20+ year old front loader.

Starts just fine with a new igniter, but after a few minutes igniter lights up, but flame does not start. The coils were replaced approx a year ago. Verified gas flow is good, and exit duct clean of lint. Ohmed out the temperature switch by the flame and it appears Ok relative to schematics.

Any suggestions? Could it be a 'new' deffective coil assembly?

Do you get pilot? If so, for how long?

Do you mean do I get a flame once the igniotor lights up (there's no 'pilot' light)? - in the beginning yes, at least for a while, but then after it turns off once or twice I do not get a flame to light up even when the ignitor is ON, which subsequently turns OFF. If you wait a while before restarting the dryer (1/2 to 1 hour) it starts up again OK. I am also uncertain, if the quantity of cloths in the dryer makes a difference.