RED MX5

Is there any way to fool the ECU (to avoid the CEL warning) after removing the AIR pump?

krazik

yes.

but I don't know how. I just live w/ the check engine light.

moving to under the hood.

RED MX5

[QUOTE]Originally posted by krazik
yes.

but I don't know how.

redsound

[QUOTE]Originally posted by RED MX5

RED MX5

[QUOTE]Originally posted by redsound

Slows2k

Mugen, or any JDM ECU is the way to remove all the OBDII systems. The Air pump monitors that the PCM runs are to complex to build a "simulator" for.
Stock JDM ECU's do have a top speed limiter

RED MX5

[QUOTE]Originally posted by Slows2k
Mugen, or any JDM ECU is the way to remove all the OBDII systems.

Slows2k

I think it's 125mph


The Mugen ECU has advanced timing maps over stock, and minimal timing retard from the knock sensor. I don't believe it requires much tuning, Other than keeping high ouctane fuel in the car. I think there has been multiple posts on the Mugen ECU, what it all does differently from the stocker.

RED MX5

Thanks for the info. I've taken a look at the Mugen ECU (thanks to your lead), and I'm a little concerned about using it here where the temps and humidity tend to get very high. The slower knock sensor response worries me too. I think I'm going to try pulling the back-up fuse and letting the stock ECU reprogram itself each time I start the car. I drive very conservatively until everything is thoroughly warmed up, and the cost of pulling the fuse is hard to argue with. It remains to be seen whether or not I'll be able to live with the rough running for the first few minutes after each startup.

Thanks to all, for all the good information. This forum is an amazing resource!

RED MX5

Hyper-X

The Mugen ECU is a great way to improve on the OEM ECU as no additional tuning is required. As it was already mentioned, you must make sure to use premium fuel (92 oct or better), but you should already be doing this on a normal S2000.

The Mugen ECU runs the AF ratio ideally, and doesn't require any tuning using a VAFC, as it would be overkill. It also runs a lot more timing and doesn't retard as much as any OEM ECU so it's great for performance. My only reservation is the price and the fact that it removes all of the OBDII equipment and the immobilizer won't work, which is why it's a race-only piece. If you do a search, you'll find an excellent post by Ultimate Lurker that explains much of this in detail.

I chose a different route using a newer MY02/MY03 ECU on my MY01, and tuned with a VAFC2 to achieve ideal AF ratios. The drawback is that the Mugen will still run more timing as the VAFC does nothing for that, however I still have all of the OBDII sensors in place, along with the immobilizer and the added option of altering the VTEC transition points going up and down the powerband, and I have multiple setups for normal driving (which keeps everything stock) and a race setting (which engages VTEC a bit earlier, and keeps it in VTEC longer before going back to the normal cams during decel, which helps in auto-x).