Author Topic: MPG  (Read 11127 times)

Offline Irish_Alley

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Re: MPG
« Reply #15 on: April 05, 2009, 01:46:30 am »
with my 86 c10 not sure of ratio but it had a 350 and 350t i was getting 12mpg of the cheap gas and 14mpg at the high end gas pumps. now with the same motor in my 79 k20 i get about 8. just took the carb apart, its a Holley 640 or something i know its a 600. didn't rebuild, just took it apart to clean. cause i noticed a lil rust in the fuel filter so i figured i had some extra gaskets just laying around. when i took the secondary cover off it had been dry so long it had corrosion building up in it. not sure if that hurt or help, I'm sure it hurt the mpgs
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Offline cwilson jr

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Re: MPG
« Reply #16 on: April 05, 2009, 11:00:52 am »
What diff gear(s) do you have?

i have the standard axle ratio code on the options list.  does anyone know what that is off-hand anyways?


something else i noticed is when i was letting it set for a long time before i moved, i would start it up weekly and let it run for a while in park.  i then would have to eventually give it gas (still parked) to keep it from getting over the 210 mark, which i always floored it to kick down the rpms.  i forget what this is called on the carb engines.  anyway it would sound fine.  the other day while driving i pretty much gunned it from a slow pull out and while it was floored, it sounded horrible and like it was choking.  the air filter is pretty new.  could this be a bad cat?  is there a way i could tell this?

also does anyone have any ideas with this?

Offline TexasRed

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Re: MPG
« Reply #17 on: April 05, 2009, 11:09:11 am »

something else i noticed is when i was letting it set for a long time before i moved, i would start it up weekly and let it run for a while in park.  i then would have to eventually give it gas (still parked) to keep it from getting over the 210 mark, which i always floored it to kick down the rpms.  i forget what this is called on the carb engines.  anyway it would sound fine.  the other day while driving i pretty much gunned it from a slow pull out and while it was floored, it sounded horrible and like it was choking.  the air filter is pretty new.  could this be a bad cat?  is there a way i could tell this?

also does anyone have any ideas with this?

Could be an accelerator pump issue. Have you checked the output of the accelerator pump?