Cylinders 3 and 4 are dead, why? Options

[Skid]

I just brought home a 73 1.7. This is the first 914 that I have actually owned, but not the first one that I have driven. My dad has always had a few 914's around and I finally decided it was time to get one of my own. When I first picked up the car, it ran pretty good and smooth. The original fuel injection has been removed and replaced with some duel single barrel weber carburetors and it has a 009 distributor. Like I said, the car ran pretty good when I first got it about 2 weeks ago. For the past 2 weeks I haven't driven the car more than just around the block, and suddenly, out of the blue, I went to go move the car and it is running bad. It has a definite misfire and, when I pull the plug wires off the distributor cap, 3 and 4 seem not to be firing. I have checked compression in those two cylinders and they are fine. I am getting fuel (I can see that the carb is squirting gas), and I have also tested to see that I was getting spark on those two cylinders. If I have spark, fuel, and compression, what am I missing? How could it just change overnight? I am pretty stumped here, my dad, who has worked on these things for over 20 years is also pretty stumped. Any ideas or help would be very appreciated.

(IMG:http://www.914world.com/bbs2/uploads_offsite/lh5.ggpht.com-3538-1273364830.1.JPG)

(IMG:http://www.914world.com/bbs2/uploads_offsite/lh4.ggpht.com-3538-1273364831.2.JPG)

And the mess of an engine bay..... (IMG:style_emoticons/default/barf.gif)
(IMG:http://www.914world.com/bbs2/uploads_offsite/lh6.ggpht.com-3538-1273364831.3.JPG)

Thanks,
Chase Birks

[JamesM]

Hurry up and get that thing running, you have a PCA autocross to get to this sunday! We need more 914s there.

Let me know if you need a hand... or parts. My house is starting to look like a 914 wrecking yard. (IMG:style_emoticons/default/smile.gif)

[Skid]

Ok! I figured it out! Boy do I feel stupid. I worked on the car for hours on saturday. I changed plug wires, plugs, rebuilt the carb, adjusted the timing, and a few other things, and nothing helped one bit. I was playing with the timing when the car backfired and my dad noticed that flame came out from the manifold on the dead side. He reached down and stuck his finger over the hole, which was just out of view, and just like that, the car sprang back to life and ran just like before. I guess some little plug that had been there before must have fallen out and caused a vacuum leak. So for those of you who guessed vacuum leak, you win the prize! Thanks for your help and info. I am sure I will be needing lots more of it as I get this little guy back on the road. Next step, emission and inspection, wish me luck.