1990 351W Initial Timing
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New User
Joined: Oct 2003
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1990 351W Initial Timing
Need some help explaining this:
Checked timing with spout connector removed and engine is timed to #7 cylinder.
Using deep notch on damper and surface on timing scale marked "timing". Have checked several books and they all agree that #1 cylinder is passenger side-front, #7 cylinder is drivers side-3 cylinders back, and timing is 1-3-7...
With spout connector reinserted, if I rev the engine the timing notch on the damper backs up(about 30 degrees) instead of jumping forward.
Timing has not been changed since the truck left the dealership when new and it runs fine except for a long crank when cold.
What's going on here, what am I doing wrong, or what don't I understand? Pick any question you want.
Thanks in advance.
Checked timing with spout connector removed and engine is timed to #7 cylinder.
Using deep notch on damper and surface on timing scale marked "timing". Have checked several books and they all agree that #1 cylinder is passenger side-front, #7 cylinder is drivers side-3 cylinders back, and timing is 1-3-7...
With spout connector reinserted, if I rev the engine the timing notch on the damper backs up(about 30 degrees) instead of jumping forward.
Timing has not been changed since the truck left the dealership when new and it runs fine except for a long crank when cold.
What's going on here, what am I doing wrong, or what don't I understand? Pick any question you want.
Thanks in advance.
Senior User
Joined: Apr 2004
Posts: 409
Likes: 0
Don't use the "deep" groove on the balancer, clean it off and you should see the correct mark for TDC, if in doubt, pull #1 (front on pass. side) plug and rotate to top dead center on the compression stroke and look at the balancer for the correct timing mark. Engine is timed with #1 cylinder. Firing order is 1-3-7-2-6-5-4-8. On initial accel. the timing (computer controlled) may very well retard as indicated until rpm stabilizes. Extended crank cold could be due to a number of factors, i.e. dirty throttle body @ butterfly to bore contact area, dirty IAC valve, insufficient fuel pressure, flow, or excessive bleed down,vacuum leaks, excessive secondary ignition losses (corroded coil wire electrodes, excessive spark plug gap, insufficient coil output, etc.), or insufficient injector flow rates, to name a few.
