ZC emission way off

[89crx-zc]

Greetings,

I put a ZC in my 89 crx si. It runs great and gets over 30mpg in town with snow tires (Colorado). Unfortunately is failed the emissions test really badly. The HC is always high, so I'll buy a new cat. The original motor ran so much smoke through it that I can believe it's shot. At idle the CO is .3, but jumps to 6.2 at 2500 rpm. When I re-tested, I did it while it was cold. The CO at idle jumped to 3.2, and the 2500 rpm dropped to 2.5. The only thing I can think of that is temperature related is the intake air temperature sensor.

It's running the si ecu, has a new O2 sensor, distributor cap, etc. We kept the si throttle body also. I've checked the fuel injector resistance and it's OK. The fuel rails and injectors are what came with the motor. The plugs are new platinums, but are getting black from the rich fuel mix.

Any ideas on why the mix is so rich and should the IAT sensor make that much difference?

 

[Tom]

change the si ecu outta there it needs a 89 integra for two reasons, one is for the correct feul curve and two is for higher rpm's from factory.

 

[89crx-zc]

Thanks for the reply. I had thought about doing that since a number of the sensor components were probably closer to the Integra motor than the crx.

Hopefully I can get some parts in the next couple of days and try the test again.

 

[Ninefivejiggaja]

heres a pretty general noob question but its been buggin me, is the ZC one engine or is there many types of ZC and what is the displacement on it.

 

[civic1582]

ZC is the D16A8 1.6L DOHC non-vtec engine

 

[Tom]

ZC is the D16A8 1.6L DOHC non-vtec engine

wrong the zc is the zc 1.6 sohc vtec stamped zc, or the dohc motor which is stamped ZC16 non-vtec.