More Poor Gas Milage Help

[miksax]

I posted this question before, but maybe I can be more specific and hopefully get some advice on how to fix this frustrating problem. I have a 91 lx w/120k. It is all stock except k&n filter, flowmaster mufflers, timing raised to 14 and ford racing wires. I drive only in city traffic, w/most trips only being 2 miles or less. I have been getting 10-11MPG and I'm driving it like a grandma. I've checked the air filter and had the car diagnostic tested, and nothing came up. I double checked all of the spark plug gaps and everything seems up to spec. If it helps, there are also two minor additional problems: when the car is warm and at idle, it lopes about 100rpm and there is an occasional quiet "backfire"/"pop" coming from the driver side tail pipe--only at idle. Someone mentioned something about O2 sensors as a possible remedy. Any help would be fantastic, as I'm starting to get frustrated and broke.
Thanks
Mike

 

[crazypete]

Put some seafoam through the motor. Amazing stuff. That will remove the lope. $5

If it doesnt, flip the distributor cap over and see if it needs replacement. Check the plugs too. If not, side gap and index the plugs. Thats about 5-10% milage right there.

run synthetic. Electric fan and parasitic drag removal: underdrive pullies, ac delete, electric fan to remove the clutchfan.

Drop weight. Big one. I got 25 mpg with 3.73's and a carb for goodness sake and my biggest claim to fame was 500 pounds weight reduction. Strip that car.

If all else fails.....you said it's always city driving....well, for city only driving, some steep gears will greatly improve your city driving granny driven milage. 4.10's or 3.73's. Makes the engine work far less to push the car around. You loose milage on the higher speeds when you run out of transmission gearing.

Hope that helped!

Pete

 

[srothfuss]

Also, do you warm up the car prior to driving? It won't help a great deal but a motor that is warmed up will get better gas mileage than a cold one on really short trips. (Not that the idleing will do any better)

I just had 3.73's put in my car and I drive only 15 minutes to work each way. this week I have gotten 300 miles on one tank of gas. My car is bone stock with stock 10 degrees of timing / good tune up including new 02 sensors. That means I am getting around 20MPG...

 

[DTT92LX]

Also remember that the mpg rating is an average. My friend's Prius, a hybrid, has a realtime mpg guage and initial acceleration from a stop gives readings of like 2-5mpg! That's a prius! If you're only going on 2 mile trips in the city, I'll bet most of the trip is accelerating from stops. Just a thought...