I'm running em blue and have been doing some logging with my zeitronix wbo2. Even after bumping up the injector duty cycle 8-10% from 2000-3500 rpm above 20% tps, I can't seem to get the afr to get below 14 afr. Once I hit 3600 rpms, regardless of the throttle, the afr drops to about 12. I know the stock ecu is kicking on the variable timing system at this point, and that's fine.

My question is should I continue to add injector pulse width to the lower rpms? I've added about 10% to the MAF signal, but there doesn't seem to be much afr change beyond 10%, as I don't think the stock ecu will add anymore fuel beyond that.

Is there anything I can play with as far as timing is concerned? I've already had the dealer add 2* timing (which, I'd like to add, seemed to have made the car a bit more sluggish ). I'm not a timing guru (yet) but I will be researching the effects of timing adjustments in the next couple of days.

 

Hello,

Because the later model 350Z/G35 relies heavily on 02 feedback the factory computer is probably re-trimming back to its (way to lean) desired a/f ratio. This can be easily re-programmed with an ECU Flash.

With the E-Manage blue it is going to be extremely difficult to tune this area, maybe if you have the map sensor option your could make something work - but not a recommended solution.

Hope this helps,

 

Mike,

When you say "later model", are you referring to the 04.5+ that have oem wbo2 sensors, or just late model computer controlled ecus in general?

I forgot to mention this is on an '03 G35 Coupe with the crappy narrowband O2s. Do you have any suggestions on how to overcome the ecu trimming back fuel, or should I just live with it until such time that I send it in for a reflash?

Maybe more MAF signal in this area would help more than I think it will.

 

MAF signal will help some, but because you are pulling back the entire range at that rpms with the e-manage blue your economy may suffer. This is where the flash really shines.

 

Mike,

The way I'm tuning, I'm hoping to avoid any major economy issues. Right now, I'm doing very little (if anything) to the map below 2k rpms and 20% throttle, which, from my pre-tuning datalogging, is where about 80-90% of my daily driving is.

I was reading the service manual in bed last night (yes, I'm a geek) and it seems that the ecu will continue to make corrections for what it thinks is the proper afr/timing configuration. That's why I think adding more MAF signal will work better than I initially thought it would, rather than relying primarily on injector PW correction. I looks like the ECU will continue to pull PW until it gets to it's preset AFR value.

I now know that an actual reprogram of the ecu is the only true way to reprogram this thing properly, but I'm the kind of person who likes to do things and learn for myself first. Once I firgure it out and get bored with it, then I'll pay to get it done. That's just the way I am. I want to understand what's being done and why before I let somebody else do my work for me.

 

Sounds like a plan. Feel free to give me a call 301.330.8835 opt 4 if you have any quesitons on it - I think I can answer a few more of the questions your going to run into

 

LOL, not only are you a premier tuner, but you're also a clairvoyant.

Thank you for the offer. I may do that soon.