86300zxNA

Okay so i am a newbie to Z's got my first on earlier this week a great 86 300. Unfortunately its not running so well. After it warms up, at slow speeds and at take off it lacks power and hesitates horribly (at times some worse than others). you can smell the gas from the exhaust and it even sounds like i have small backfires through the exhaust. If i get on the gas once it catches up it takes off and runs great. I ran the engine codes but it seems like i have a later model ECU. Both lights light indicating the mode of the ECU (as far as i can tell) then once you enter the mode 3 it shows Code 13. Now i know the engine coolant temp sensor could cause my problem from what i have read but my question is .... do i trust the codes if the ECU is from a later model 300 or are they switchable? Also is there anything else i should check, before replacing that sensor.
The person i bought the car from said he replaced/rebuilt the heads, plugs wires, cap, rotors, MAF, water pump and timing belt. All these items appear to be good and the running problem seems to be to erratic to be a timing issue. I replaced the oil sending unit cause the oil pressure was erratic which helps that issue but had no affect on the running problem.

Any help you guys can give would be appreciated. i dont have tons of cash just to replace random parts till i fix it and from what i have read on here your average repair shop will be no help.

hoov100

OHM the CHTS and coolant temp sender against the values in the FSM.

86300zxNA

seems i have an 1987 ECU in my 1986 car. someone on a different site says that might be causing my issues? any one know if that is true. all the info i can get says it should be compatible but....

hoov100

Do you actually have an 86, or is that what the title says it is?

86300zxNA

well the title does say 86 but it is a NA with a Spoiler. Has the integrated tail light with the spoiler and the rear tail lights are not in the same style as the 87 and up models. So without checking the VIN and model numbers (which i will do when i can) i would say yeah its an 86.