 sensor when I took them out to put in the headers. Isnt there a way to clean them with a propane torch?

edit: if someone has an extra set of used O2 sensors laying around that I could borrow for a week I'd be their best friend I'd hate to spend $150 on new O2's to find out thats not the problem.

[Macs Stang]

andy, i think you can clean the O2's with carb cleaner.

[Drunko McMoppo]

Yea, I've never done it but I'd assume to try cleaning it with an oxy acetyline(sp) torch. Well at least that's how you clean spark plugs. Worst case scenario you have to buy a new one which you'd have to do anyways. Anyone please correct me if I'm wrong.

[Mustangbabe]

Hey andy-
I have the same year mustang as you and went through the same thing last summer. I replaced the obvious like O2s, the fuel pressure regulator, even checked for vacuum leaks, with no luck and found out it was the fuel pump. Dont know if that will help ya out but it fixed my car.

[RedStal95]

Thanks guys I'm gonna try cleaning the o2 sensors.
mustangbabe - i have a walbro 190 in there about 2 years old, i'm crossing my fingers thats not the prob

Andy

[Mustangbabe]

I hope that isn't the problem either! I have had the wierdest things go wrong with my car and I hope yours isn't the same...

[oCancerPatiento]

Im having almost the same problem as you. Im only getting a little more than 100 miles per tank around town. I know mine has the original o2's in it. I put a 190 pump in my car last year but didnt put in an adjustable regulator. Would not having one of these installed make my car have bad mileage?

[Macs Stang]

it could be that your stock regulator took a crap. it as even shittier for me before i got the adjustable regulator on. i got 89 miles on the hole tank.

so far i have about 50 on the tank with a little over half tank left to go, but that is understandable because of all of the messing around on the way to the bbq and then leaving the bbq.

i would recommend a adjustable regulator anyways. pick up a kirban, they are the way to go. don't forget to grab a gauge as well.
-Tim

[oCancerPatiento]

I have a kirban regulator that I bought from kenny. The thing is that I dont know how to adjust it, so I havent put it on yet.

[Macs Stang]

it is really easy to adjust the pressure. did you pick up a gauge and fittings for it?

[oCancerPatiento]

Nope, I was hoping that I could find somebody that had one of those detachable ones they would rent out to me.

[Macs Stang]

i would just get a gauge on there. because you never now if the pressure is dropping or not without the gauge. more of a saftey thing. and that way to, you can tune the car to get some more power. the gauge and the fittings shouldn't cost more then $35