I've been keeping track of my gas mileage lately and calculated that I get 8 miles per gallon. I have a 305 and think I read recently that people here with the same motor were getting 12 mpg or something.

My work is 22 miles each way + some driving around town so I drive about 50 miles a day which means $12.5 per day and over $60 per week for fuel. There is no way in hell I'm going to start driving my plum (purple) saturn station wagon over my elky so I need to fix something.

I have a 305 with an edelbrock aluminum intake and an Edelbrock 4 barrel carb. All of this came on the vehicle when I got it. I rebuilt the carb last year because it was smoking black through the tailpipe which it isn't anymore.

Anything I should investigate? Should I invest in a new carb? The motor seems to run good.

Thanks!

This recently happened to me, but I have everything factory on my 305. I rebuilt the carb, ran great. Then it started to run really bad. Check your oxygen sensor. I'd go ahead and buy a new one and make sure the connection is good. It's on the driver's side in the exhaust manifold. This should fix it, or at least help it. Check all of your vacuum lines too.

You should be getting much better than 8 miles per gallon. The problem could one of many things, but I would start with a complete tune up including replacing the spark plug wires. I would also readjust the carb. Adjust it by the book, if possible.

What kind of transmission do you have? Is it one with a lockup torque converter? If yes, the fact that you no longer have a Throttle Position Sensor (TPS) in the carb (Edlebrocks do not have a TPS), means you never get the benefit of the torque converter locking up. You DO NOT get the resulting slowing of the engine nor the improved gas mileage. It's like running in second gear all the time when you have a 3-speed tranny. To my knowledge, only the computer controlled Rochester electronic carburetors have that TPS. However, I recently saw on this forum that a kit is available that will enable the lock up torque converter without the TPS. That post indicated the kit sells for $170.00

Use the search feature to find that post.

You have received a lot of common sense good advice here. My 1983 350 definitely has an appetite for fuel, and here regular is currently about $2.24 per gallon.
I can spend $10 per week driving my Toyota to work, or $20 driving the Elky. I will drive the El Camino to work once a week and save it for Sunday drives. I think we are fighting a losing battle.
Eric

Don't bother with the oxygen sensor because no Edelbrock carbs, even the Q-Series have feedback provisions. Not having the torque converter lockup will only contribute a little to poor fuel mileage. How do you drive? It sounds as though you are an enthusiast. For many years I did fuel mileage tests on customer cars who complained of fuel mileage problems. In virtually ever case I confirmed much better fuel mileage than what they reported. The fact that you say it runs good leads me to suspect that driver habits might be a large factor. In any case the advice to due a complete tune (check the compression!) is a good start. If you can dynamically test the actual fuel ratio under load (chassis dyno or portable A/F meter) this would help to establish the actual air/fuel ratios. If you can't do this fatten up the primary fuel rods until you get a lean surge then go up one. Also don't overlock the real obvious like a stuck choke, leaking fuel lines or dragging brakes. Good luck.

I'm going to suggest something here that many might frown upon . . . the possibility of a 2-barrel carb setup.

A few years ago, I set up a 350 Chevy with a friend of mine for street / everyday use to go into my 80 Buick Century 2-dr - roughly the same frame and weight as the Elky. The engine had 9.25:1 pistons and 305 heads that I had larger valves put into. We used an intake from a stock 350 / 2 bbl. motor out of a 75 Monte Carlo (it used the older "O" shaped carb as opposed to the more modern "D" shaped ones). I bought a new Holley 2-bbl. replacement carb for the 75 Monte which comes in 450-500 CFM models. The engine was finished off with a Mallory Unilite distributor and a pair of Chevy Ramhorn style exhaust manifolds from a late 60's pickup with real duals and catalytic converters.

This setup screamed on the street and I got 16-22 MPG with a THM 350 trans, depending upon how much I was putting my foot into it. I'm sure if I took it to the track, 1/4 mi. times would suffer in the top end, but I didn't care since we built it for low-mid range torque. For everyday driving and off the line, a 2-bbl. carb is just fine. It may not be as glamorous as the 4-bbl setup, but it was fast and passed emissions testing with flying colors (without having to tweak it on the side of the road in front of the inspection station).

If you want to look into other setups, you may want to try a used throttle-body EFI setup from a pickup (88-98). These came on 305's and 350's and can be retrofitted onto an older engine without too much difficulty. You will need all the sensors, distributor and computer to make it run, but there are also lots of aftermarket goodies to upgrade these once they are in. These setups also improve efficiancy and gas-mileage of the engine. I had a 95 Chevy pickup with this 305, EFI factory setup and that truck got 14-18 MPG - and weighed more than an Elky.

Gas mileage can be overcome with some patience and a little ingenuity. The price of gas is a killer - don't give up that ride . . .

Dan

I think a 2bbl carb is a bad choice for an enthusiast because you can get the same effect with a 4bbl by not opening the extra 2 venturi's until needed, this is not an option with the 2bbl. If you just can't resist it the secondaries can be inactivated very easily; then can be reconnected when gas prices go down (lotsa luck there).

I don't disagree from a "purist" standpoint - the 4-bbl is the way to go. However, I think there is a stigma attached to the 2-bbl and therefore it is under utilized. I don't know if they still do, but Edelbrock used to make an aluminum performance intake manifold for a 2-bbl small block Chevy.

. . . just trying to offer alternatives to the gas guzzling. I do also agree tha a large part of the gas mileage issue is driver habits . . .

Dan

Most folks tell me that a four barrel is more economical, especially if you don't get too heavy on the pedal, so as to use just the primary jets.
Eric

A single 4bbl is best all around choice, two 4bbls are awesome, three 2bbls are nice, 1 2bbl is ok for gramma's Chevelle. Just my opinion.

