I have 89 rs 2.8
NEW
Exhaust , MAF sensor , thermostat, temp sensor, plugs, fuel filter,
the car had a 34 code so replaced the maf disconnected the battery waited an hour started the car and the sevice light is still on but only flashes the 12 code nothing else???? and the car is idleing rough smells rich anyone with any ideas on this?

 

sometimes it can take a while for codes to pop up. get out and drive the thing on the highway if you can

how many miles? is the check engine light coming on without storing codes? did you try cleaning the engine with seafoam? I did mine twice in a week, and it made a big difference

 

I haven't sea foamed it, I got this car with the service light on but now it isnt giving a code its just staying on

 

a car that has a light but doesn't store a code could need a fuel filter changed. happened to me

 

Sounds like a valid code to me... But then, why IS the car running at all? Code 12 means the ECM doesn't know the engine is attempting to run (if you want to get technical, the ECM is not receiving reference pulses from the ignition module). It's not a BS code like Chrysler has in which code 55 or whatever means that the battery has either run down or been disconnected/replaced in the last 50 start/stop engine cycles.

Check the ignition circuit wiring, not just the plugs and wires. Well, actually, check them as well to make sure the firing order is correct.

 

Check the plugs at the base of the distributor. I found in my experience that they are sometimes not plugged all the way back in if they were removed at one time. If your plug wires are routed too close to the ignition module wires, move them. The RFI that plug wires generate can play hell with the signals coming from the dizzy to the ECM. Is the car running like crap? If so your ignition module could have puked on you.

 

code 12 just lets you know that the car is in diagnostic mode. everybody should always get a code 12 anytime they jump the pins

 

I think he meant that hes getting this code as one of his actual DTC's. He said his SES light is constantly on.

 

the SES light stays on and the only code being flashed is the 12 code the car idles rough but when you give it a little gas its fine..And it has a new fuel filter

 

How new is the MAF sensor? Is it a parts store reman? If so, pull it off and look at the orange film inside it. If its wavy, its junk.

 

from what i know code 12 is the handshake code telling u that the computer is ok. should always show when u jump the pins. if it is staying on then it sounds like the ecm is fried.