Frigidaire Gas Dryer - heat inconsistent

I just replaced ignitor - but after a full cycle at HOT it still has wet clothes. In two cycles of 70 minutes each it drys.

It starts the gas burner - but I suspect that it shuts off early.

What do I need to fix this?

[FONT=Arial]Before getting into the dryer itself it[/FONT]
[FONT=Arial]would be a good idea to [/FONT][FONT=Arial][COLOR=#000000]thoroughly check the venting and [/COLOR][/FONT]
[FONT=Arial][COLOR=#000000]make sure the outside vent hood is [/COLOR][/FONT][FONT=Arial][COLOR=#000000]fully opening. [/COLOR][/FONT]
[FONT=Arial][COLOR=#000000]A restriction can cause the burner to shut down before[/COLOR][/FONT]
[FONT=Arial][COLOR=#000000]drum comes up to the right temperature.[/COLOR][/FONT]

[FONT=Arial][COLOR=#000000] [/COLOR][/FONT]
[FONT=Arial][/FONT]

I have the entire path clean as a whistle

With damp,cold clothes in the dryer, the flame should stay on till the clothes heat up, more than 5 minutes, if not, you probably have bad gas valve coils.