check engine light on 1995 240sx

[KrugNCSU]

How can i go about finding out whats wrong with my car?
I don't know whats causing my check engine light to come on, the car runs fine but i have no idea how to check whats wrong with it.
I was hoping someone would know how to do a self diagnostic on the ecu instead of taking it to a mechanic.

[Replicant_S14]

Dig through the FAQs at www.240sx.org

Some of that stuff is dated but I think I remember seeing ECU codes there.

[Nolaws4evr]

jump in your car and drive up to autozone real fast, then have the dude come out and plug up their diagnostic computer to your ecu and pull the codes. Its free, its fast, its easy, and did I mention free?? The ecu is on the pass side in case he cant find it.

Josh

[AJ]

do they still have to pull out the ecu.. caus if they do,, just do it yourself.. turn the screw wait 2 sec, turn it back... look at the led on the dash.. ur check engine light will b blinking,, record number of slow blinks and fast blinks... then when ur satisfied (they will repeat), turn the screw again,, wait 2,, then turn it back to its origianl possition... and its cleared.. and won't come on if u fixed the prob... and will if u didn't :-D..

[AJ]

thats what i do on my s14 anyways... and,, do all this with the key in the on position, but don't start the engine.. starting the engine and turning that key puts u in all sorts of weird modes and stuff,, its scary, dont' mess with it.. i did (caus i thought i was clearing it and wasn't).. and had my engine light blinking when i'd step on the gas,, and off when i wasn't on throttle.. (lean/rich condition people said).. it was weird.. sorry if this makes no sense.. i'm tired.. :-D hope i helped.