Author Topic: Running out of fuel  (Read 1755 times)

Offline AzDarth

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Running out of fuel
« on: September 10, 2018, 02:37:25 PM »
This 1974 GMC 3/4 4X4 was dads until he died and has developed an issue. It's run fine for the past 40 years and just recently started running out of fuel after 20 minutes of driving.....while both tanks are full (I installed a glass filter by the carb). I changed both sending units, 3 mechanical pumps, one electric, eliminated the the tank selector switch still running out of fuel after it gets hot. Back to mechanical A/C Delco original same problem. Replaced all rubber fuel lines and still running out of fuel.

I couldn't run it for long before it runs out of fuel.

Until...... I bypassed the factory fuel lines that run inside the frame rail by the 40 year old headers with strategically run rubber fuel line. Problem solved!!!!! 

Why are the fuel lines suddenly getting so hot the fuel boils on it's way by after all these years?

Side note..... just finished rebuilding the motor on the Hickey Sidewinder winch. Wiring is proving difficult.

Online bd

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Re: Running out of fuel
« Reply #1 on: September 10, 2018, 04:32:16 PM »
Are you sure that the hoses are not just deteriorated to the point of sucking air or collapsing?  Is there an exhaust leak?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Rapid Roy

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Re: Running out of fuel
« Reply #2 on: September 10, 2018, 04:34:11 PM »
Welcome.
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline AzDarth

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Re: Running out of fuel
« Reply #3 on: September 10, 2018, 06:16:42 PM »
I suspected that, replaced all new rubber lines, only thing that cured it was to eliminate the factory SS lines

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Offline AzDarth

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Re: Running out of fuel
« Reply #4 on: September 10, 2018, 06:16:58 PM »
Thanks!!

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Online bd

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Re: Running out of fuel
« Reply #5 on: September 10, 2018, 07:09:48 PM »
Did you change your fuel supplier prior to the symptoms manifesting?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline AzDarth

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Re: Running out of fuel
« Reply #6 on: September 10, 2018, 10:24:26 PM »
Did you change your fuel supplier prior to the symptoms manifesting?
No, not really, Been gassing at the same places for years

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Online bd

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Re: Running out of fuel
« Reply #7 on: September 11, 2018, 09:13:46 AM »
Something changed.  Have you made any changes that could have affected air circulation through the engine compartment?  How many hose nipples on the fuel tank pickups?  Is there possibly a 1/4" fuel return hose missing or restricted between the fuel pump and the fuel tanks?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)