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Do you have the vacuum advance hose unplugged from the distributor? With it connected it may be advanced beyond the 12 btdc that you can see on the pointer tab.
Yes, did have the vacuum advance hose disconnected and capped off from the carb. the car only has 41K miles, I would think the stock balancer would last longer than that before it spin or move. I did paint the timing mark on the balancer with YELLOW caliper paint.
I will re-paint it when I get back to troubleshooting this dilema.
Everybody is blaming the cam timing, balancer, dizzy location, etc. So. What is the possibility that the timing light is not even on the number one plug wire? That would certainly explain some things.
Did you install new plug wires? Maybe off one notch clockwise or CCW on the cap? Can you see the plugwires after they leave the dizzy cap? Some are routed through the motor mounts and are hard to trace to the plug. Number 1 & 3 wires get crossed? You said it idled but how well?
Stranger things have happened to the best of us.
Everybody is blaming the cam timing, balancer, dizzy location, etc. So. What is the possibility that the timing light is not even on the number one plug wire? That would certainly explain some things.
Did you install new plug wires? Maybe off one notch clockwise or CCW on the cap? Can you see the plugwires after they leave the dizzy cap? Some are routed through the motor mounts and are hard to trace to the plug. Number 1 & 3 wires get crossed? You said it idled but how well?
Stranger things have happened to the best of us.
The plug wires were tagged with the white plastic label at the distributor end, when I pulled on the #1 wire from the spark plug end the wire tagged with #1 was the moving. I did that make sure I had the correct wire to clamp the timing light pick up on.
I will start over on my trouble shooting and will make sure I have the correct wire.
you say you turn the dist both ways?
i guess it is way advanced now, and when you retard it it stalls?
my guess is the carb needs the idle set up higher to
allow the retarding of the timing.
understand?
depending on the cam, you may be opening the throttle
past the idle circuit. a whole new issue will pop up.
need to open idle air screws
you need an idle fast enough to run but not so fast as to get the mechanical advance to kick in
good luck
Last edited by calwldlife; Jan 10, 2018 at 09:04 PM.
ok, fool proof method of timing.
turn crank by wrench or starter taps to get on
number 1 comp stroke stopping at the 12 deg
advance mark.
pull number 1 wire at cap and loosely place back in so you can see/hear spark
turn key to run
twist dist until you see hear spark by going back and forth
and then fine tune the position.
If the cam is 180 deg out, and the distributor is also 180 deg out, then you are timed correctly. Rotate the crank through 360 deg and everything is lined up. I think you are going to have to start from scratch by determining exactly where top dead center is. You can do this with a piston stop that you screw in the spark plug hole. You can't do much until you know if your timing marks are correct. And this is what the marks on the cam and crank gear look like when the cam is installed correctly.
An update on the 79 cam dilemma. the way the cam and crank are aligned on this photo is the same way I aligned mine. Today I tried several suggestions provided; the result: No matter what I do the timing mark shows up 180 out (passenger side) of the water pump.
I removed the dist and rotated the engine several times, then I stuff a piece of paper over the #1 cylinder spark plug, bumped the starter until the paper popped; the timing mark stopped a 10 degree BTDC.
Installed dist and aligned the rotor to #1 cylinder, car runs but it back fires through the exhaust when I rev it up. If I rotate dist counter clock wise, it back fires through the carb. so I rotated it clock wise until it does not back fire, curing a test drive it back fires from both carb and exhaust.
going to open is up again and start from scratch, unless someone has another suggestion to try before I begin. thank you for all the help. Oh yeah, I restored another 79 about a year ago, did the same thing. that corvette runs great, I am puzzled why this one a challenge.
You could try a compression test, pretty good bet that if the compression is good, the cam is timed right. What method did you use when you adjusted lifter preload? Go through the firing order again and make sure there are no plug wires crossed. Like was stated earlier, maybe use a piston stop to make sure the balancer hasn't slipped.
You could try a compression test, pretty good bet that if the compression is good, the cam is timed right. What method did you use when you adjusted lifter preload? Go through the firing order again and make sure there are no plug wires crossed. Like was stated earlier, maybe use a piston stop to make sure the balancer hasn't slipped.
