Ok guys, I've got a Rev built Basic MS3 I have been extremely happy with. The only thing that's driving me crazy is a warm idle misfie I can't get rid of. Car runs great otherwise but the idle misfire is annoying as hell.

I've tried richer/leaner, faster/slower, different dwell settings, new plugs, different throttle body, different ignition timing, sequential/batch fuel......................don't know what to try next.

The rest of the rev range, car runs great with no issues. With the original MS1PnP never had an issue with this. This has got to be something simple I'm overlooking.

I remember Brain complaining about this at one point but didn't see a solution when I searched. Any ideas/help would be greatly appreciated.

Attached is an idle log and my current tune

 

Needs more info:
- Is the MS the only thing you changed when this started happening?
- Ignition system?
- plugs?
- injectors?

 

Assuming his sig is accurate: 460cc inj, COPS

 

Nothing other than the ecu was changed initially. The miss only starts to occur after the engine comes up to around 160-170*. The miss didn't start until I installed the MS3. It doesn't effect the functionality, just sound like crap.

 

My issue was my TB tensioner wasn't tensioned, so the timing was getting all out of whack.

 

Yeah, I'm thinking its gotta be something mechanical but I'm lost. I'm sure it's something stupidly simple. I just hope if I can make it go away, I'll know why

 

How much dwell were you running on the MS1?

 

4.5 cranking
2.8 running
.5ms minimum discharge period

 

seems pretty low for stock coils, IIRC you should be at 5.0 running.

 

Running Toyota COPS in wasted spark.

 

then that's high for them; should be 1.9-2.1ms.