MPG problems...

[DustyR/T]

I have my 3.0 down until Ross delivers my correct pistons, and I have acquired a 2.2 Sundance Auto 93. Now, to me, 210miles to a tank seems low. Even my modded 3.0 w/ cam timing problems made 280 city! I changed cap, rotor, wires, plugs, and timing is 12BTDC. So Any ideas? I'm not as familiar with these engines, but it does start well and idle smooth. Only 80K on the motor and body.

[puppet]

Check for fault codes first. A couple of flaky sensors can cause this. ( O2 ... MAP ... coolant temp sensor)

[jory]

fuel leak? Any fault codes? That is way too low.

[TurboDoctah]

hmmm i get about the same, 200 miles freeway 12 gallons gas 16.6mpg, so i feel your pain.. wish i could help ya.

[DustyR/T]

well, I know there is a problem. And there are no codes. The timing gun has intermittent missed on all cylinders. I'm testing coil tonight. Anyone think it could be the HEP? And how do you test those with a digital multimeter.

[DustyR/T]

Well, I found a broken ground wire to my 02 sensor. I fixed that and it seems to be smoother. This tank is too far gone to gauge my actual gas mileage increase, but I should see an increase. I'm keeping a 10 tank log to make sure I'm getting what I should. I also took the NGK GR4's out of the engine and put the correct RN12yc in it w/ the correct gap. the miss seems to be gone, and like I said, it seems to be smoother and even have a little more pep. But it is too small to be sure right now and I've only driven it once since I fixed it and you know how "wanting to fix the problem" can lead you to believe that you did fix the problem. We'll see.

[tryingbe]

Miles gone divided by gallon used to fill up the tank = Miles per Gallon.

[EliminatorTurbo]

a good place to check is Fuel Economy
look at "View MPG Estimates from drivers like you"
Its under a picture of a Mazda Miata, lower left corner.
Its a valuable tool to see how different driving characteristics equal different fuel consumption. I manage to beat both estimates for my 2 cars (Lebaron/Cougar)

[DustyR/T]

Quote:

Originally Posted by EliminatorTurbo a good place to check is Fuel Economy look at "View MPG Estimates from drivers like you" Its under a picture of a Mazda Miata, lower left corner. Its a valuable tool to see how different driving characteristics equal different fuel consumption. I manage to beat both estimates for my 2 cars (Lebaron/Cougar)

I know what affects mpg, and on my 3Liter, I was averaging at least 280-290/tank. Thats w/ heads, cams, bad cam timing (loose belt), rich as hell idle, 52mm TB, UDP, and 543 trans.

Quote:

Originally Posted by tryingbe Miles gone divided by gallon used to fill up the tank = Miles per Gallon.

And yes, I always use the mileage from the trim meter over the gallons used to achieve my mpgs. I hope I fix this problem soon!

[DustyR/T]

Well....good news. I put the car on a snap on scanner, and my injector pulse widths were 1.7ms in closed loop. Also, the 02 was reading lean, meaning the ECM was trying to richen the mixture. So I swapped 02's and all seems well. The pulse widths went down to 1.1ms, and now it responds. I will keep you all posted with this tanks results.