ca20e running like doo doo when its cold.

Hey guys, i got an 85 200sx with a ca20e in it.  The Bottom end has about 100k on it, and the head is freshly rebuilt.  I just did a tune up on her and now that its cooled down in my city shes started to run like crap!  I have to let her warm up to at least 120 degrees or she wont idle right, seems to bog a lot and when shes below 120 she seems to be running REALLY rich, to the point shes blowing smoke under heavier throttle.  Can i get some help pointing me in the right direction?

Two ideas: Check your codes, and it could be your IACV/air regulator, which affects cold idle warm up.

NismoJames on 06:11:55 AM / 04-Dec-12the head is freshly rebuilt.

NismoJames on 06:11:55 AM / 04-Dec-12just did a tune up on her

New plugs(all 8 >.<), oil change/oil filer/air filter/fuel injector cleaner

Where can i get my engine codes at?

Im not sure about the EGR or the IACV, i will check those asap

For the motor, the guy i bought it from had the 1.8 in the car and it died, he had another 200sx with the 2.0 in it, but the body of the car was all messed up.  So he did the swap, but when he did, he rebuilt the head and changed all the gaskets.  From my understanding it was running before, but it was something he wanted to do i guess.

He mentioned something about the fuel injectors sticking because he never replaced them, could this be the issue, or does it sound like BS?

So was it running ok before the tune up & after the tune? You mention the change with the cooler weather, just wanted to know that it was running well after your work.
Pull your codes off your ecu, need to consult service manual for specifics. If you don't have a FSM yet, check out ebay, they are readily available usually well under $50.00.

Nobody suggested the engine coolant temp sensor?
If the ECU doesn't know the correct coolant temp, it's not going to apply the correct fueling to run it right.

Otherwise vacuum leaks could do it too.

It was running ok before the tune up, but that was when it was still warm.  She sat for a month or two then I gave her the tune up.

As for the coolant sensor, the guy I bought it from has hooked up an aftermarket temp gauge to her because he only had the turbo gauges and they didn't work with the ca20....hmmm I'll see how it's weird up.

Where's the eco located in this car?

Both are located on the intake, just under the throttle body, near the radiator hose.
It's the one with the wider connector, the other one is for the temp gauge (the ECU doesn't care about that one).

I guess a good detail to add would be that the car sounds like and feels like it's missing when it's cold and that goes away once it reaches normal operating temp.

NismoJames on 10:59:16 PM / 04-Dec-12Where's the eco located in this car?

It ran bad when the wether changed and got cold.  I did a tune and it ran slightly better.  Once the car warms up after a few mins it runs a lot better but still seems rich.
Post Merge

Once you are at normal operatng temp, does it run normal or still same problem?

It feels like its bogging down and missfiring now.  When cold it does this, and it wont idle, i have to give it gas till it warms up.  Once warmed up it will idle on its own, BUT it still boggs down and feels like its missfiring, when i give her a lot of gas, she'll even throw some black smoke that smells like gas....Could this be a dead give away to something?

Like Rednucleus said, sounds like could be the IAC. This device adjustes the idle mixture to help warm up the engine. It has an internal electric heater that heats a bimetallic strip, this in turn rotates as it heats and adjusts a rotary valve that adjusts idle airflow. This device is in the intake, not real sure on the CA20 as I have a CA18ET. It will get gummed up and stick over time, so look it up in the service manual and pull it off and clean. The temp sensor is also another thing as has been pointed out. I used to get this same event years back, it was undrivable until the engine warms up a bit. Yes, sounds like it runs on 2-3 cylinders and blows smoke. I cleaned EVERYTHING when I did my rebuild, no further issues. If you have a stuck injector that could certainly make life with your S-12 bad. Maybe having injector cleaning would be helpful also.
Good luck, keep after it.

Here's the part Cajun & I are talking about. When mine went bad it ran really rough and I needed to replace it. 

ca engines dont like the cold my car runs like crap when its really cold

When I had a CA, it ran just fine all the way down to -20F, didn't have any AIV, EGR, or even the cold start air regulator...

My CA would only idle and wouldn't accelerate when it was cold out. Would spit and sputter. Once warmed up, it was A-OK.

So I swapped in a KA. That is my advice.

Jay on 07:24:14 PM / 08-Dec-12So I swapped in a KA. That is my advice.

d_k_jose_s12 on 11:39:18 AM / 08-Dec-12ca engines dont like the cold my car runs like crap when its really cold