Well, I'll cover everything. Not starting could mean everything is totally dead including dome lights, head lights, dash lights and the starter. Typical causes would be loose, dirty, or corroded battery cables or a loose nut holding the red cable where it bolts to the under-hood fuse box. Also look at the smaller black wire from the battery negative terminal where it bolts to the body to be sure it isn't loose.
If the starter cranks the engine but very slowly, it's usually due to the battery is not fully charged. The place to look would be the alternator. Once the engine is running, use an inexpensive digital voltmeter to measure the battery voltage. I can run you through the steps to do that and to interpret the results.
If you hear one loud clunk from the starter each time you turn the ignition switch to "crank", but it doesn't spin the engine, suspect worn contacts in the starter solenoid. That is a REAL common problem with an inexpensive fix but most people just replace the entire starter motor.
If the engine cranks like normal but it doesn't start and run, there are three circuits to check, the fuel supply, the ignition system / spark plugs, and the trigger circuit that turns them both on. That trigger circuit causes most of the problems. Usually a sensor is defective. Which one depends on which engine you have.
If the engine starts and runs for a couple of seconds, then dies and won't restart, suspect a bad fuel pump. The engine will run for a couple of seconds on the stored fuel pressure from the previous time it was running. Sometimes banging on the bottom of the tank while a helper cranks the engine will get it started. Chrysler pumps almost never quit while they're running. They usually fail to start up.
If the engine only starts and runs when you hold the gas pedal down about 1/4", AND if it tends to die when you coast up to a stop sign, this is a symptom of the battery being recently disconnected or run dead. The Engine Computer has to relearn "minimum throttle" before it will know when it must be in control of idle speed. Until that happens the engine will run too slowly at idle. To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals.
If the engine dies while you're cruising at a steady speed, the most common causes are the crankshaft position sensor on the 3.3L engine, the camshaft position sensor on the 3.0L engine, and the Hall Effect pickup assembly on the 2.5L four cylinder engine.
If none of those symptoms match yours, you're going to have to describe exactly what happens when you turn the ignition switch to "crank". A helpful observation is what happens to the head lights when the problem occurs. Do they stay bright, get dim, or go out completely.
Wednesday, December 1st, 2010 AT 6:44 AM