Picked up a new Timing Light, and I checked Initial on the 360. With my old Timing light nothing would show, but the new one briefly showed a timing mark at idle 10-12 degrees. I only got to see the mark for a second, and it went away. Why? Is it the cheap 7mm wires (pretty old but new) I bought on Clearance from Rock Auto? I checked the Coil positive in the run position and it seemed a little low with my test light and it seemed a little dim. I suspect there is not enough juice going through the wiring- 74 Duster-Thanks for any help
Timing Mark not showing up??
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Mattax
Just the facts, ma'am
Is the damper marked beyond 10 or 12 degrees?
The timing could be advancing at 800 rpm so at 900 rpm its at 15 BTDC and at 1000 it could be 18*
Another possibility is the lighting in the engine bay versus the light emitted from the timing light. Some of the older ones don't have a strong light source. Can you see the flashes?
The timing could be advancing at 800 rpm so at 900 rpm its at 15 BTDC and at 1000 it could be 18*
Another possibility is the lighting in the engine bay versus the light emitted from the timing light. Some of the older ones don't have a strong light source. Can you see the flashes?
Mattax
Just the facts, ma'am
Some (many?) of the pickups are directional. Suppoose if hte arrow points the opposite way it might not trigger consistantly.
Doubt it has anything to do with the coil. A test light at best can show there is power getting to the coil. It will be low because the power goes through the ballast and more so with the engine off sincepower supply is at 12.6 Volts rather than 14.3 Volts.
Doubt it has anything to do with the coil. A test light at best can show there is power getting to the coil. It will be low because the power goes through the ballast and more so with the engine off sincepower supply is at 12.6 Volts rather than 14.3 Volts.
Dartswinger70
Well-Known Member
A bad plug wire will flash intermittent but you should see and hear the misfire, engine running rough etc.
Kuz
Active Member
Was the timing light flashing consistently after the marks disappeared?
You could have a bad timing light, bad plug wires, bad distributor cap, fouled plug on number one cylinder (or more), or a weak spark in general.
A few things you could do, in no particular order.
Invest in a multi-meter if you don't have one. Test lights can be of limited value when you're trying to determine if you have (for example) 6 volts versus 9 at the coil. How many volts at the coil when running?
Start the engine, clip the timing light pickup to various different plug wires, then aim it at your hand. Don't worry about which cylinder you're clipped to. Are you getting a consistent flash on some cylinders and not on others? Are you getting a consistent flash on ANY cylinders?
What does the number one plug look like?
You could have a bad timing light, bad plug wires, bad distributor cap, fouled plug on number one cylinder (or more), or a weak spark in general.
A few things you could do, in no particular order.
Invest in a multi-meter if you don't have one. Test lights can be of limited value when you're trying to determine if you have (for example) 6 volts versus 9 at the coil. How many volts at the coil when running?
Start the engine, clip the timing light pickup to various different plug wires, then aim it at your hand. Don't worry about which cylinder you're clipped to. Are you getting a consistent flash on some cylinders and not on others? Are you getting a consistent flash on ANY cylinders?
What does the number one plug look like?
Dartswinger70
Well-Known Member
I've used timing lights to check for bad wires just aim it at the valve cover rev it to 2 grand and watch for the intermittent while moving wire to wire.
Mattax
Just the facts, ma'am
And get a tach. The timing is meaningless without knowing the rpm. The Innova multimeter is a moderately priced kit that comes with an inductive pickup that works off a spark plug wire. Or you can sometimes find a tach twell meter at garage sales. They clip onto a coil primary terminal. Works with any standard ignition
Dartswinger70
Well-Known Member
I've seen cheap wires go bad in less than a year, if they are Belden I'd question them.
Try it on no.6. Might have a cracked plug/ bad wire. IS THIS A "dial up" light? I REALLY prefer plain old just plain timing lights, no fancy knobs. In my days in the parts store, I have seen at least 3 that were not accurate
TrailBeast
AKA Mopars4us on Youtube
I currently have a light that is 10 degrees off.
If the initial timing is actually 10 degrees it shows 20.
Dartswinger70
Well-Known Member
How do you know? just try different lights? I actually have a dial timing light and an old 70s timing light etc.
I have an old Timing light from the 80's and it didn't show anything, so picked up a new one and it only ( for about 1 second-twice) showed the mark briefly. I timed it by ear and was pretty close which I'm happy about. Now I'm wondering why it's not coming up. Car has a couple Electrical bugs to work out. Little engine stumble- It won't start sometimes and Headlights come on and then won't work the next try. One time it wouldn't start and I put the test light on the + side to check it ( a little dimmer than normal) and then she started right up??
pishta
I know I'm right....
I second the dial up lights being suspect. I actually got deep into a distributor phase issue before I realized the dial on the tach had moved off zero!
Kuz
Active Member
What happens when "it won't start sometimes"? Does the engine crank over? Or do you turn the key and hear nothing?
Check your battery posts/cables as well as your grounds under the hood.
You should have a ground at the end of the neg battery cable that attaches to front of the cylinder head or engine block. There's generally one at the rear of the engine that runs from the firewall to the rear of the engine someplace (cylinder head, transmission bolt, etc.. I've seen them attached to a few different locations).
Make sure all connections are clean and tight.
Are you getting your 12v power from the coil? That is not 12v. I believe in quality timing lights.
Inertia
Well-Known Member
Try timing it off #6 cylinder.
It also fires at Top Dead Center
It also fires at Top Dead Center
The spark plug wire clamp will only attach one way and give the correct flash. Are you sure you have it on right? Most have an arrow that points toward the spark plug, but some older or cheaper lights do not, so you have to "guess".
Dartswinger70
Well-Known Member
You know, that's a slick trick...
Dartswinger70
Well-Known Member
still nothing? what about the ground to the timing light is the ground good?
So they are old school no dial back? Does the wiring harness plug into the lights? If so, while you have them hooked up, grab the plug and hold it firmly in place see if that makes a difference. Those plugs get loose over time and lose connection.
Yea, they are old school.
Yes, it is running a little rough
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