For a year now the blazer has been difficult to start with at least 3-4 seconds of cranking. It is usually followed with what I believe is the ignition cutting out for a fraction of a second as you accelerate and maintain speed. The condition usually settles out after a few minutes. The engine was completely replaced in 2009 by pep boys after they "forgot" to put oil in it so basically all the wiring in the engine compartment could be suspect.


The other indication I have is every time the ignition cuts out causing the car to buck, the battery light will flicker on for a fraction of a second. In some cases of a series of these events I will catch the ABS light flicker on for a fraction of a second. I believe these are occurring because of the lamp test when the ignition is first turned on.


All these signs make me wonder if it is all just caused by the ignition switch, but I am just not sure where to begin. I don't just want to start throwing money at it hoping I find the culprit when it could be just a loose or dirty ground connection.


I already kind of wonder about the ignition switch however because it sounds to me like when I turn on the ignition switch sometimes I hear no noise, but when I turn off the ignition switch I hear the 2 second prime of the fuel pump. I was under the impression that it should be inversed where it primes when you turn the ignition on not off.



Any ideas?




EDIT: Forgot to mention sometimes a P0339 "Faulty crankshaft position sensor" will pop up after an event, but it does say on the code that it can be caused by low voltage which I believe is my case.

 

P0339 indicates an intermittent problem in the feed circuit to the crankshaft position sensor. The ECM 1 fuse in the underhood fuse panel feeds the ignition control module, ignition coil, and crankshaft position sensor, through a pink wire. If that circuit loses voltage intermittently, only the crankshaft position sensor will set the code, NOT the ignition. As intermittent as you say that it's happening, you might want to rig up a temporary pilot light to the pink wire at any one of those components. Any auto parts store will have a socket for a #194 bulb. It has two pigtail wires attached to it. Lay the socket in the console, etc, and ground one of the wires. Run the other wire to the pink wire, close to the crank sensor would be best. If the light blinks when it acts up, you know you're on the right track.