#1 to TDC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**COBALT** · 08-01-2002, 02:54 PM

This is related to my "engine turns but won't fire" topic.

Question: What's stopping me from pulling all the spark plugs, throwing the tranny in neutral, and turning the harmonic balancer by hand to 0 degrees? Why do I have to turn the engine over with the starter?

bigvinnie · 08-01-2002, 02:58 PM

you use the starter to get it close, then turn the crank with a socket on the harmonic balancer bolt til you hit the zero mark on the timing pointer...

I guess you could pull all the plugs, but why?

**COBALT** · 08-01-2002, 03:21 PM

After trying to start thing thing about 1000 times last weekend the plugs are probably fouled. Just a guess.

Gordo · 08-01-2002, 08:45 PM

Be sure to get #1 on the compression stroke if your lookin' to drop your distributor in or check the position of it, because you can have it on TDC and be on the exhaust stroke which will put you off by 180 degrees. You can turn the engine clockwise by hand, if you have the will, and keep one finger covering the #1 spark plug hole, when you are reaching the compression stroke you'll feel it, then continue turning the crank clockwise until the next TDC comes up and you'll have the #1 firing point.

**COBALT** · 08-02-2002, 01:43 AM

Ah, that's right. I forgot about the other half of the cycle. Thanks, gordo. Tomorrow night I get another crack at it.

Blue68 · 08-02-2002, 01:55 PM

I like turning it by hand with the plugs out. Besides being easier, it's a log more accurate and doesn't put undue stress on the crank bolt. And I can always go backwards a little if I go past. Try that with a starter. I also like to feel all the parts go round as I do so. But then I'm a little too involved with knowing how things work.

mtdave2 · 08-02-2002, 02:15 PM

maybe im missing something, but i see this question alot on here.
to me, if you are just putting in a distibutor. i pull #1 plug, put on my remote starter so i can bump the engine.. put my thumb over the plug hole and bump the engine untill i hear air rushing around my thumb. like gordo said.

that means that #1 is on the compresion stroke. then i just put the dist. in so that the rotor is pointing at the #1 post. works everytime.

you dont have to be exactly at tdc to put in the distb. you adjust the fine timing by moving the distrib!

**COBALT** · 08-04-2002, 02:56 PM

I got it running. Turns out I WAS 180 out of phase, and the + wire to the coil (NOT from the starter) was frayed, so I wasn't getting current from the battery after the starter had engaged the engine. I have no idea how that got damaged.

I managed to find the magical spot by turning the engine over to TDC on #1 (I used a hooked scribe to check for the piston through the plug hole--I wasn't getting close by the thumb trick), and then lined up the firing position to #1. For a while I thought the mark on the balancer was wrong. Maybe they put it on incorrectly, but later I found out it was right.

That's when I found out I was 180 out, and that #1 wire wasn't on the #1 post on the distributor cap. Once I got all of that straightened out it would fire, but immediately quit (ah-ha!), so I knew it was electrical. Found the + wire from the battery that was supposed to deliver current to the coil and repaired it. It fired right up. Another 5 minutes later I had it timed.

Thanks guys. New manifold looks way better than the old.

08-01-2002, 02:58 PM	#2
bigvinnie Registered User Join Date: Aug 2001 Location: escondido, ca 92026 Posts: 1,222	you use the starter to get it close, then turn the crank with a socket on the harmonic balancer bolt til you hit the zero mark on the timing pointer... I guess you could pull all the plugs, but why? __________________ '72 short step, 350, 700R4, tilt, ps, pdb, a/c, lowered coils, etc., other work in progress... San Diego, CA 72 Stepside Project

08-01-2002, 03:21 PM	#3
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	After trying to start thing thing about 1000 times last weekend the plugs are probably fouled. Just a guess. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-01-2002, 08:45 PM	#4
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	Be sure to get #1 on the compression stroke if your lookin' to drop your distributor in or check the position of it, because you can have it on TDC and be on the exhaust stroke which will put you off by 180 degrees. You can turn the engine clockwise by hand, if you have the will, and keep one finger covering the #1 spark plug hole, when you are reaching the compression stroke you'll feel it, then continue turning the crank clockwise until the next TDC comes up and you'll have the #1 firing point. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

08-02-2002, 01:43 AM	#5
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Ah, that's right. I forgot about the other half of the cycle. Thanks, gordo. Tomorrow night I get another crack at it. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-02-2002, 01:55 PM	#6
Blue68 Registered User Join Date: Apr 2000 Location: Frisco, Tx, USA Posts: 606	I like turning it by hand with the plugs out. Besides being easier, it's a log more accurate and doesn't put undue stress on the crank bolt. And I can always go backwards a little if I go past. Try that with a starter. I also like to feel all the parts go round as I do so. But then I'm a little too involved with knowing how things work. __________________ http://home.comcast.net/~r.landrum/w...tos.html-.html '68 C-10 LWB, '98 Z-71 350 w/accessories (Serpentine), Edelbrock Performer, Edelbrock 1405 (600cfm) carb, GM HEI, CompCam Extreme 4x4 roller cam, Thorley Headers, Carter Electric Fuel Pump, Vintage Air, 700r4, 3.73, disc brakes and power steering upgrades.

08-01-2002, 02:54 PM	#1
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	#1 to TDC This is related to my "engine turns but won't fire" topic. Question: What's stopping me from pulling all the spark plugs, throwing the tranny in neutral, and turning the harmonic balancer by hand to 0 degrees? Why do I have to turn the engine over with the starter? __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-02-2002, 02:15 PM	#7
mtdave2 newly minted old timer Join Date: Dec 1999 Location: Hudson WI Posts: 3,507	maybe im missing something, but i see this question alot on here. to me, if you are just putting in a distibutor. i pull #1 plug, put on my remote starter so i can bump the engine.. put my thumb over the plug hole and bump the engine untill i hear air rushing around my thumb. like gordo said. that means that #1 is on the compresion stroke. then i just put the dist. in so that the rotor is pointing at the #1 post. works everytime. you dont have to be exactly at tdc to put in the distb. you adjust the fine timing by moving the distrib! __________________ ____________________________________________ 72 c20 longhorn 65k org miles and counting! 69 k10 Suburban Last edited by mtdave2; 08-02-2002 at 02:18 PM.

08-04-2002, 02:56 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	I got it running. Turns out I WAS 180 out of phase, and the + wire to the coil (NOT from the starter) was frayed, so I wasn't getting current from the battery after the starter had engaged the engine. I have no idea how that got damaged. I managed to find the magical spot by turning the engine over to TDC on #1 (I used a hooked scribe to check for the piston through the plug hole--I wasn't getting close by the thumb trick), and then lined up the firing position to #1. For a while I thought the mark on the balancer was wrong. Maybe they put it on incorrectly, but later I found out it was right. That's when I found out I was 180 out, and that #1 wire wasn't on the #1 post on the distributor cap. Once I got all of that straightened out it would fire, but immediately quit (ah-ha!), so I knew it was electrical. Found the + wire from the battery that was supposed to deliver current to the coil and repaired it. It fired right up. Another 5 minutes later I had it timed. Thanks guys. New manifold looks way better than the old. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.



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