Hi all, i really want my t/a to be a daily cruiser. I was told that if i go with a 2 bbl carb instead of my quadrajet 4 bbl carb that i would have better mpg.

If i go 2 bbl what all would happen?
Would i still feel the power or speed i do at 55 mph?
and what all would i have to do to change my 4 bbl to a 2 bbl?

Oh and i went to precision tune, had the plugs changed and a pcv valve put in, and they checked out the rest they said primary and secondary ignition systems were A OK.

also if anyone has any fuel saving tips Other than go to a V6 and other than going and buying a dif car, I would be most grateful
=)

I'm willing to change out anything to save fuel. I have a 305 now and i know that if i go 350 it would drink more gas so i know that's out. What else can i do?

thanks all for your feedback and help

 

I assume you have a 305 V8 (LG4). You should be able to get 25 mpg on the highway if it is properly tune. I get 26-27 with mine. 2 bbl will actually get worse mileage. The Computer Controlled 4 bbl that came with your car is the most efficient carb you can get. How many miles are on the car? maybe you need to do a rebuild of the carb.

 

Yes i have a 305 v8 4 bbl carb. I didn't think that if i went to a 2 bbl carb it would make it worse i thought it would make it better.

My mileage is a 5 digit odometer which reads 86067 now being a 84 i naturally thought it meant 186067 but a friend who knows these cars asked did i take up the carpet yet i said yes and he said any rust? i said only rear quarter panel where the spare tire is in the floor. He said mine might be a actualy 86,067 mileage car. I freaked I hope it is =)

Supposedly the carb was rebuilt 2 years ago but i got my doubts. He took my carb and my advanced auto parts carb kit and he said he rebuilt it but i'm not sure.

I just want to get the most mpg i can. If TPI would work i'd do that. I just want any and all mods i can do to get more MPG.

thanks for the help and please keep it coming

 

You may not want to hear this but... The way you drive makes the biggest diffrence. Take off slowly like you have an egg under the gas pedal. and coast to a stop instead of driving right up to stop lights, when you can. And the most important thing keep a close eye on your tire pressure.

A 4 bbl acts like a 2 bbl till you punch the gas!

 

Oh no no that's quite alright
I am the most considerate careful driver that there can be. Never been in trouble with the law etc. I don't do burnouts i never break the speed limit and i never show off to show the power of the car or anything like that. And i never take off like a bat out of hell so to speak.

Someone told me that if i switched to TBI it would give me better MPG. Is this true?

If so i'll fork out the cash and have it changed to TBI. But then i heard bad about TBI. Is this a good move?

Also what other modifications can i have done? Oh and i don't want to have the engine rebuilt because its doing great now

thanks and please keep the help coming
=)
I REALLY appreciate it

 

1) TPI may get you slightly better mileage but it'll take a long time to recoup the cost of conversion.

2) A properly tuned LG4 should average 23-25 mpg. If you're not getting this, it's time to find out why.

3) The 4 barrel qjet will get you better cruising mileage than a two barrel because the primaries on the 4 barrel will be smaller and more efficient (at cruise) than the throats on the two barrel.

4) The ccc-qjet will automatically adjust for best fuel/air mixture at part-throttle and cruise for optimum efficiency (mileage). Don't swap it, it's the best you can do with a carb for mileage.

5) Mods you can do to increase mileage include a free flowing exhaust and intake. These are restrictive on the LG4 and improvements will only increase the engine's efficiency. I'd recommend a dual snorkle cold air intake and headers with 2 1/2 or 2 3/4 inch exhaust. 3 inch may be too large to see the best benefit at cruise/part throttle.

 

Ok I'm a little confused now. I went to precision tune and they replaced my plugs and said everything else was fine on primary and secondary ignition systems which was really great to hear

I know TPI is costly and pretty hard to convert over.. but what about T B I? What is the good and bad about TBI?

I know that's fuel injection and I myself get tired of patting the gas pedal just to get it to fireup everytime. And i'm getting tired of having to press pretty hard to keep my speed right. Its almost impossible to maintain a speed without having to constantly keep applying more and more pressure. Yesterday i was at 55 mph yesterday on a straight road no bumps no curves no nothing. Then i look down and boom it shows i'm doing 50. So i press harder get it back to 55, look back down i'm doing 57 what's going on??

And what is meant by a properly tuned LG4? How can i get it properly tuned?


What is a CCC quadrajet? They make two diferent types?

I'm very interested in all this
Please keep the help and explanations coming

thanks again all

 

CCC = computer controlled carburetor, around here. I believe the factory called it "Computer Command Carburetor". It uses the same overall quadrajet configuration that was introduced in 1966.

