I have a goodman gmpn0804 furnace that will not ignite (and the igniter is good) . The inducer motor runs, gas valve comes on, no ignition, gas valve shuts down . If I manually reset the furnace (turning the power off then back on) ? The furnace will lite, cycle several times it may run perfectly for several days then the problem starts over again. Any thoughts?

What is the status LED doing when the unit malfunctions? On the surface, the hot surface ignitor is the most likely culprit, followed by the circuit board (faulty ignitor relay). HOWEVER, I have encountered this scenario in the field on a few occasions: The pressure switch was passing enough voltage to trick the circuit board diagnostics, but would not support the circuit current when other devices were introduced to the operating sequence. This is a tricky one when the unit does not function at all; yours may be even tougher to nail down as it is inconsistent.

I had the same problem ams replaced the ID draft blower preasure switch. Worked great for a couple of weeks, then it stop and a plastic smell resulted. I noticed a cut in the preasure valve tub witch may have burned the ID draft blower. Looking for help on that one as we speak.

I also had the same problem, my furnace would not ignite, the furnace would shut down after 3 tries and the PCBoard would blink once. I checked the safety switches with an ohm meter to make sure they were in the closed position (0 ohms) and they were all OK. I decided to change the Ignitor even though the one in the furnace was working, after replacing the ignitor the furnace turned on the first try and has been working ever since, apparently the ignitor was faulty it was not getting hot enough to light the gas, you can get the ignitor from Ebay for around $18 here!

http://www.ebay.com/itm/261352276661?ssPageName=STRK:MEWNX:IT&_trksid=p398 4.m1497.l2649