Timing Problems - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BLACK AND BLUE 67-72 · 01-31-2005, 10:56 PM

I recently swapped the motor into my 70 4x4 and have had a problem trying to get the engine running right. I replaced the distributor and made sure that it was on #1 TDC, the engine will start and run perfectly no miss or sputter except when I hit the gas then hesitation and backfire, when it's in gear and under a load it bogs down when the gas is applied. I have twisted the dist. every which way, if I go counter clockwise it doesn't seem to backfire as bad but when it is shut off it will not start unless it is turned back clockwise. Could a bad spark advance cause this, where it runs fine at idle and acts like that when at higher rpms? Could one work partially, at lower rpms and not higher?

mr402 · 01-31-2005, 11:35 PM

Check the centrifugal advance. Just pull the cap off and make certain it moves freely.

BLACK AND BLUE 67-72 · 02-01-2005, 11:48 PM

Thanks, I spoke to a mechanic friend of mine today and that is what he said also. Hopefully I can get home early enough tomorrow to check it.

Thanks for the reply!!

jhow66 · 02-02-2005, 12:21 AM

You need to reset your dist. -sounds like it is off a tooth or two.

02-01-2005, 11:48 PM	#3
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Thanks, I spoke to a mechanic friend of mine today and that is what he said also. Hopefully I can get home early enough tomorrow to check it. Thanks for the reply!! __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

02-02-2005, 12:21 AM	#4
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	You need to reset your dist. -sounds like it is off a tooth or two. __________________ 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

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01-31-2005, 10:56 PM	#1
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Timing Problems I recently swapped the motor into my 70 4x4 and have had a problem trying to get the engine running right. I replaced the distributor and made sure that it was on #1 TDC, the engine will start and run perfectly no miss or sputter except when I hit the gas then hesitation and backfire, when it's in gear and under a load it bogs down when the gas is applied. I have twisted the dist. every which way, if I go counter clockwise it doesn't seem to backfire as bad but when it is shut off it will not start unless it is turned back clockwise. Could a bad spark advance cause this, where it runs fine at idle and acts like that when at higher rpms? Could one work partially, at lower rpms and not higher? __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

01-31-2005, 11:35 PM	#2
mr402 Registered User Join Date: Jan 2004 Location: Elmira, Oregon Posts: 449	Check the centrifugal advance. Just pull the cap off and make certain it moves freely.



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