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Discussion Starter #1
My gas mileage is still horrible after new injectors. This morning I filled her up for the first time since then and i got 14.6 MPG and 192 miles on a single tank from completely full to gas light empty.

Anyone have any other ideas on why my gas mileage is so horrible?

Pretty much the only use my Z gets is commuting from my college to home twice a week. 15 miles one way, 90% highway, 10% city. I always let her warm up for 5 min before leaving also.
 

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Have you checked the heath of your O2 sensors? Maybe a coolant temp issue? Hole in your gas tank?;) Seriously, I had an issue with a car one time where gas mileage was horrible. It turned out to be a bad gasket around the sending unit that caused fuel to spill out but only when doing left hand turns.
 

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have you run a hot diagnose on the O2 sensors?

you should have at least 5 blinks every 10 seconds per side. If ur not having that then you could be running rich causing your poor mileage.
 

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thats crazy...I shift right about 2k everytime and average around 22-25mpg and around 330 miles to the tank.
 

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Discussion Starter #6
Brand new O2 sensors on both sides, Brand new Coolant Temp sensor. Last time i was under the car, the gas tank bottom was bone dry.

I don't drive the car like an ass either. I know i have a fair sized vacuum leak, but would that constitute mpg's like what I'm having?

Also she is timed right on 15 degrees.
 

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Discussion Starter #7
Also all compression of the cylinders was within 10% of each other last time I ran the test with the lowest compression at like 155 if I remember straight.
 

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what is your fuel pressure like?

and are you TT or NA? your compression numbers seem a bit low if your NA. I checked the FSM, and according to that your ok, but 155 seems low for a 10.5 compression ratio.
 

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Discussion Starter #9
I'm an N/a. And 150ish was just the lowest, all the others were 170ish if i remember correctly

Fuel pressure is 38 at idle I'm pretty sure.
 

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solve that vaccum leak, hot test the O2 sensors, take a look at your spark plugs and if all check out look at other possibilites... tire pressure, stock wheels? (heavier wheels will bring down your mileage), slipping clutch etc...
 

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Discussion Starter #11
Havent recently checked tire pressure. Will do that this weekend. New sparks, New O2 sensors, but will recheck.

Wheels are 18 inch 350 wheels

Also an Auto
 

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then if everything else clears... I'd say your torque converter is dying on you.

Ask around if anybody else is using 350 wheels and saw a drop in their MPG.

I'd say 18's no matter what allow will definitely be heavier than 16's
 

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Discussion Starter #13
torque converter would lead to bad gas mileage? Would it also make a popping noise when going into gear?
 

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the torque converter would lead to poor gas mileage because it acts as your clutch

the popping noise could be a worn tranny mount.

Remember that the torque converter is always "working" so to speak. The moment you release your breaks the car starts rolling if its in gear. That's why your RPM's need to be set higher at idle, so that when in gear the load put on you engine won't shut it down.

So when your torque converter starts to go out, you'll need to raise the rpm's even more to move at your desired speed
 

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Discussion Starter #16
Luminar Wrote:
-------------------------------------------------------
> What plugs are you using? oem ngk pfr6g11 i hope.


Yes sir.
 

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Discussion Starter #17
I seriously hope I do not have to replace the torque converter. My Z is just so hungry. Hungry for gas, hungry for parts, hungry for my time, hungry for my money. =/
 

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If my mind serves me right, Christine was the name of the car that was possesed and trying to kill the girl... kinda like your Z trying to get you aswell =P lol!
 
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