My car intermittenly starts sometimes. Cold or hot doesnt matter. Sometimes it would work for a week and then just not want to, and then all of a sudden it would start. Latelty it has gotten worse, and Im noticing a lack in performance.
When I turn key to "on" position the ses light stays on. I tried pulling the codes but all it does it flash code 12 over and over again. (Even after the 3 times its supposed to). I disconnected the battery for some time reconnected it. I have also unplugged the ECM and reseated the chip inside to make sure its seated properly. After that it still wouldnt start. Then I went under the hood, and reconnected all the spark wires to make suer they were secure. In unplugged the tps and iac plugs and reseated them also. Pretty much I checked all the connections. Went inside the car and it started, but I still feel the lack of performance. What the heck?

Today after work Im going to replace the ignition module under the cap. Good idea?....or should I look elsewhere? Thanks

 

Code 12 is normal, and it's normal for the SES light to be on with the key forward and engine not running. It just means that the ECM doesn't see ignition pulses from the distributor, because the engine isn't running. It's also normal for it to flash the code over and over. When you jumper the ALDL connector, it flashes each code 3 times, then starts over, repeating forever. So, it flashes code 12 three times, has no more codes (should be a slightly longer pause), then starts over again, with code 12.

What year/engine is this on?

 

cars an 87 the engine is a 90 tpi 350. Either way its been intermittenly running/idling like crap and sometimes would flicker the engine lightwhen Im at a stop. Last night I replaced the ignition module, cap, rotor, and coil. Currently its running like a dream. Better than it ever has. Im beginning to think that when I swapped out my 305 for this 350 I needed to change the ecm also. Although I did order a 350 prom from tpiparts.net, but it did not make a difference in how she runs (it actually runs a lot better with the 305 prom.) think its time for a custom chip.