[laynlo15]

So for months we've been fighting what we knew was false knock. We've run from 17 degrees of timing to 22 degrees of timing plus 5 degrees of FF timing and we were still getting false knock. The log numbers were just to perfect so it had to be the blower that was causing the issue since it was making more nosie then normal as it has a coupler rattling a little more than usual. Well over the weekend I was on a pass and at a 1000 ft it starts to misfire and check engine light comes on, shit I was scared I'd broken something again. Got back looked at the log and looked at the misfire and it was on number 5 cylinder. So, thought I'd pull that plug and take a look at it, reached down to pull the plug wire off and it was already hanging there. I'm still using the stock wires with the spring attached that helps keep the wire attached. I'm assuming that plug wire has been loose for some time and just barely hanging on. Put the plug wire back on, car sounded great so waited for my next pass and to come up in a couple hours. The car made a great pass with no misfire or check engine light, looked at the log and no knock on any cylinder, the best log I've seen since we did the build. Why would that one cylinder which didn't always knock cause other cylinders to knock when logging passes. We'd seen knock on every cylinder at one time or another but not every pass, so go figure.

[KingLT1]

Probably because you are still spraying fuel in that cylinder and it's not igniting all of it....and that cylinder is now in a hydraulic situation which is causing the engine to knock. I remember Brett Hydro locking an engine at the track because an ignition coil wasn't plugged in and the connector tab locked. Think of how much pressure is on that rotating assembly with 10-11psi of boost, more fuel for richer AFR, and the fuel is not igniting properly. It's going to act like a diesel engine.

[laynlo15]

Originally Posted by KingLT1

Probably because you are still spraying fuel in that cylinder and it's not igniting all of it....and that cylinder is now in a hydraulic situation which is causing the engine to knock. I remember Brett Hydro locking an engine at the track because an ignition coil wasn't plugged in and the connector tab locked. Think of how much pressure is on that rotating assembly with 10-11psi of boost, more fuel for richer AFR, and the fuel is not igniting properly. It's going to act like a diesel engine.

I guess it was hanging on enough to fire but was a little loose. That's the only time I ever had a misfire or any codes. If that would have been a regular wire with no spring would have popped off a long time ago. All good now and we can turn up the timing again since we are down to 22 degrees with FF included. Wish it was still cool, we might have run the 9.60 I was hoping for with the timing we could have been running.

[laynlo15]

What's the old 38 Special song? Hold on Loosely..