Sorry if this is newb like... Haven't worked with obd0 much.


Car is 91 si with stock PM6 ecu.

I get a random CEL, comes on about once a day. I am running a bit rich and sometimes the fuel loads up around 3500rpm and hesitates, but if you floor it it'll clear up.


I looked at the light on the ecu with the car running and also with it off and ignition on.

All it does is flash one short blink, and then a one second pause. over and over. It never does any 3 sec breaks between codes.

It is just blinking at the same rate over and over like an alarm light or something.

Any ideas? is this just code 1 or something?

 

Sounds like an O2 sensor code (code 1)

 

Isn't it supposed to blink once all the time to indicate all systems are a go?

 

OBD0- 1 blink is o2 sensor, but that does not mean the sensor is bad. It means that it is working and is sensing that you are running rich like you said it is. Fix that first and your CEL should go away (after you reset the ECU).

 

I understand that 1 blink is o2 sensor.

What I don't understand is why my ecu doesn't pause between blinks like it should.

According to helms, 1 second pause is the pause between numbers, 3 second pause is the pause between different codes.

If it was only code 1 wouldn't it blink, wait three seconds, and then blink again?

Mine is blinking consistently every second. Maybe it is only the o2 code. Thats why I'm asking.

 

I'd bet my money on the O2 code as well.