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mpg is bad :(
https://slantsix.org/forum/viewtopic.php?t=43718
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Author:  1974duster [ Sat Feb 19, 2011 7:12 am ]
Post subject:  mpg is bad :(

hey guy i have been driving my 74 duster and i been keep track of the mpg and i am getting around 10 mpg is that bad ? i do more in town driving than freeway and i have done every thing but the pvc and plug wires.

Author:  Brussell [ Sat Feb 19, 2011 7:21 am ]
Post subject: 

I'm thinking it's bad.

What engine do you have?
What work has been done to it?
Did you ever get figures that are better than this?

Author:  1974duster [ Sat Feb 19, 2011 7:37 am ]
Post subject: 

i have a stock 225 with 1 bbl. as far as work been done to it nothing has really been done to it that i know of. the figure that i have been getting have been like that. i have try octane booster and still did not change, i am going to change the rubber line that go to the gas tank i can smell gas when i am under the car by it hopefully that helps some

Author:  zedpapa [ Sat Feb 19, 2011 8:07 am ]
Post subject: 

do you have an auto tranny? if so, it could be that the stator in the torque converter has seized. one of the symptoms is that it will take excessive throttle to maintain speed.

zedpapa

Author:  ceej [ Sat Feb 19, 2011 8:25 am ]
Post subject: 

While possible, it's unlikely the converter is the problem.
I'd be looking at a good tune up, including valve lash and replacing some hoses and other consumables. If your driving the car stoplight to stoplight for short distances, 10 mpg may be in line. How far are you driving, and what conditions?

One of these days you'll have to come to one of our local wrench parties and get your car the once over.
We've fixed a lot of stuff for folks on this board in Richard's or my driveway. :D

CJ

Author:  Fopar [ Sat Feb 19, 2011 9:00 am ]
Post subject: 

I am retired, so have lots of time to look at stuff.

Richard

Author:  THOR [ Sat Feb 19, 2011 5:30 pm ]
Post subject:  yeah!

Wrenching party!

If I had to guess, I would say slopped timing set. My 71 Dart sedan got 10 before I changed the dead timing set. If you have a vacuum gauge, hook it to the port for choke pull off at the base of the Carb, and run it inside the car. Get it started and go for a drive. Observe the reading on the gauge at idle, acceleration, and cruise.

Watch to make sure that the needle isnt, boinking around. A bouncy or twitchy needle would indicate an intake valve leak, which may be minor enough that you wont notice while its running.

Where is your initial timing set at?

:mrgreen:

~RDE~

Author:  1974duster [ Sun Feb 20, 2011 1:34 am ]
Post subject: 

not sure about what the timing is set at what about wheel bears could that help any?? i do have a vacuum gauge i guess i will have to try that, i do like going for a good drive

Author:  1974duster [ Mon Feb 21, 2011 6:50 pm ]
Post subject: 

what would be a good jet to get for my carb. ??

Author:  ceej [ Mon Feb 21, 2011 7:31 pm ]
Post subject: 

PM Fopar. He's a great mechanic, and knows slants backward and forward. We can't begin to guess what might be causing the trouble without working on the car and testing some of the things that would be suspect.
Fixing random things may get lucky and improve economy, but it's more likely to just be very expensive.
Get some help with it!
:wink:
CJ

Author:  1974duster [ Mon Feb 21, 2011 8:50 pm ]
Post subject: 

i will pm fopar and see what he has to say i was looking around on the internet and i found this web page not sure if it will help but i thought i would post it on here anyways
http://www.walkerproducts.com/_pdf/holley1barrel.pdf

Author:  DusterIdiot [ Mon Feb 21, 2011 9:20 pm ]
Post subject:  Stock?

Quote:
what would be a good jet to get for my carb. ??
Stock 1974 Holley 1945?

Rebuild kit and change jet to #60 and change carb linkage settings to same as 1976 model....

That's a start for keeping economy and a bit more "power"...

-D.Idiot

Author:  1974duster [ Mon Feb 21, 2011 9:46 pm ]
Post subject: 

it is a stock duster, could you send me a picture of the linkage and where can i buy it at

Author:  Ross [ Mon Feb 21, 2011 9:52 pm ]
Post subject: 

after my tuneup on my truck the one time i checked my mileage i was getting 18.1mpg. Thats with one 9 mile hwy trip. rest city driving. Not to mention i drive fairly fast and not gonna lie i do put my foot in it more than i should. I have a manual tranny and 4:10 gears out back. but after i got the carb adjusted that made all the difference in the world :lol: All my tuneup consisted of was pcv valve and grommet, plugs, wires, cap, rotor, carb adjustment, and a bottle of carb and fuel system cleaner. If you havent, id replace the fuel filter too. Hope i helped any.

Author:  newport77 [ Tue Feb 22, 2011 11:28 am ]
Post subject: 

Check the ignition base timing first.
It should be something like 2 1/2 to 5 degrees BTDC I believe not not positive.

Next, check to make sure the vacuum advance in the distributor is working and is advancing the timing.
Then check to make sure the centrifugal advance is working.

These are the first and most economical places to check for something like this.

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