So whatever this is, started almost a month ago, at idle there’s just a random intermittent miss almost all of the time.. I thought it was fuel related at first, so I swapped carburetors, which seemed like it helped a little bit but still did it. I made probably 6-7 runs in a row and the last two it was really acting up bad. It ran fine at full throttle, but kept giving me problems at idle.. does anyone have suggestions what to check ignition related or something else?

Is the car still running the number it usually runs. As dumb as this may sound I have seen a leaking header gasket sound an awful lot like a miss at idle. And you wont notice it at wide open throttle. Most ignition issues of seen become more magnified with RPM and load.

It ran the number 7-8 times in a row yesterday at WOT, grid graph shows no spikes, it’s real smooth except one little dip one run in high gear and once after finish line

You have Grid so use it to look at the ignition when you experience this problem.

In Grid Data Acquisition / Start Recording tabs program the Engine RPM Above to 400 rpm. I’ll assume the AND is Launch Input and STATE is ON. In Stop Recording tab program the Engine RPM Below to 100 and the Maximum Recording time to 180 ( 3 minutes).

In CHANNELS tab ENABLE the Ignition IN and Ignition OUT channels.

Here’s how this works. When you start to experience this problem cycle the Trans Brake button. This will start the Grid DA recording. After you’ve experienced the problem several times turn ignition off and retrieve the DA.

Open the DA and select the Engine RPM , Ignition IN and Ignition OUT channels. Expand the DA so that you can see the individual Ignition IN / OUT pulses. Look for your miss problem. This will be a missing Input and Output pulse.

Okay, I’ll give that a try Mark! I just don’t understand how it’s completely fine full throttle, going down the track.. but at idle it’s doing it...