running rough after 20 min of driving HELP! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cstm68 · 06-04-2013, 12:24 AM

my 68 with a 327 sat all winter long in the garage and was started about every 10 or so days, i tried to drive it last month and it would spit, sputter and die once i got about 100 yards. i replaced plugs, wires, fuel pump, fuel lines and filter, carb gaskets and vacuum lines. now it runs great for about 20 min then it seems to bog down and the idle gets cut in 1/2. now it is idling all over the board. what else could be wrong?

the carb is about 1 year old

**70cst** · 06-04-2013, 12:32 AM

Fuel? Just a guess...

*Mister-B* · 06-04-2013, 12:37 AM

Try a good gas additive, like Lucas Oil.
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cdowns · 06-04-2013, 06:54 AM

next time it happens take off your gascap to see if that solves the problem

68gmsee · 06-04-2013, 12:41 PM

After you check the above check for debris in carb and/or fuel filters, also there's a possibility of flooding due to sticky gummed up needle valve, even defective vacuum advance or problems with the distributor.

cstm68 · 06-05-2013, 09:44 PM

Took the carb off and dropped it off with the local carb guy, he called me an hour later and told me to drop the tank and flush all fuel lines. Someone someware decided it would be fun to put sugar in my gas tank...
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BADPURPLE70CHEVY · 06-05-2013, 09:49 PM

Quote:

Originally Posted by cstm68

Took the carb off and dropped it off with the local carb guy, he called me an hour later and told me to drop the tank and flush all fuel lines. Someone someware decided it would be fun to put sugar in my gas tank...
Posted via Mobile Device

What???? Man people really have no respect for peoples things. Sorry to hear bud. Might want to invest in a locking gas cap. I have one because there are some mean people out there.

cstm68 · 06-05-2013, 10:02 PM

Quote:

Originally Posted by BADPURPLE70CHEVY

What???? Man people really have no respect for peoples things. Sorry to hear bud. Might want to invest in a locking gas cap. I have one because there are some mean people out there.

Iv got a "cool cap" located in the bed since I relocated the tank. But I'm 99.9% sure I know who the SOB that did it. the thing is they would have had to get into my garage to do it. The only time it been out of the garage since last summer was just for quick spins to keep the tires round and If it was out of my garage i was in it.
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06-04-2013, 12:24 AM	#1
cstm68 Registered User Join Date: Jan 2007 Location: shoreline, wa Posts: 1,565	running rough after 20 min of driving HELP! my 68 with a 327 sat all winter long in the garage and was started about every 10 or so days, i tried to drive it last month and it would spit, sputter and die once i got about 100 yards. i replaced plugs, wires, fuel pump, fuel lines and filter, carb gaskets and vacuum lines. now it runs great for about 20 min then it seems to bog down and the idle gets cut in 1/2. now it is idling all over the board. what else could be wrong? the carb is about 1 year old __________________ 68 swb fleet bagged on 20's 327 with 4 speed http://67-72chevytrucks.com/vboard/s...d.php?t=223308 2014 Chevy 2500hd duramax CCLB

06-04-2013, 12:32 AM	#2
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,365	Re: running rough after 20 min of driving HELP! Fuel? Just a guess... __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

06-04-2013, 12:37 AM	#3
Mister-B Account Suspended Join Date: Oct 2012 Location: Salt Lake City, Utah Posts: 3,331	Re: running rough after 20 min of driving HELP! Try a good gas additive, like Lucas Oil. Posted via Mobile Device

06-04-2013, 06:54 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: running rough after 20 min of driving HELP! next time it happens take off your gascap to see if that solves the problem __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

06-04-2013, 12:41 PM	#5
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: running rough after 20 min of driving HELP! After you check the above check for debris in carb and/or fuel filters, also there's a possibility of flooding due to sticky gummed up needle valve, even defective vacuum advance or problems with the distributor. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...

06-05-2013, 09:44 PM	#6
cstm68 Registered User Join Date: Jan 2007 Location: shoreline, wa Posts: 1,565	Re: running rough after 20 min of driving HELP! Took the carb off and dropped it off with the local carb guy, he called me an hour later and told me to drop the tank and flush all fuel lines. Someone someware decided it would be fun to put sugar in my gas tank... Posted via Mobile Device __________________ 68 swb fleet bagged on 20's 327 with 4 speed http://67-72chevytrucks.com/vboard/s...d.php?t=223308 2014 Chevy 2500hd duramax CCLB



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