sweetcoupe
Registered User
what could be the reason for bad gas milage???im at 80 miles and i went through 3/4 of a tank
sweetcoupe said:and she also has been sittin for about a year......ill let ya know how it turns out
thanks
the-big-e said:All kinds of things can go wrong when a vehicle sits for that long......
I am told that the front and rear crank seals can go bad from sitting for that long....
As you see from the responses, it could be a lot of things hwever some things are more likely than others. you need to know some things are right, namely air filter, plugs, wires and fuel pressure. the computer can not know these things so you should ck fuel pressue @ schraeder valve on fuel rail, should be 35 to 45 psi and should hold for long after ignition is off, if not ,leking injector or fuel pump. plugs should be good to about 60k miles 9unless fowled. fuel press is easy to ck, plug & wire installation is harder and often done wrong so unless someone has recently attempted that, don't worry about those. many problems that can occur are not detected by the computer on the car. sensors that can affect mileage are engine coolant temp, nass air flow and oxygen sensors. only an open circuit on these will be seen by comp. and register a code (ck eng light on?) with the exception of the oxygen sensor wich may throw acode whose description reads bank 1 rich all the time which could be caused by things other than the sensor such as bad plug, leaking injector etc. it helps to have either ascan tool or more definitive, abreakout box to allow fast access to pin voltages @ brain. assuming you do not have these ck one at a time w high impedance volt meter. air flow meter is very possible. bad air filter install can allow dust to weld to filament and can often not be cleaned. there are no definitive specs but i have seen many read ~ 1V @ 1000 rpm then should go up linear, ~2V @ 2000rpm and ~3V @ 3000rpm. faulty MAF uusually produce a lower voltage than this as rpm rises. coolant temp return signal probably starts around 2.9V cold and goes down to around 2v hot. again if these sensors lie the brain would have no way to know the true values. O2 sensor voltage is akward to get ( under car) but is ckd by creating a vac leak and then adding propane to intake to produce lean and rich conditions alternately,lean is .1V and rich is.9V. nomally the car should alternate rich,lean ~ 4 to 8 times per sec. o2s are good for around 90k miles. i will ck back to see how you are doing good luck randysweetcoupe said:what could be the reason for bad gas milage???im at 80 miles and i went through 3/4 of a tank