My car sucks on gas, im only getting about 250 km out of a full tank. My friend and i worked on the carb and adjusted the idle mixture coz the idle screws were too far out and it seems to have helped a little bit but im thinking this is horrible mileage. The distributor was also loose so we tightened it down and retimed it. Ive also noticed that my car shifts to second gear way too slow and sometimes when im driving it will get stuck in high idle and the car will run at the same speed even if i take my foot off the gas, the speed wont go down. I need some ideas as to where to look, ie: the tranny, carb, anything?

 

with a carb you eill always get worse gas mileage then FI. ITs an easy as 123 there. No carb can be made to get as good mileage as FI. Because in order todo thast, in essence it would not be a carb.

Checking your timing curve i would recoomend first. After a distibutor gets old the weights and their effectiveness decrease as well. Get a mehchanical advance curve kit, and freshen it up.

As far as carb tuning, its all in your settings. Readjusting everything may work for a whil.e But giving everything a bath is great. Rebuild the carb. Clean the invisible gunk out.

 

i forgot to mention that it was a rebuilt carb that i installed Like 2-3 months ago. . But 250 km (155. miles)on a full tank seems to low?

 

rebuilt carbs are sometimes a crapshoot.
also with a rebuilt carb was it your stock rebuilt carb or just a rebuilt replacement?
they might have the jetting a little different then what you need.

 

was a rebuilt replacement

 

does the car sound like it has a miss?
what do the plugs look like and how long ago where they and the wires replaced?
another thing to check is the cap and rotor make sure they are in good working order.

try putting a vacuum gauge on the car and see what vacuum you are reading.


chances are you either have an ignition issue or the carb is out of adjustment or jetting

 

I've had a few stock-stockish LG4 cars, and I would never get more than 300 KM's out of a tank, which is what, like 180 miles to around 45 litres of fuel, or 12 gallons or so. (i never let 'er run empty. What's that work out to, 15 MPG?

The stock LG4 was rated at only 14mpg city / 19mpg highway, and considering I live in north vancouver which is really quite full of hills/mountains and whatnot, 15mpg seems to be right on par with what these cars are rated at.

250km does sound a bit low, but not entirely out of whack. If you're doing alot of short trips, city driving, sticking your foot to the floor, etc, that sounds typical.

Stock, LG4 cars are fairly gutless and suck more fuel than you'd expect for the power you're receiving. 150 horse out of a 5 litre?? WTF??

Luckily, SBC parts are dirt cheap and doubling that HP figure while keeping gas mileage in and around the same is fairly easy with modern cam designs, better flowing heads, and exhaust.