The most common cause of the fridge not lighting is stale air left in the
combustion chamber--usually air that has propane still in it. The little pump
on the fridge is insufficient to really move this air away so here is how I
start my fridge:

I keep  3 feet length of tubing under the fridge and when it won't start I
attach this tubing to the drain plug at the lower left corner of the fridge
door. Then, I suck the air down and out of that drain plug with my mouth
until the air no longer tastes of propane or smoke.

70 percent of the time the fridge then lights normally. 

30 percent of the time, I have to keep drawing air through this tube gently
for one minuite after the fridge has lit or the fire will go out. 

100 percent of the time, after conducting this operation, I brush my teeth
and wash out my mouth. Yuk!

Derek Drew 90 syncro westy

P.S. I think the factory vent covers actually decompose automatically in the
presence of sunlight and then crack and fall apart. I bought some from Delta
Six. Delta six of north hollywood California. They told me at Delta Six that
they will sell at a huge discount in quantiy. Perhaps we should assemble a
group of us to buy 100 of these covers at the quantity price (along with some
skylights).