i need help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**truckdude239** · 04-12-2009, 01:25 PM

okay guys i am tired of pulling ym hair out i'm to the point i will pay someoen to help me with my truck. i tried timing the truck it was 18 degrees so i turned it back to 8 degrees where it is suppose to be and i can not get it to run right it pops back though the carb at 8 degrees btdc. if ym vavles are 2 tight will ti cause this?

71chevytruckguy · 04-12-2009, 01:32 PM

If its backfiring thru the carb when ya step on it, it needs more timing. If it was running good at 18*, why did you change it? Chris.

71 super · 04-12-2009, 01:40 PM

The outer ring on your balancer could have slipped causing the mark to be off and thus causing your settings to be off. You can solve this in a couple of ways- get a timing tape- Mr Gasket sells on with instructions and check you mark. Test the motor for tdc and check that against the mark on the balancer you have. Buy a cover from transdapt that has the mark perm. scribed into it so if the balancer had slipped the mark is still right, or buy new balancer. Are you sure that the balancer is right for the engine? How many miles does the engine have? Timing chain might be giving up as well...

**truckdude239** · 04-12-2009, 01:48 PM

the balancer is new the truck desesils at 18 degrees./ motor has around 100 miles on it

**LockDoc** · 04-12-2009, 03:07 PM

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I'm with 71 super on his suggestion of manually setting the engine on TDC and see where the timing mark on the balancer is located. I would suspect that you may have the wrong balancer if it is new. The balancer may have slipped even though it is new also. If the timing mark on the balancer is off when you manually set TDC get the timing tape and apply it to the balancer so "0" is correct. I need to do this to the '69 BB because the balancer has slipped. You may be able to get the timing tape at your local auto parts store, call around.

LockDoc

**truckdude239** · 04-12-2009, 09:35 PM

intake picture

Longhorn Man · 04-12-2009, 10:09 PM

What grade fuel do you have in the tank? Very possible that your engine needs the 18 degrees, but with higher octain fuel. Dieseling is a sign of too low a grade of gas.

**truckdude239** · 04-13-2009, 06:40 AM

got 87 in the tank.motor is a stock 305 bored 30 over , stock cam

04-12-2009, 01:25 PM	#1
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	i need help okay guys i am tired of pulling ym hair out i'm to the point i will pay someoen to help me with my truck. i tried timing the truck it was 18 degrees so i turned it back to 8 degrees where it is suppose to be and i can not get it to run right it pops back though the carb at 8 degrees btdc. if ym vavles are 2 tight will ti cause this? __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

04-12-2009, 01:32 PM	#2
71chevytruckguy Registered User Join Date: Jul 2005 Location: Kernersville, NC Posts: 599	Re: i need help If its backfiring thru the carb when ya step on it, it needs more timing. If it was running good at 18*, why did you change it? Chris. __________________ its a work in progess. 71 c-10 lwb, in the middle of frame off restoration. 69 c-10 swb, drag truck, 406 sbc, balanced, comp 292 cam, ported, polished, gasket matched, and bowl blended pro comp 210cc heads, 2.02/1.60 ferrea valves,1.6 roller rockers, re curved hei with msd 6al box, 2-step rev limter, accel 300+ wires, ported victor jr intake, holley 750 double pumper carb, dynomax 1 5/8 headers, 4 spd munci m-20 with super case and iron midplate, mr. gasket vertigate shifter, 5.38 pro gears with full spool, 33 spline moser axles and c-clip elimators, line-loc, 5 gal fuel cell, holley blue pump. 7.807 @ 88.37mph 1.60 60FT 80 g-20 van, tow rig, cammed 305, th350, 10 bolt 88 jeep wrangler, dd, 258, ax-15 swap, 4.5" lift, 33x12.50's, lockers, 3.55's

04-12-2009, 01:40 PM	#3
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,080	Re: i need help The outer ring on your balancer could have slipped causing the mark to be off and thus causing your settings to be off. You can solve this in a couple of ways- get a timing tape- Mr Gasket sells on with instructions and check you mark. Test the motor for tdc and check that against the mark on the balancer you have. Buy a cover from transdapt that has the mark perm. scribed into it so if the balancer had slipped the mark is still right, or buy new balancer. Are you sure that the balancer is right for the engine? How many miles does the engine have? Timing chain might be giving up as well... __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle Last edited by 71 super; 04-12-2009 at 01:41 PM.

04-12-2009, 01:48 PM	#4
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: i need help the balancer is new the truck desesils at 18 degrees./ motor has around 100 miles on it __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

04-12-2009, 03:07 PM	#5
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,772	Re: i need help - I'm with 71 super on his suggestion of manually setting the engine on TDC and see where the timing mark on the balancer is located. I would suspect that you may have the wrong balancer if it is new. The balancer may have slipped even though it is new also. If the timing mark on the balancer is off when you manually set TDC get the timing tape and apply it to the balancer so "0" is correct. I need to do this to the '69 BB because the balancer has slipped. You may be able to get the timing tape at your local auto parts store, call around. LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 04-12-2009 at 03:09 PM.

04-12-2009, 09:35 PM	#6
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: i need help intake picture Attached Images __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

04-12-2009, 10:09 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: i need help What grade fuel do you have in the tank? Very possible that your engine needs the 18 degrees, but with higher octain fuel. Dieseling is a sign of too low a grade of gas.

04-13-2009, 06:40 AM	#8
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: i need help got 87 in the tank.motor is a stock 305 bored 30 over , stock cam __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube



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