New ECU causing misfire #4 Cylinder

[SilverDreamZ]

Hey guys. New to Nico!

After much research and calling around, I'm still not getting a clear answer to what my problem could be. The other day I installed the new ECU upgrade from Z1 for an NA. I found that for some reason it is causing my #4 cylinder to misfire. With the old (factory) ECU everything works fine, all cylinders fire. I've of course checked on many of the basics (cleaning connections, wiggling wires, switching coil packs, etc.) but it seems to only happen with the new upgraded ECU. The diagnostic test is showing code 55 (no malfunction). Any ideas to what my problem could be? I even put the old ECU back in to be sure I didn't fry anything but it worked fine. Put the new one back in and it is a consistent misfire, cold or hot start. Any ideas?!?

[nissanfreak12]

Call Z1 and let them know what is going on. Its posssibly an issue with a driver in the ECU or a bad tune. I had one from concept Z, they fixed it, mine ended up being something as easily from a different year chassis. At least that is what they told me.

[SilverDreamZ]

Thanks nissanfreak12. I called SZ, CZP, Dan at Premier Z, and from what one of them told me Ash as well, they say the same thing you're saying here. One of the drivers is failing to send to that cylinder. I've also heard things like PTU, TPS, bad connectors, etc., but I can't see how my old ECU would run perfectly fine then all the sudden a more aggressive tune show a problem so major. I'm leaning towards the bad driver obviously now. Ps sorry for the delay just been at this thing hard with not much time for anything else! Wanna drive my Z like normal again!

[nissanfreak12]

I know the feeling, I would just send it in to CZP, I know he can fix the driver. But honestly, it would be cheaper to send your factory ECU, which you know works in to get socketed and chipped on the tune you have.