QuestionHi..... my mechanic is currently working on my car and is stumped. For 2 months now I have had intermittent problems starting my car (2004 Santa Fe 2.7 L, V6)..... it always turns over, but only after "Cranking" the key in the ignition for 10-20 seconds. It seems to be worse 1 of 2 times: after sitting for long periods of time and when it is sunny/hot outside. If it's really hot (say 85+) I can have trouble starting it just 15 minutes after it ran. The battery is fine, the altenator and starter are fine, as well as transmission. My mechanic just said that the pressure on the fuel pump seems to be ok also. I've also noticed that if I give it a little gas right after cranking it that it seems to turn over quicker. Any ideas? My mechanic is totally stumped.
AnswerHi, Nikki. I cannot tell you what the problem is, but I have some ideas. First, though, I'll start with some questions. The answers to these questions will help point us toward the actual source of the problem.
1. A common occurrence causing this problem is fuel pressure bleeding off through a faulty fuel pressure regulator when the engine is off. You say the fuel pressure seems okay. Does this mean it's okay when the engine is running or that the system maintains pressure when the engine is off? How was this check made?
2. Has your check engine lamp been coming on?
3. Did anyone check for diagnostic trouble codes in the engine control module? If so, what, if any, codes were present?
4. When the problem occurs, does the check engine lamp illuminate at least briefly when the ignition is turned on an the engine cranked?
5. When the problem occurs, is there spark at the spark plugs?
If you know that you have spark and proper fuel pressure, then I'd suspect a problem with one of the sensors (most likely the coolant temperature sensor) reporting data to the engine control module.
If you have no spark, I'd suspect the crankshaft position sensor.
