xfasteddiex

well i am new to this site i hope i can find some help here i have a 91 gt convertable i just bought & i am gettins 80 miles to a 1/2 tank of gas i checked the pressure reg 32 psi with vaccume on it & about 38 or so with no vaccume & unpluged mas air flow sensor with it running & it tried to die on me so i think it is good i pulled a few plugs out & they look like new only problrm i found as a vac line bad that goes to a port under intake & down to a valve that is marked on diagram as cprv ???it then goes to a canister then to gas tank any ideas ????
thanks in advance
eddie

ACE

Do you notice black smoke comming out of your tailpipes? If your plugs are clean and not real black then your sending unit might just be bad in your fuel pump and giving false readings.

Hollister Hoodlum

shift at 2k instead of 5500[8D]

are you sure your gauge isn't just screwin with you?

WhiteWindsor

You need to fill up your car and set your trip odom. Next time you fill up see how many gallons it holds and divide that into your mileage. Alot of cars will stay around the full mark for longer than they should, then it's like the guage catch's up and then from 3/4 on down it will go fast.

xfasteddiex

it is an automatic & the miles are all highway miles with cruise set at 55 - 65 mph as far asthe black smoke i ain't seen any & the plugs i looked at literally looked like they were just installed how many gallons are these tanks i thought the one on my last 91 lx 5.0 was 12 gal but thats been years ago so i dont remember

WhiteWindsor

I think they are around 15 g. But that doesn't matter as far as how many mile's you go on a half tank if your going by the guage. Just do what i said and you will know you mpg, rather than have to guess.

HemiTCoupe

That is how mine works. 1/2 tank on the gauge, does not mean tank in gallons.

Pat

xfasteddiex

109 miles 8.79 gal = 12.40 mpg dam this sucks i was sure it would get better than my truck 95 chevy ext cab long bed3/4ton diesel but im about 7 mpg less keep in mind i drove the truck 70 -80 on highway i have barley got above 60 with mustang this really sucks

93stallion302

mine is the opposite, mine from full tank 2 half flies down and then slows down drastically at half a tank. but that happens to me, ill fill up the tank reset the trip, and ill get 60 miles to half a tank, and then from half to empty ill get 100-120mpg

xfasteddiex

could it be the maf sensor