Tilley

Just recently bought my second 65 Mustang coupe and new advice on correcting a problem with lousy gas mileage.

The car has a 200 inline 6 with a one barrel carb and I am getting about 10 miles a gallon on easy freeway driving (ave. speed in 65mph). The previous owner said he just had a recent valve/ring job and had replaced the carb.

The car runs okay...not great or smooth, just okay. No oil leaks and the oil is clean. Carb looks clean on outside, and I am running regular unleaded gas.

What should I look for and do to get this pony running smooth and affordable?

What gas mileage are you 6-cylinder lover's getting on your cars.

Thanks for the help....let me know if you need pictures.

blazerdup

Wow that is horrible gas mileage for that engine. I have the same engine, rebuilt about 2 1/2 years ago but it gets closer to 20 MPG on the highway. One time, right after I got it built it got about 29 mpg on the hwy but was kinda skewed. Have you checked the plugs, wires basic tune-up stuff?

rmodel65

what is your timing at? last tune up like said above?

Tilley

I sold my Jeep to afford the mustang and the very next day I had to start my work week. I have two days off to correct this problem before I have to return to work.

What do you folks think I should look at first?

2+2GT

You should be getting 20-25 on the highway. Definitely needs something. Is the distributor advance working? The Loadomatic is supposed to be used in tandem with the Autolite 1100 carb.

Tilley

Loadomatic?

JMD

The Loadmatic is the system Ford used on 6 cyl engines through 67 or 68.

Instead of using mechanical advance in the distributor all advance was provided by vacuum through a special valve built into the carburator, which essentially limits your carb selection.

I recommend going to fordsix.com to research the situation. http://classicinlines.com/Loadomatic.asp

IMO (my guess) is that you have a compatible carb, but possibly the valve is not working just right or the diaphragm in the distributor may be broken.



Ford made it tough to upgrade out of the Loadmatic because the distributor shaft on the later (standard style) distributors is a little bigger.

There are ways to overcome this, but none are both cheap and easy.

I have a Falcon with a 144 6 that I am going to turn a later model distributor shaft down a little and use with a later oil pump (5/16 drive).

On the bright side, the Loadmatic will work ok once it is working right.

Of course it may be that the carb float is just set too high or sticking.

Gun Jam

Hey remember all those people who said they got really crappy fuel mileage by using a 160f thermostat?

perhaps you could check it using a non contact thermometer although due to the cast iron housing the temp lag would probably be enough so you couldn't tell what the hell was going on.

I guess if its not a vac leak or a stuck float or any of the other above great suggestions you could check that thermostat....

just an idea

-Gun

Tilley

Thanks for all the info fella's. Tomorrow I will take a picture of my carb set up so you guys can take a look at it. If I had to take a guess only having spent 10 minutes with it, I would look hard at the vacuum advance. I read the site listed above about the loadomatic. Perhaps this may not be a compatible distributer.

Would installing an electronic ignition instead of the conventional distributer help?

Gun Jam

You could indeed switch the whole system over to electronic ignition BUT it would only help if the primary cause of the issue was ignition related. There are quite a few things that could be the cause.....

That said if you changed the whole ignition system and get a nice distributor AND new plugs and wires AND a new intake manifold with a new modern carb and you set everything up right chances are the problem would be solved...

Or

maybe you smack the float housing once or twice with a screwdriver handle, install a good fuel filter get the same results as above and go about your business usually the solutions for these "major" problems are that dumb

-Gun