Need engine misfiring advice Options

[oakdalecurtis]

Here’s a question for the braintrust.
I have a 1974 stock FI original motor, 130,000 miles. It has a Crane Fireball ignition and Novolny plug wires. It has always run flawlessly from startup. Lately, upon cold start, it has been badly and randomly “missing” for the first 2 minutes, especially on acceleration. It is not a constant steady miss on one cylinder. I can’t say that is isn’t one cyclinder doing the missfiring, but the miss is random, 2 seconds, 4 seconds, 3 seconds apart. Then it runs flawlessly after the first 2 minutes.. The AAR valve works fine. The MAPS board has been replaced with a new one a while back. I have checked that all the plug and coil wires are tight. I thought maybe some long term water concensation in the gas tank might settle and cause an issue. I added a fuel additive to prevent that, made no difference.
What do these clues indicate on where to start looking for the this inital start random misfiriing?

[oakdalecurtis]

Thank you all for your suggestions. I found the problem. I’m embarrassed to admit this, but I will so as to maybe help someone else sometime. I opened the air cleaner and the K&N filter was really dirty and plugged up. After cleaning, the car runs perfectly! Here’s what was happening. When the car and the K&N filter was cold, the thickened K&N filter oil and gunk restricted the air flow so much that upon acceleration, the engine could not get enough air to fire consistently. As soon as the filter oil warmed and thinned slightly, it allowed enough air to pass through to fire the cylinders properly. I feel like an idiot for not keeping the K&N filter cleaner, but maybe my experience will help someone else solve the same problem….