OK, so car runs fine the 9 months that I've owned it. All of a sudden, it won't start one morning. It turns over just fine and fires. It runs for a split second and then dies. If I give it gas at just the right moment while turning it over, it will rev. It revs roughly. I slowly let off of the gas and when it gets to idle speed, it dies. From what I'm reading, I'm thinking EGR valve, but the codes it's giving me throw me off. I get the codes via the on, off, on, off, on method.

Code 12-Problem with the battery connection. Direct battery input to controller disconnected within the last 50 ignition key-on cycles

Code 77-Speed Control Power relay circuit is open or shorted.

Neither of these codes seem like they would affect the vehicle's idle, so if anyone can help with my problem, please do. This is the only vehicle that I have. I have 40 miles one way to work and have a wife and little girl depending on my paycheck, which I may not get any more of if I don't show up to work soon!!!

 

Code 12 merely means that some time in the recent past (within 50 starts), the battery was disconnected. If that did not occur, check battery and wiring for corrosion or looseness.

I can't believe that code 77 has anything to do with your problem, unless there's a bad connection or ground that is affecting everything.

Check for fuel pressure, spark.

If these don't help, start looking for alternate transportation.

 

I unplug the MAP sensor and the car will start and drive, but not like it should. It still idles a little rough and severely misses out at higher rpm, but driving around town it runs fine. I'm assuming either the MAP sensor is bad, or it was sensing something that made it want to shut down the car. What things would cause the MAP sensor to shut off the car.

 

The MAP sensor reads the pressure (vacuum) in the intake manifold and using that information, the computer adjusts the spark timing and fuel delivery. If the reading is way out of line, a trouble code 13 or 14 should be set. If the reading is far enough out of line (but still within a reasonable range) it will deceive the computer into screwing up the engine control, apparently sufficiently so the engine won't run in your car.

You probably want to replace that sensor, but there may be other things going on as well. You may want to give it a tune-up with new plugs and wires, maybe that EGR valve you are suspecting, PCV, etc.

 

I went to Autozone today to buy the Crankshaft Positioning Sensor. I took my MAP sensor in to have it tested while I was there. It ended up being bad. I went ahead and bought the MAP sensor only and hoped that it would solve the problem. It works!!! Thanks for all of your guys' help. Seems as though multiple sensors can cause the same symptoms when they go bad. Process of elimination is what worked for me. I just happened to get lucky that the first thing I tried worked. Hopefully it'll be a while before you hear from me again!!!