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Old 12-27-2013, 06:53 PM   #1
ozbowhunter
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GAS problem???

while driving the other day the truck started to shudder then die I pulled to the side of the road and after checking the carb and pumping it a few times it started again but not long after the same thing happened I noticed the inline gas filter had a large air bubble in it and it seemed like it was sucking air after getting it started again and getting home it was running fine and the filter was now full

but today the same thing happened again so I removed the inline filter to see if it was leaking I checked the fuel pump after doing this and there is plenty of gas getting to the carb the issue is now the engine will not idle at all and it will only start with the gas pedal flat to the floor
am I looking for a new carb ? or am I missing something? any ideas will be a great help
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Old 12-27-2013, 07:29 PM   #2
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Re: GAS problem???

Sorry guys forgot to say it has a 750 qjet that might help with getting to the problem
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Old 12-27-2013, 07:31 PM   #3
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Re: GAS problem???

I have replaced gas caps before because they wouldn't vent, try taking it off or loosening it, might get lucky. Sometimes what seems like a lot of fuel actually isn't, try a fuel pr check should be around 5-6 psi.
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Old 12-27-2013, 08:10 PM   #4
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Re: GAS problem???

What do I need to check fuel pressure some one said it could be the accelerator pump if that makes sense ?

Last edited by ozbowhunter; 12-27-2013 at 08:29 PM.
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Old 12-27-2013, 09:06 PM   #5
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Re: GAS problem???

Also I am able to keep it running by just holding the engine above idle but if I let it idle it dies

Last edited by ozbowhunter; 12-27-2013 at 09:15 PM.
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Old 12-27-2013, 09:17 PM   #6
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Re: GAS problem???

Look in the carb while it's running. Sounds like it's flooding a little.
Could have something stuck in the needle/seat.
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Old 12-27-2013, 11:07 PM   #7
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Re: GAS problem???

You can use a vacumn/fuel pressure gauge to check fuel pr at the in line at the carb, it does sound more like a needle and seat/stuck float problem as mentioned if it has a hard time idling but runs better off idle. May need to come apart for a cleaning. Know anyone or can you handle it yourself.
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Old 12-28-2013, 05:28 PM   #8
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Re: GAS problem???

http://67-72chevytrucks.com/vboard/s...d.php?t=579621
I had this problem,removed the backflow valve
still have to check float/carb over
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Old 12-28-2013, 06:23 PM   #9
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Re: GAS problem???

And the winner is motornut thans that's all it was removed the little rubber seal and it started and ran perfect the ad news is I just went and bought an edelbrock 1406 carb so will put it on anyway should Make it run nice cant believe a $2.95 filter was the cause of the problem and I got it from advanced autos
Thank you again motornut this is why I love ths forum
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Old 12-28-2013, 09:12 PM   #10
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Re: GAS problem???

Quote:
Originally Posted by ozbowhunter View Post
And the winner is motornut thans that's all it was removed the little rubber seal and it started and ran perfect the ad news is I just went and bought an edelbrock 1406 carb so will put it on anyway should Make it run nice cant believe a $2.95 filter was the cause of the problem and I got it from advanced autos
Thank you again motornut this is why I love ths forum
yes hard to believe "that" will cause that
I tried loose gas cap , didn't help
noticed not a good gas stream inside, and it was a new filter too
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Old 12-29-2013, 03:44 PM   #11
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Re: GAS problem???

I would still check fuel pressure at the fuel line going into the carb, the little backcheck should be easily over come if the fuel pr is correct. I have removed them myself and then shortly after changed the fuel pump because performance just seemed to lack a bit and it helped a lot then reinstalled the check valve filter and all was good, but gues it could ..maybe be faulty, doubt it though.
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Old 12-29-2013, 09:09 PM   #12
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Re: GAS problem???

Going to put a new fuel pump on just to be sure since I'm putting on a new carb thanks for all the help
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Old 12-29-2013, 09:11 PM   #13
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Re: GAS problem???

It may be fine with just the filter, but your right, better to change the pump for what it is worth and forget about it.
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Old 01-02-2014, 05:59 PM   #14
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Re: GAS problem???

I did my pump before,this occured
i'm thinking it's float related,(not holding fuel,straight through when i go WOT)
pulling carb by spring to check,or swap to 4B
or cause of emmisions i've blocked
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