5.7L - Ignition Timing Confusion

Looks normal. Use a timing light that has a degree wheel or a digital one. Put the light on 8 degrees and line up that long groove on balancer with the mark on the cover.
 
That all looks like the timing marks on my 4.3. You mention when you tried to time it, the tab moves up and down the balancer -- do you mean when you actually try to time it with the light and the marks are bouncing around? You do know that you have to put the ignition in base timing mode when you set the timing - if you don't the timing will be moving around due to the advance.

Thunderbolt V
1. Connect timing light to number 1 spark plug. Connect timing light power supply leads (if applicable)
to 12 volt source.
2. Connect a shop tachometer to engine.
3. Using a jumper wire, connect the ignition system
timing lead “13” (PUR/WHT wire) to a good engine ground (–). This locks the ignition module
into the “Base Timing Mode”.
4. Start engine and run at normal idle speed. Allow
engine to reach normal operating temperature.
5. Aim timing light at timing tab, located on the timing
gear cover and crankshaft torsional dampner.
6. Adjust timing using the conventional method.
IMPORTANT: Be sure to disconnect the jumper
wire from the ignition system test terminal before
attempting to resume normal operations. If the
jumper wire is left in place, the ignition module
will operate in the “Base Timing Mode”. This
means that the additional timing advance features would not function.
7. Make sure that the distributor has been tightened.
Remove the jumper wire from the timing terminal.
8. Stop engine and remove timing light
 
scoflaw said:
Looks normal. Use a timing light that has a degree wheel or a digital one. Put the light on 8 degrees and line up that long groove on balancer with the mark on the cover.
Click to expand...

Cool, will do! I have a new digital timing light w/ a tachometer coming in tomorrow.
 
If it truly is being locked in base timing mode correctly and you are still getting a high fluctuation at the pointer while trying to time it, you likely have a badly warn timing chain. You can roll the crankshaft back and forth a bit by hand to see how much movement you get before the distributor moves.
I also have a 5.7MCM of same s/n range. It does not have the second knock control module which would lead me to be more conservative with the base timing. It does not fluctuate when locked in timing mode and is set at 10.
 
Hey Bill, yes you're correct. I was a bit confused at first because I expected the timing marks to be "fixed" while I searched for a moving indicator line/ indent. I didn't realize at first that the pointer in the photo that I uploaded was indeed the actual pointer lol I did make sure to put the ignition in base timing mode but will be taking another crack at it this weekend to get everything straight.

Quick question regarding the jumper wire... Does that need to be removed with the engine still running after I set the timing or can I shut it down & then remove?
 
Nitro15 said:
Hey Bill, yes you're correct. I was a bit confused at first because I expected the timing marks to be "fixed" while I searched for a moving indicator line/ indent. I didn't realize at first that the pointer in the photo that I uploaded was indeed the actual pointer lol I did make sure to put the ignition in base timing mode but will be taking another crack at it this weekend to get everything straight.

Quick question regarding the jumper wire... Does that need to be removed with the engine still running after I set the timing or can I shut it down & then remove?
Click to expand...

On mine I use a jumper to ground it to one of the screws on the carburetor joke. I don't think it matters, but I usually connect / disconnect the jumper with the engine off.
 
Cleaning up the harmonic balancer and highlighting the numbering with white out (or something similar) will help in seeing the numbers.
 
Nitro15 said:
Quick question regarding the jumper wire... Does that need to be removed with the engine still running after I set the timing or can I shut it down & then remove?
Click to expand...
You can just shut it down and remove the jumper wire.
 
Update: I reset the timing this past Saturday using the suggestions that all of you provided & wanted to give a huge thank you. It turned out be very straightforward & the engine definitely seems to be running a lot better. It now starts on the first or second try & operates a lot smoother at lower rpms, especially through all of the no wake zones throughout the local canals. My dad & I were also able to replace the power steering cooler which had rotted away at the hose inlets causing fluid to leak into the bilge. It was a huge mess but I collected all of the fluid into a bucket & brought it to a local recycling center. Thanks again guys, I owe you one!
 
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