https://honda-tech.com/zerothread?id=944477

When my car warms up (HPDE warm, not street warm), it starts running really rich and misfires. Details in link...

 

maybe because hot air = less dense, which means less air going.

 

Yup, I figured as much, but I also figured the ECU would take care of that with the IAT sensor.

Not sure there's a workaround for this with E-Manage, if it is really temperature related. I've still got some room to lean it out at normal temps, I suppose, but that's not exactly ideal.

Does the stock ECU richen the mixture when it sees hot intake air? Seems like a 'fair' idea at best, but possibly trying to keep engine temps down.

-Chris

 

Bah, just took the plugs out, was expecting them to be fouled, but they're not. take a look:

 

Those plugs look like they are on the lean side to me, but what do I know...

 

if he suspects hes only running richer while running hot, he'd probably have to run hot, then WOT and shut off motor right after...

 

Yeah, these plugs have 2.5 hours freeway, then 1 hour on the track, then 1 hour freeway coming home. So some of the soot probably burned off. If I trust my WBO2 gauge then I was very rich when warm.

I'm thinking WG placement (closer to the 1/2 cylinder than the 3/4 contributed to 1/2 getting more flow and getting a better intake charge, and probably running leaner/hotter than 3/4. Flow-testing the injectors isn't a bad idea either. (EDIT: Wait, that's backwards, #1's ceramic is the most tan.. that means it was... umm... cooler?)

Either way, more tuning is in order

 

FYI,

1998 B18C5, 310 CC injectors, Greddy kit, Greddy intercooler. stock (50 psi?) fuel pressure. 210 HP at 5-5.8 PSI, running around 11.5:1 up to 8000 RPM where it goes off-scale rich.

"Boost Limiter" Voltage clamp is at 2.9V... hmm, I'm getting a Code 13 periodically, maybe this should be 2.75?