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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: rdallasc on October 15, 2015, 07:19:12 am

Title: spark plug wire help
Post by: rdallasc on October 15, 2015, 07:19:12 am
my son has a 79 gmc 350 motor
running bad so told him and how to change plugs and wires
well, he got everything backwards, so we took off all new wires and need to start over

firing order is printed on intake, but aint shure where to go there and on distriburter
Title: Re: spark plug wire help
Post by: LTZ C20 on October 15, 2015, 12:43:29 pm
This should make it easy.
(http://images.tapatalk-cdn.com/15/10/15/a061ebc4de5edad77aaaf7d5affc26e1.jpg)
Title: Re: spark plug wire help
Post by: rdallasc on October 16, 2015, 07:27:05 am
thanks, now, makeing shure #1 cylinder is top dead center, how do i make shure its rite
Title: Re: spark plug wire help
Post by: Irish_Alley on October 16, 2015, 04:47:32 pm
what i do is pull the number the number one plug and ball up a piece of paper towel and stuff it into the hole. then rotate the engine by hand till you hear the ball pop out this tells you the piston is on the compression stroke, you can then put a screw driver straight down into the hole (if you have it sideways you can scratch up the sidewall) then turn the engine over more till the screw driver comes all the way up and stops then starts to go back down. this is a little past tdc but its close enough to get the rotor pointed in the right direction (at the number one cylinder) and put it all back together and start her up then put her in time. i put mine about 16º atdc with the advance unhooked and it seams to be good. yours might be different but thats about where mine goes
Title: Re: spark plug wire help
Post by: enaberif on October 16, 2015, 07:53:26 pm
what i do is pull the number the number one plug and ball up a piece of paper towel and stuff it into the hole. then rotate the engine by hand till you hear the ball pop out this tells you the piston is on the compression stroke, you can then put a screw driver straight down into the hole (if you have it sideways you can scratch up the sidewall) then turn the engine over more till the screw driver comes all the way up and stops then starts to go back down. this is a little past tdc but its close enough to get the rotor pointed in the right direction (at the number one cylinder) and put it all back together and start her up then put her in time. i put mine about 16º atdc with the advance unhooked and it seams to be good. yours might be different but thats about where mine goes

This all works but I found a 12-14g sized wire in the hole works better for finding TDC once you know your on the compression stroke. Just keep turning till it seats on the wire and don't go any further.
Title: Re: spark plug wire help
Post by: rdallasc on October 17, 2015, 06:41:17 am
thanks guys