Up until yesterday I would have sworn this only happened when the car was cold, but I'm now having warm hard starts too.

I searched and read up on MANY different things, but my issue is now not constrained to cold starts. My car started right up yesterday morning and this morning. Then this morning, I stopped to get coffee, came back out and car would not start on first try - second try hurt to listen. After holding the key to start it for 2-5 seconds, it did turn over (on that second try), but this is now scaring me. I feel like I could get stranded at any moment.

Since this is now happening on warm starts and not just cold starts, is this likely a fuel delivery problem? I'm really thinking it's the fuel pump but I'm no expert. The only thing I can think of that I haven't replaced is my fuel filter. However, if I'm not mistaken I had the fuel pump go on me in my senior year of college (2000) and it was replaced under either warranty or recall. Would/could the fuel filter be the source of this problem? As with everyone else's stories of hard starts, once it's started the car runs very well, but that start really worries me.

Car has 83,xxx miles on it ... wondering what the experts think.

 

Drive to AutoZone to have your battery, starter, and alternator tested for free. That should be a start to fixing your problem Are your battery terminals clean?

 

I will certainly do that this weekend. That's a good suggestion and a free one at that.

The other thing I notice is that when starting up my oil light flashes twice or three times real quick and then goes out. Not sure if this means anything but I thought it was worth mentioning.

Let me also mention that most warm startups are uneventful ... the one this morning really caught me off guard and obviously prompted this posting.

EDIT: yes, my terminals are clean. They're new terminals on a 1-2 year old Optima battery and I had my alternator replaced under recall a little over a year ago I think (could be less than a year).

 

Would think a bad fuel filter would show signs while the engine is running as well. Dunno.. anyhow i'll bump your clutch post so you can give us an update eh?

 

According to Haynes manual for hard cold starts:
- battery
- fuel system problem
- bad coolant temp sensor and/or intake air temp sensor
- injectors leaking
- bad MAF sensor

For hard hot starts:
- air filter clogged
- fuel not reaching fuel injection system
- corroded battery terminals, especially ground
- bad coolant temp sensor and/or intake air temp sensor

Get a Haynes manual and check the sensors with a multimeter and see which ones need replacing. Have you done your tuneup?

 

Have the fuel pressure checked.

 

Check both crank position sensors for build up of fine metalic dust. One is located under the lower pully and the other is located on the transmission bell housing, twards the front of the car. They are magnetic sensors and tend to collect fine metalic dust which can causes a weak signal to the ECU thus giving you a hard start. Nissan is actually having sort of a recall on the crank sensors because of this. They are also known to fail without setting any error codes in your ECU or turning on the check engine light. If crank sensor (POS) fails, your car will not start. If the signal is weak, you get hard starts.

 

definitely have this checked.