It has a couple of settings that can be adjusted from the outside. The throttle position sensor or TPS, is adjusted at idle using a high impedence voltage meter. The idle air bleed, or IAB, is adjusted using a dwell meter with the engine warmed up (in closed loop operation) and idling. Hopefully, Precision Tune knows enough how to check those (although I wouldn't bet the farm on it).

"LG4" is the standard V8 engine model designation. "Properly tuned" means what you've already had checked, plus the carb adjustments above, plus proper timing setting.

 

I think you own the wrong kind of car then. Ever think of a tercel?

 

CCC= Computer Command Control

Evidently you don't have cruise control. And 23-25 mpg would be highway driving. In the city it would be closer to 13-17 mpg depending on average speed and how many stop and go's. So if you average your freeway miles and city miles it would depend on the ratio between the two. If the mixture control dwell is too high or too low for a sustained minute and a half it will turn on the check engine light. If the light is not coming on then you are probably OK and the O2 sensor and computer are in fuel control.

 

I do have cruise control but it went out on me, don't know why or even how to tell how to fix it.

Also i had my valve cover gasket on passenger side replaced and since then the check engine light has stayed on.


Engine on first fireup i always have to pat the pedal about 3 - 5 times then it fires up slowly bubbling sounding then it revs up by itself on idling speed. Finally i have to press the gas pedal one time to stop the high idling speed to bring it to normal and then it shuts off. Then crank again and finally it starts firing right.


Now I would like to know the good and the bad about TBI. I know tpi is costly difficult and a LOT of modifications. But I have heard about TBI but i want to know the good and bad about it.

Is it better than a 4 bbl carb?


thanks for all the help and keep it coming please


Oh and I only want a t/a no other car.

 

Sounds like you desperately need to tune up / rebuild that Q-jet.
It's not as hard as you think (I know what your first thought there was...), a few hand tools and some time.

Switching to FI of any kind will mean you need more sensors and custom tuning, wiring harness, etc. All of which scares the crap out of me personally.

 

Well, supposedly the carb was rebuilt 2 years ago but i got my doubts. He took my carb and my advanced auto parts carb kit and he said he rebuilt it but i'm not sure.

A friend told me of TBI and if its not too hard i'm thinking of going that route.

Also a friend said he could sell me a brand new flow master muffler for 103 incl tax and 50 for installation. Now can this increase the MPG or will only a whole new exhaust system?

 

You haven't yet told us what kind of mileage you're getting.

If you're getting a check engine light, pull the code and tell us what it is.

Highway driving is closer to 27-28 in my experience. I average 22-23, a little lower in winter when the car spends more time in "warm up" mode. Normal driving, no one's waiting for me to get out of the way.

TBI may get you slightly better mileage, especially in colder weather but you may not even notice the diff.

A muffler alone won't help. The restrictions start at the manifold and y-pipe. Hanging a new muffler behind that will only make your wallet lighter (as Sofakingdom would say).

Otherwise I agree with Sonix, although the only thing that scares me is a Tercel.

 

Pull the code? What code? and how do i do that? I'm not knowledgeable of cars at all, just know how to drive this thing, tear down the interior. and that's about it lol

Also how do i figure out the mileage?

And thanks for the info on the muffler. That's something i don't have to spend cash on thankfully =)

 

ooh, you don't know how to calculate your mileage?
Just out of curiosity, how old are you?

Take a spade connector, 14-16AWG, blue, for example, and stick it in your ALDL ports. Top right, and top, second from the right. Car off of course. Look it up for more detailed instructions. Then turn the key to on, don't start it. And watch your check engine light. It'll blink morse code at ya sorta thing. Tell us the codes.

If your O2 sensor is bad, (very common) you'll get crappy mileage.

I think swapping to an FI system is beyond your capabilities, not an insult, the thought of that terrifies me to my core, and i'm doing a restoration on my TA, with a 350 torn down to the block in my garage right now.

 

Sonix i'm 27, i don't know much if anything about cars, and what you just told me what to do i have no idea what you are talking about


by the way how many oxygen sensors are on this thing? Plus if i go to TBI i'll have someone install it for me.

 

I'm kinda tired, sorry for the cop out.
But do a search on "the paperclip trick" or "pulling codes", it's very easy. Easier then programming your vcr.
Vader has posted a few nice pictures to help you out. I didn't have a paperclip at the time, but I had a spade terminal, and it fits perfectly, so I highly recommend it.

