Author Topic: Timing issue: Stumped...  (Read 11782 times)

Offline kmcbride74

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Re: Timing issue: Stumped...
« Reply #15 on: June 07, 2011, 01:04:16 pm »
i'd suggest it is 180 off, meaning the #1 tdc may be tdc on exhaust stroke.  I'd try this:

Pull your #1 wire off cap and put where #6 is.  Then follow #1 with proper firing order.

if that doesnt work, and you are certain you are getting spark and certain #1 is at tdc when rotor point generally towards #1, I'd look at the fuel delivery and/or carb adjustment / vacuum leak.

Thanks for the replies.  I just checked again, put engine at 8 degress btdc by bumping strater, pulled cap, the metal lead on the rotor is right at the lead on the cap with the #1 wire.  Double checked firing order as well.  Is it possible that the plug going from the distributor to the coil in the cap is backwards?  It appears to plug in one way....

In terms of fuel, carb, vacuum, it ran yesterday before all of this.  I saw some fuel squirt into the carb when I operated the linkage manually.

This dang thing should start!  Is there any logical flaw in my procedure, debug steps or approach here?????

Offline Lt.Del

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Re: Timing issue: Stumped...
« Reply #16 on: June 07, 2011, 01:11:59 pm »
that plug you refer to only goes one way, because there is a clip on it that snaps it in place.

did you try putting #1 plug wire where #6 is and rerouting the following wires?  i still say, it could be 180 off, though you set the mark at 8 btdc, it still could be exhaust stroke. remember, for each fire stroke, the crank/balancer turns twice.

Offline Grim 82

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Re: Timing issue: Stumped...
« Reply #17 on: June 07, 2011, 01:16:07 pm »
Instead of guessing, start from scratch, and forget about the 14 degrees or whatever the cam specifies. Pull the #1 plug and the distributor. Have somebody bump the key with your thumb in the hole until it pushes your thumb off. Then the mark on the balancer should be close enough that you can turn it by hand or with a ratchet and 5/8" socket on the balancer and make the mark line up perfectly with zero on the tab. Then stab the distributor back in and make sure the rotor is pointed at #1. If the oil pump shaft doesn't line up use a long flat screwdriver to turn it until it does. I don't like cranking the engine to get the distributor to drop. Triple check your wires that you have the right firing order and then set the 14 degrees by turning the distributor when it's running.
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Offline kmcbride74

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Re: Timing issue: Stumped...
« Reply #18 on: June 07, 2011, 01:23:19 pm »
that plug you refer to only goes one way, because there is a clip on it that snaps it in place.

did you try putting #1 plug wire where #6 is and rerouting the following wires?  i still say, it could be 180 off, though you set the mark at 8 btdc, it still could be exhaust stroke. remember, for each fire stroke, the crank/balancer turns twice.

I have not tried this yet.  I can/will.  So that I'm clear, you're saying the balancer could tell me tdc, when the number 1 piston is down not up?  i.e. that every other 360 degrees, the #1 piston is up?

Offline Lt.Del

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Re: Timing issue: Stumped...
« Reply #19 on: June 07, 2011, 09:32:40 pm »
the balancer marks will reflect the same way whether on exhaust stroke when #1 piston is up AND fire stroke when #1 is on top.  Crank turns twice for every fire stroke.  Piston comes up twice for every one fire stroke.  Every other rise of piston is fire stroke. You could have rotor pointing to #1 at exhaust stroke.  Put #1 plug wire on #6 and reroute the rest of wires and see what you got. It only takes 5 or 6 minutes to check out.

Offline 1979C20

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Re: Timing issue: Stumped...
« Reply #20 on: June 07, 2011, 10:09:09 pm »
Ever 180° The number 1 piston is UP.
The piston strokes are....

*********
TM U= Timing Mark/Piston UP
TM D= Timing Mark/Piston DOWN
********

> TDC Compression> Fire >TDC Exhaust > Intake \/
|       TM U            TM D        TM U        TM D   |
/\________________REPEAT_________________<


So, pull your distributor out. Pull number 1 plug out. put your finger on the spark plug hole. Bump the engine over until you feel air come out, then bring the piston all the way to the top. that will be TDC compression. Put your distributor in the hole. Bump the key to line up the oil pump shaft(http://forum.73-87chevytrucks.com/smforum/index.php?topic=20821.msg169907#msg169907). Then put your cap on and set your timing. That should solve EVERYTHING. If anyone else thinks otherwise, they will post it. I had the Exact same problem when I fist built my engine because my dad wasnt specific about TDC compression or TDC exhaust. Ran like CRAAAP.

Good luck. Let us know what happens.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 1979C20

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Re: Timing issue: Stumped...
« Reply #21 on: July 28, 2011, 12:50:30 pm »
Just wondering if you got this figured out?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline kmcbride74

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Re: Timing issue: Stumped...
« Reply #22 on: July 28, 2011, 06:13:18 pm »
Just wondering if you got this figured out?

My buddy was able to see the mark on the balancer.  It's good now.  The root cause of my poor running issue was valves too tight!  Too many beers the night we adjusted them before the motor went in. ;)

Offline bobcooter

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Re: Timing issue: Stumped...
« Reply #23 on: July 29, 2011, 02:28:16 pm »
That doesn't sound too good. Hope you didn't run it long like that.
'79 C-20, 350/400, 3:73 gears, 9 leafs and a headache rack
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Offline Dr_Snooz

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Re: Timing issue: Stumped...
« Reply #24 on: July 31, 2011, 10:52:23 pm »
On 454s, the finger over the plug hole trick doesn't work. It's too deeply recessed. I tried using a compression gauge, but that really wasn't helpful either. I finally stabbed the dizzy, started it, pulled the dizzy, flipped it 180 and started it again. The winning position was the one that ran the best. LOL
1989 Chevy Suburban V-2500, 5.7L, TH400

1990 Chevy C-3500 Ext. Cab, 7.4L, 3L80

2009 Chevy Silverado 1500 WT 4WD, 4.8L, 4L60