Question: Understanding the Timing Marks on my C4

[DS75]

These are the timing marks on my 1986 C4. They don't quite match what is shown in my FSM. For one there is not rust in the diagram in the FSM.

I think this is how to interpret the marking but if anyone can confirm it would be great:

The valley in front of the hole is 0 degrees. The first peak on either side should be 4 degrees, the first valley to the left or right of those peaks is 6 degrees, and the next peaks are 8 degrees. I've tried to mark 6 degrees before TDC using a sharpie pen.

 

[John Robinson]

According to the Chilton Manual you are right. The first peak is 4 then the valley is 6 then the next peak is 8 etc.

 

[boomdriver]

yes...

it works best if you can find the 6* mark to wipe it off and mark it with a white out or a grease pen. That reflects in the strobe better.
A scrubbie pad and some ajax or wheel cleaner will wipe most of the rust and crud off the marker plate. Got to find and mark the pulley mark to make it easier to see. Be sure to d/c the timing wire up top...

 

[rayquayle]

Yes again and here is a bit cleaner pic for future reference:

 

[DS75]

Thanks, that picture is worth a thousand words. Based on my measurements last night my timing is at 4 deg BTD instead of the 6 deg BTD called out. Time to adjust it and then on to check/replace the spark plugs and fuel injectors.

Yes again and here is a bit cleaner pic for future reference:

 

[boomdriver]

Sure thing that you can benefit from new injectors......FIC is the way to go. Even IF they ohm ok they're still failing in the spray pattern dept gaurenteed..




Be sure to tell Jon that I could use my commission check about now, or I'll start tellin guys to call Dat. otfl