Olds 307 mpg improvement

[Bladecatcher82]

Thanks for all this info! Fox80, I'm sure my carb isn't set correctly! Where can I get help with tuning? I've never really done carb work yet, so I don't know where all these things are that I'm being told to adjust, or how much to adjust them. Any links or sites that will kind of walk me through it, or a youtube vid? Jetsetw31, I'm not where my timing is at now, I haven't done anything with it yet, but I plan to before the winter comes. I'm going to do a full tune up.
As for my carb, it's a 80457-2 it also says 0142 underneath that, and more towards the 45r-312. Sorry, I really don't know much about carbs haha, but I'm thinking it isn't a spread bore. If a new carb is a high recommendation, what should I get, I hear q-jet is better for DD because it is less maintenance, and I don't even care about power anymore, I just want to get what everyone else is getting out of their 307.
As for timing, I hear stock is 20 degrees, and I should tighten it 2 degrees for more power, but will that hurt or help mpg? Another thing I don't know anything about yet, but that's what this sites for, I guess.
And also, I planned on changing my o2 sensor as well, any suggestion on brand? I hear bosch may cause pinging, and ac is the best, opinions?
What is needed for dumping the emissions stuff?
Also, I may not be able to help anyone here with car stuff, but if anyone has any guitar problems, or concerns, or whatever, I'll gladly help.

 

[Clone TIE Pilot]

A Olds 307 Qjet built to the specs of your motor should improve MPGs. Avoid reman units, you want a rebuilt Qjet, never reman. Since your car was a diesel it may not have the computer system or wiring harness installed and aftermarket Holly carbs disable the computer systems anyway since they lack all the factory CCC hookups. So no need to worry about a O2 sensor. Also you should check if you have a vacuum advance or a computer advance dist. A computer advance doesn't work without the computer carburetor. You need to check about your transmission lockup to since that is usually computer controlled. Again not sure how the diesel cars were set up.

 

[Fox80]

If you don't want to spend the money on a new carb, you can find all kinds if videos/articles on tuning a Holley. They are very easy to do, you might need some parts to try, squirter nozzles, power valves, and jets. If you call Holley they can probably give you a really good baseline for your setup, by now a Holley carb has probably been bolted on every motor ever made. If you want to start with the carb leave everything else alone just do one area at a time, that way you can always go back to what you had if all you do is manage to make it run like crap, unless you do WOT runs daily in your car you can run a DD pretty lean without it acting up. Doing stuff like this is how you learn, it's how I learned, do some research it's not hard. Just remember jets control cruise, squirter nozzle is when you touch the pedal, and power valves are for more sustained load. take the a/cleaner off and rev it up you will see the pump shot from the squirter, most carbs are way to rich on that, you drop that four sizes its a big fuel savings everytime you touch the pedal. Like the above post said you also want to make sure you have a stand alone dist. ie no computer hook up, changing mine over to a four pin module and adjustable vacuum can made a huge difference

 

[jetsetw31]

Since your car was a diesel it may not have the computer system or wiring harness installed and aftermarket Holly carbs disable the computer systems anyway since they lack all the factory CCC hookups. So no need to worry about a O2 sensor. Also you should check if you have a vacuum advance or a computer advance dist. A computer advance doesn't work without the computer carburetor. You need to check about your transmission lockup to since that is usually computer controlled.

X2 Clone TIE Pilot. I forgot about the diesel's CCC wiring is not compatible with the gas engine's. Definitely check if your transmission is a lock up. it will have a square 4 prong plug right by the shifter hook up.

you can find all kinds if videos/articles on tuning a Holley. They are very easy to do, you might need some parts to try, squirter nozzles, power valves, and jets. If you call Holley they can probably give you a really good baseline for your setup, by now a Holley carb has probably been bolted on every motor ever made. If you want to start with the carb leave everything else alone just do one area at a time, that way you can always go back to what you had if all you do is manage to make it run like crap, unless you do WOT runs daily in your car you can run a DD pretty lean without it acting up. Doing stuff like this is how you learn, it's how I learned, do some research it's not hard. Just remember jets control cruise, squirter nozzle is when you touch the pedal, and power valves are for more sustained load. take the a/cleaner off and rev it up you will see the pump shot from the squirter, most carbs are way to rich on that, you drop that four sizes its a big fuel savings everytime you touch the pedal. Like the above post said you also want to make sure you have a stand alone dist. ie no computer hook up, changing mine over to a four pin module and adjustable vacuum can made a huge difference

X2 Fox80. I'm not a Holley hater. I just feel spread bore are better DDs no matter the brand. With that said, yeah stick with what you have. If your engine is running smooth your timing isn't important yet. so yes concentrate on tuning the carb. do the simple things first. Like cleaning the carb, making sure your vacuum hoses are in good shape and not leaking.
Honestly, If you can post some pics of the top of your motor. We all can help a lot better with visuals.

 

[Bladecatcher82]

If these don't do the trick, I'll post more tomorrow, I'll take some of the whole engine bay when its light out again.

 

[spidereyes455]

Its hard to tell from the pics but I cant see a vaccum advance can on the distributor . If it doesnt have one there's 90% of your problem right there. If it has a CCC distributor in it and its not hooked up to a computer the timing will never advance from the base setting , yes it will run but it will have no power and your fuel mileage will be in the toilet.

 

[Clone TIE Pilot]

A computer advance dist needs a complete CCC system to work right.