I figured only someone younger wouldn't know how to check their mileage, my dad and brother have been doing it, and throwing around the #'s since I was pretty young, but if you're not part of a "car family" then I guess it's all greek right?

1 O2 sensor on your car. Its in the exhaust manifold I believe. It should have a purple wire going to it. Drivers side.
Well, pull the codes, then post them, and we'll tell you what they mean, and how to fix them.

is your check engine light on? or goes on? if not, then checking your codes might be a waste of time.

 

Its cool sonix

I tried the search on here but the search function is out of order for some reason or another. Until it comes up I don't know how to check these code things. I do know one thing, when i look under the lower dash panel close to the pedals and real close to the kick panel, there is a plug hanging down that has a purple wire but i thought it might be a extra accessory that didn't go to the car, just part of the wiring harness that pontiac put on all of these cars.

Is this where i put the paper clip in that plug?
or is it somewhere else?

And how do i check the mileage? My dad was a "semi - mechanic", I guess you could say, he kept all the cars in basic tuneup, antifreeze, add oil, etc. He passed away May 23 2005 the day after my birthday Man, how I miss him But he never taught me how to check gas mileage. Plus i never asked him, never occurred to me until recently when gas prices started getting higher.

Also about the check engine light, it comes on every fireup and stays on till shutdown. I have no explanation to that except a mechanic replaced the passenger side valve cover gasket and since then that check engine light has stayed on.

Thanks for all the help so far everyone
keep it coming please

 

The wire to the O2 sensor crosses over the driver's side valve cover. The sensor is screwed into the exhaust manifold on that side about halfway down. It should have a one-wire plug connected to it.

You'll pull the codes at the ALDL connector, which should be behind a plastic knockout about 1 inch x 2 inches facing forward above your right knee. Pull the plastic cover off and there should be an electrical connector with two rows of connectors (5 or 6 per row-don't make me go look). Use a piece of wire or other conductor to connect the top, two farthest connectors then turn the engine on but do not start. The check engine light should blink once then twice then again followed by any stored trouble codes. (The 12 blink tells you it's in diagnostic mode).

I check the mileage at nearly every fill up. If your trip odometer works use it to record how many miles you drive between fill ups then divide the miles by the amount of gas you put in the next time you top it off. If the trip odo doesn't work you'll have to record the mileage readings and do some subtracting.

Checking your mileage is a good habit to get into. It will usually be the first indicator that something is in need of adjustment or repair.

There's a tech article here on pulling codes and fixing your trip odo but they don't seem to be working now.

 

Have you ever thought about buying a cheap economical car to drive to work and save that low milage firebird for other times. You cant buy a cat and expect it to bark.

 

Ok I saw no one has told you yet how to check your gass mileage. It's simple.. Next time you fill up the tank )Which is about 30 bucks a week for me) Take note and jot down your mileage and how many gallons you put into the car. (about 13 -14 gallons I think) then drive your car to nearly empty and take not of that mileage.

Example

Mileage at fill up; 1,456.067
Fill up tank to: 14 gallons
Mileage at next fill up 1,456. 307
I drove 240 miles on one tank of gas.

So then you take 240 divided by 14 and you get your gas mileage
that gives me a MPG on the freeway of 17 MPG. (Yes mine sucks becuase I need a new exhuast, Manifold leaks really suck down Gas Mileage)

Tips to save gas:

Just cruise.. Who needs to do 75 MPH? Besides, people like to look at Third Gens, give em a nice long look as you cruise passed.
I usually just do around 65 - 70, I don't let my car kick down that much except on hills.

Don't tromp on the gas at lights. Just ease on out. If you are going to slow for someone, they can go around you. this also includes tromping on the gas to get on the freeway.

Check your tire pressure. that alone can save you 30% more in gas.

Don't overload your car.

All these things worked for me. Where I was taking a 1/4 tank of gas in one 30 mile trip, I now use 1/8 for that same trip.

I hope this helps you some on your gas milage.

 

Well, how about we tell him how to calculate mileage correctly:

1) Fill up the gas tank. Take note of the odometer reading.

2) Drive the car.

3) When you fill up the tank again, record the odometer reading and the gallons added to fill it up. Subtract the first odometer reading from the 2nd, divide the result by the number of gallons you added to fill it up the 2nd time (how much it took to fill it up the first time is irrelevant).

I keep a little spiral notebook in each of my vehicles and keep track of the odometer reading and gallons added each time. If it is not filled, the mileage is not calculated until the next time it is filled. Then, the gallons added between fill-ups and the miles between fill-ups is used - otherwise, you won't get accurate economy readings.