90 Tercel 3E Rebuilt MPG ideas??

[shieldsdr2]

Hey all! Just thought I would put up a thread for any suggestions on improving the MPG on my Tercel. Reason why is that I bought it with a rod through the block so I rebuilt the WHOLE thing!
I won't go into details, but the everything was machined, replaced, retorqued and rebuilt on it. PLUS I just put in the Weber conversion kit. So all sensors, pumps, belts, rings, seals, gaskets, etc were changed. The exhaust system is new from front to back. The A/T was flushed, torque converter drained and refilled, new rear-main seal, gasket and filter PLUS I used AMSOIL synthetic tranny fluid. So... the whole thing is brand new!
Additionally, the person I got it from had just put new tires, struts and paint job into it so it looks new, drives new and has TONS of pep!!! I could not be happier with this $300 car! With the cost of the car, parts, machine-work and all adds, I figure I am into it for about $1200.
I have only just put the first tank of gas through it. I adjusted the mixture halfway through it and got just over 25mpg for the first tank. I did use 89octane, but the second tank I just filled-up with I just used 87.

I think I have a unique opportunity to be able to test or tryout things that others have passed on due to the age of their engines or cars. This one is not perfect but is just as good as new.

SO HERE ARE THE QUESTIONS:
> "What things am I overlooking to be able to improve the gas milage on this car?"
> "How can I adjust the mixture to the PERFECT place to get the maximum mpg?"
> "Any other mods that you guys have considered for your cars?"

A few things I am about to redo once I get the engine broke-in completely are:
- ReAdjust the valves.
- ReAdjust the timing.
- Change the oil. (Breaking in with reg oil, will switch to semi-synth next, then ultimately to full-syth (AMSOIL)).

ANY other ideas???

Only problem I am currently having is the electric fan is not turning on and I have troubleshot it down to the wiring harness. The relays function correctly with/without voltage, the sensor was replaced again, the fan was tested to battery voltage and functions so according to the schematics it could only BE the wiring. I run the fan on high-heat to keep it midrange when it trys to heat-up, but overall it runs cool. I also made a cooling air bleed port so I am sure that is not the problem too (or contributing to it anyway). If you have any suggestions I am open to them and appreciate them.

Alright. I look forward to your inputs and love this little car and look forward to something around 35mpg. So watcha got??

[Daox]

The biggest thing by far you can do to increase your mpg is drive differently.

That being said there are some mods you can do, it just all depends on how far you want to take it:
- pump tires up to max sidewall pressure
- install a manual trans, autos (especially older ones) get worse mileage especially in city driving
- get low rolling resistance tires
- block part of your grill off (aerodynamics and warms the engine faster)

There is a lot more ideas here: http://ecomodder.com/forum/fuel-econ...ifications.php

[noahthefrog]

If you haven't already done so, reconnect the EBCV, Oxygen sensor and vacuum sensing valve (above the charcoal canister). This will let the computer adjust your fuel/air mixture on-the-fly and give you better mileage. Instructions for doing so are in the guide linked in my signature below - step#9.

I would also suggest getting the snorkel attachment for the weber and put a K&N cone air filter on the end of the snorkel hose. This will give you somewhere to mount the EBCV and bring colder air into the carb which will improve fuel economy and performance in hot weather. I plan to add that to mine once I have the money for it. If you live somewhere that's usually cold, this may not help.

I ended up setting my fuel/air mix to where I got 0.8v from the oxygen sensor when revving the engine at ~3000RPM. Got about 28MPG in 50/50 mixed city/highway driving on my last tank of gas with 89 octane. I drive very agressively and went up and down three mountains at ~75MPH on that tank of gas so your results should be better. The way you drive will have the most obvious effect on mileage, especially with the Weber's ability to use much more fuel (and make more power) than the stock carb. I get ~5MPG difference between aggressive and defensive driving.

Higher octane gas is only helpful/necessary if the engine pings or runs poorly with lower octane gas. Avoid gas with ethanol in it (aka E20, E10, etc) - the 3E motors do not like it and it reduces gas mileage. The original owner's manual that came with my car says not to use any fuel with more than 10% ethanol (E10). Depending on where you live, you might have to buy premium to avoid the ethanol.

Please post anything you come up with for MPG improvement... I am interested to know what else I can try to improve city mileage besides driving slower.

Regarding the Fan - I would run new wiring to each component until it works if I were having that problem. You could also run a wire to a switch on the dash to turn it on manually if necessary.
EDIT: Have you checked to make sure your thermostat works?