A single 4bbl is best all around choice, two 4bbls are awesome, three 2bbls are nice, 1 2bbl is ok for gramma's Chevelle. Just my opinion.

i agree

Yes, I must admit, I can be a bit heavy on the pedal which I didn't realize would be that much of a killer on the gas. I did adjust the carb today, I think it was running too rich. I gave each of the adjusters 3.5 turns clockwise until it almost died then back 1.5 turns to stablize it and made it run good but I am still getting black smoke from the exhaust pipe sometimes.

I also wanted to tackle a ticking noise that the car had since I got it. I pulled the drivers side valve cover and turned the engine over manually and checked the lifting rods but none seemed to be loose so I put the tip of a 2.5 foot long screwdriver on the adjusting bolt of each one and put my ear against the handle to listen. Of the 8 rockers number 1 and 3 were ticking loudly. I tightened those two 1/4 turn and that solved the ticking noise.

A friend of mine said that running the motor with the valve cover off should make a big mess and oil should be squirting everywhere but it wasn't and he was surprised to hear that. There was no oil squirting anywhere, everything was oily, there were puddles on top of the rockers and there was oil "flowing" around the channel near the bottom of the springs but no oil was visibly being pumped or squirted anywhere. Should I worry about this???????? Obviously it has been like this for awhile since I bought the truck less than a year ago.

Lastly, last year I could spin a tire from a standstill if I wanted to but this year I can't. Does all of this information seem to fall into line in any fashion?

Thanks!
--Ryan

Adjusting the idle air mixture screws only affects the mixture at idle and slight throttle tip in and has nothing to do with the cruise, high speed or accelerator circuits. That black smoke from the tailpipe could be a carb problem, is the choke functioning properly and is the float level properly adjusted, what is the fuel pump pressure? Is the catalytic converter still on the car? with all this fuel mixture problems it could be seriously plugged. And as for being heavy on the gas pedal--that is the primary reason for poor fuel mileage. You sound like a young fella--just screech the tires only when it can impress someone else instead of just you.
You did good adjusting the valves. As far as oil squirting all over the place--if the engine is worn and the idle oil pressure low it won't make much of a mess. If you see oil around the top of the head that's good; don't worry about it.

Black smoke usually means stuck choke or very rich choke setting. Make sure the choke is not sticking anywhere throughout its range of travel from fully open to fully closed. Also make sure the choke setting is not too rich while it is in operation. Or a failed or mis adjusted pull off solenoid could cause the smoke (rich condition).

[B]
Big Red--Your story is the same as mine--8 MPG--I just put in a NEW ENGINE--then put in a Tornado Gas Saver on top of my carb. I bought a K & N Airfilter--keep 42 PSI in the tires turned off the engine at intersections with lights that exceed 3 minutes in time. Needless to say I have reduced my trips in my elky. I have a 85 305 auto and never run the air. Now I just found out where I lost 22% of my mileage. Yesterday I filled up with 18.5 gallons of gas I figured I went 167 miles all in the city. That is 9 miles a gallon. Before the Tornado and K & N Air Filter it was 155 miles or 8 miles a gallon. After looking at these numbers I told myself there is major problems here. That is the same amount of mileage a v10 engine receives. The one item I believe allot of us over look is the odometer, when figuring out our Gas Mileage. So what I did was go to Map Quest and I typed in my home address and an address some 2.9 miles away. This was my first try so I was going to the post office anyways and Map Quest said it was 2.9 miles away from my home. OK--I first wrote down my current odometer reading and then the odometer reading at the Post Office. Sure enough there was a .66 of a mile discrepancy or 22.75 % . So using this figure 167 X 22.75 is 38 miles. Added to 167 is 205. So my real gas mileage is 205 divided by 18.5 is 11 miles a gallon. Which is still poor but allot better the 8 miles a gallon. I suggest anyone with 7 to 9 miles a gallon gas mileage do the Map Quest progam to figure out the distant and compare that number with your odometer..--Email me if you discover you found where some of your gas was going.. jackboots@earthlink.net

I get real close to 300 miles, mostly highway driving, from a tank of super in my 76. I have a 383 with 10.5:1 KB Pistons, Comp XE268 Cam Kit, Edelbrock Performer RPM heads, Air Gap intake, MSD Ignition 6A ignition setup, DynoMax Shorty cerma coated headers and 2.5" Dual exhaust and a Edelbrock 1411 750 with oversized jets. My tanks is 22 gallons it costs me around 45-48.00 per tank. That is close to 18-20 Mpg the way I see it. It also has a new 700R4 and New 3.73:1 Richmond Gears. Maybe your trying to get water from a rock.

EDIT: :oops: That is more like 13 Mpg for my 383

Strangely if I add octane booster then my mileage goes down. It’s a 4000 Lb or more truck, maybe I'm just fortunate. I still complain about spending that much cash at once just to be able to drive. It’s only about $42.00 to fill up the 93 Pickup but I get only about 17 Mpg from it and it’s a 305 TBI with the L60 transmission.

Its been a long time since I have worked on an el camino, but, I believe the torque converter locks up when you hit a certian gear and mph. You can wire a toggle switch to do this: In the off position it will let the computer lock and unlock the converter. In the 'On' postition, the converter will be locked up, no matter which gear you are in or how fast you are going, well actually, it won't lock in first. It would cost you about $5 to make, who ever spent $170 on it is nuts. I ASSume that we are talking about 1978-'88 model?

I use this in my buick so when I launch it at the track I can lock the converter, it usually shaves .2 off the ET and about 2 more mph.

If you want the directions, I will look around for them.

Hey Vendor Defendor, I would like a copy of the instructions on the manual lockup torque converter switch. If you can find the instructions, please post or email to me at walford1@bellsouth.net. Thanks in advance for the info.