help...carb issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**'70_402** · 01-21-2005, 02:49 PM

my truck has been running fine lately..untill the last few day when it almost wants to die when i slow down and stop.. but runs fine when going down the road and at full load..(wide open) but i noticed today at lunch that my vacume guage wasn't working and while i was trying to figure that out i heard a "drip..ssssss...drip..ssssss" and i took off the cleaner lid and there was gas dripping out of one of the squirters in the two primary bowls...so there was nothing i could do about it so i put the cleaner back on and then i noticed that there was another leak..dripping on to the manifold from the carb (see pic below) what could be causing this... and now it acts like it is flooded when i go to start it in the afternoons...could this issue be related to the vacume guage? it is running directly from the manifold..not the carb..if not what could these be??

thanks in advance...

Rick

Jimbotronics · 01-21-2005, 02:59 PM

Hey 70' - I've been battling that 'exact' issue for a while now. Mine is caused from tons of crap in the tank, it only takes a spec to cause your issue. I installed a quality in-line fuel filter which I take off and blow out about once a week. Just my thoughts...

**'70_402** · 01-21-2005, 03:01 PM

i did run it out of gas about two weeks ago.. but it just started this earlier this week... plus my tank is pretty clean...(new 5 years ago)

Jimbotronics · 01-21-2005, 03:07 PM

I wish mine was...lol - I've heard several of the board members talk about how filthy the fuel is right out of the pump so if you don't have a good filter on it I'd atleast try it. I even went through the trouble of replacing the carb only for a few weeks to go by and start having the same issue. Now I just make sure that the filter stays clean and so far it hasn't done it again, but believe me I know how frustrating it is..

jhow66 · 01-21-2005, 04:30 PM

Inlet needle not sealing off causing gas to overfill bowl.(piece of dirt under it). It then overflows into carb throat(this is what you see leaking out of throttle shaft in picture).
It is flooded . Try this before removing needles(looks to be a Holley). Remove gas line from fuel pump on the side that comes from tank and plug. Now start engine and run until it runs out of gas. Reconnect line to fuel pump. Start engine. This should wash any dirt or debris that was under needle and seat as needle will be open when gas starts to flow into carb. If you don't have an inline filter install one.

67chevemall · 01-21-2005, 05:01 PM

Maybe the rubber O ring broke on the inlet needle!
Or sometimes the fuel keeps coming from a siphoning effect!
What jhow siad clean out the fuel lines and put on a new filter!
If that all doesn't work rebuild the carb

**'70_402** · 01-21-2005, 05:10 PM

i got two in line filters...i will replace them both.

01-21-2005, 02:49 PM	#1
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	help...carb issues my truck has been running fine lately..untill the last few day when it almost wants to die when i slow down and stop.. but runs fine when going down the road and at full load..(wide open) but i noticed today at lunch that my vacume guage wasn't working and while i was trying to figure that out i heard a "drip..ssssss...drip..ssssss" and i took off the cleaner lid and there was gas dripping out of one of the squirters in the two primary bowls...so there was nothing i could do about it so i put the cleaner back on and then i noticed that there was another leak..dripping on to the manifold from the carb (see pic below) what could be causing this... and now it acts like it is flooded when i go to start it in the afternoons...could this issue be related to the vacume guage? it is running directly from the manifold..not the carb..if not what could these be?? thanks in advance... Rick Attached Images __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

01-21-2005, 02:59 PM	#2
Jimbotronics YA YA Join Date: Aug 2004 Location: Rockledge, Fl Posts: 1,273	Hey 70' - I've been battling that 'exact' issue for a while now. Mine is caused from tons of crap in the tank, it only takes a spec to cause your issue. I installed a quality in-line fuel filter which I take off and blow out about once a week. Just my thoughts... __________________ Jimbo '72 SWB - 350 (frame-off resto in progress - donations accepted) '04 Chevy Avalanche '03 Cadillac CTS (wife's ride) Restoration progress - http://67-72chevytrucks.com/vboard/s...d.php?t=335707

01-21-2005, 03:01 PM	#3
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	i did run it out of gas about two weeks ago.. but it just started this earlier this week... plus my tank is pretty clean...(new 5 years ago) __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

01-21-2005, 03:07 PM	#4
Jimbotronics YA YA Join Date: Aug 2004 Location: Rockledge, Fl Posts: 1,273	I wish mine was...lol - I've heard several of the board members talk about how filthy the fuel is right out of the pump so if you don't have a good filter on it I'd atleast try it. I even went through the trouble of replacing the carb only for a few weeks to go by and start having the same issue. Now I just make sure that the filter stays clean and so far it hasn't done it again, but believe me I know how frustrating it is.. __________________ Jimbo '72 SWB - 350 (frame-off resto in progress - donations accepted) '04 Chevy Avalanche '03 Cadillac CTS (wife's ride) Restoration progress - http://67-72chevytrucks.com/vboard/s...d.php?t=335707

01-21-2005, 04:30 PM	#5
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Inlet needle not sealing off causing gas to overfill bowl.(piece of dirt under it). It then overflows into carb throat(this is what you see leaking out of throttle shaft in picture). It is flooded . Try this before removing needles(looks to be a Holley). Remove gas line from fuel pump on the side that comes from tank and plug. Now start engine and run until it runs out of gas. Reconnect line to fuel pump. Start engine. This should wash any dirt or debris that was under needle and seat as needle will be open when gas starts to flow into carb. If you don't have an inline filter install one. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

01-21-2005, 05:01 PM	#6
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	Maybe the rubber O ring broke on the inlet needle! Or sometimes the fuel keeps coming from a siphoning effect! What jhow siad clean out the fuel lines and put on a new filter! If that all doesn't work rebuild the carb

01-21-2005, 05:10 PM	#7
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	i got two in line filters...i will replace them both. __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY



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