I used both methods to make sure the preload was not excessive, first I did the every 90 degree rotation, then tighten all the lose push rods, I went ahead and did the exhaust opening to adjust the intake, then added a half turn before locking the rocker arm. I am positive the balancer did not, because I also made a mark on the pulley to show if the balance has slipped.
Man! I'm confused by all this. Have you moved the timing light to #6? How about moving it to all the other wires to see if your marks at least come into view?
I will say what everyone else is thinking. Pull the waterpump, timing cover, cam sprocket and start over. You don't even have to remove the intake. Pull the dizzy up just far enough to clear the cam gear. Loosen all 16 rockerarms. Turn crank sprocket DOT to 12 o'clock straight up. Cam sprocket DOT at 12 o' clock straight up. Set valvelash, set dizzy #1.
Done.
I will say what everyone else is thinking. Pull the waterpump, timing cover, cam sprocket and start over. You don't even have to remove the intake. Pull the dizzy up just far enough to clear the cam gear. Loosen all 16 rockerarms. Turn crank sprocket DOT to 12 o'clock straight up. Cam sprocket DOT at 12 o' clock straight up. Set valvelash, set dizzy #1.
Done.
I will say what everyone else is thinking. Pull the waterpump, timing cover, cam sprocket and start over. You don't even have to remove the intake. Pull the dizzy up just far enough to clear the cam gear. Loosen all 16 rockerarms. Turn crank sprocket DOT to 12 o'clock straight up. Cam sprocket DOT at 12 o' clock straight up. Set valvelash, set dizzy #1.
Done.
Some timing chain sets have multiple marks permitting you to install the cam straight up, or 4 degrees advanced or retarded. There would be three marks on the crank gear along with three different key grooves on the gear. You can see the three key grooves in the crank gear in my photo, although you can't really make out the three timing marks. The mark you use to time the cam must correspond with the groove used when the crank gear is installed. I hope I've explained that reasonably clearly. Anyway my question is - do you have one of these timing sets, and is it possible you set up the cam using the wrong mark?
Some timing chain sets have multiple marks permitting you to install the cam straight up, or 4 degrees advanced or retarded. There would be three marks on the crank gear along with three different key grooves on the gear. You can see the three key grooves in the crank gear in my photo, although you can't really make out the three timing marks. The mark you use to time the cam must correspond with the groove used when the crank gear is installed. I hope I've explained that reasonably clearly. Anyway my question is - do you have one of these timing sets, and is it possible you set up the cam using the wrong mark?
If the OP did, the IGN timing mark would still show up normal with timing light.
If the OP did, the IGN timing mark would still show up normal with timing light.
Good point. I don't think its likely to be a problem with the cam installation. Its really hard to screw that up. Its got to be a problem with the balancer or the distributor installation.
Some timing chain sets have multiple marks permitting you to install the cam straight up, or 4 degrees advanced or retarded. There would be three marks on the crank gear along with three different key grooves on the gear. You can see the three key grooves in the crank gear in my photo, although you can't really make out the three timing marks. The mark you use to time the cam must correspond with the groove used when the crank gear is installed. I hope I've explained that reasonably clearly. Anyway my question is - do you have one of these timing sets, and is it possible you set up the cam using the wrong mark?
I located the shipping box for the cam and the instruction for the cam installation. the instruction did have the three different option; I did use the stock "O" option since this is bone stock configuration. I did have the "O" on top of each other, my feeling when I did install it in that fashion. It was during a rotation that spread apart. I did a "static" timing on it at 10 degree BTDC. It runs great now after I replaced the plug wires. the backfiring was because of the old spark plug wires.
I located the shipping box for the cam and the instruction for the cam installation. the instruction did have the three different option; I did use the stock "O" option since this is bone stock configuration. I did have the "O" on top of each other, my feeling when I did install it in that fashion. It was during a rotation that spread apart. I did a "static" timing on it at 10 degree BTDC. It runs great now after I replaced the plug wires. the backfiring was because of the old spark plug wires.
