I'm having an issue with hard starting when the engine is cold and the temps are below 45*. It will fire and then stall. Unless I open the throttle some it won't fire. If the engine is warm or the temps are warm no problem starting. It's not throwing any codes. This is the second year it's done this. Any ideas where to start. Plugs were replaced last summer.

try cleaning your throttle body. that should fix it. and be sure to read the FAQS and STICKIES!

Yeah I know what you are talking about I am experiencing the same problem right now with my Maxima. I took it to a shop and they said the diagnostic was showing my crank sensor was bad. I had them replace it and all it did was help my steering wheel feel more tight, but didnt stop the cold start. My dad is going to clean my throttle body this weekend, because many people on here said that could be the problem. If that doesnt work then I'll try replacing my coolant temp sensor, if that fails then I really dont know what to do then!

OK, I'll give it a shot.

These steps in order should solve your cold start problem.

1) Clean the throttle body.

If you still get hard starts...

2) Check the engine coolant temp sensor, make sure it's resistance is within spec at the specified temperature. If it's not, replace it. The Haynes manual has the table of resistance ~vs~ temperature.

If you still get hard starts...

3) Check the adjustment and operation of the cold idle circuit. There is a plunger and linkage that opens the throttle plate slightly when the engine is cold. If that's not working or adjusted properly it can cause hard cold starts. Again, the Haynes manual as a good write up on that as well.

Also make sure you have no codes such as a cam or crank sensor fault stored in the ECU.

Where in the haynes manual does it talk about the "cold idle circuit"?

check ur fuel pressure regulator if the car's exhaust smells like gas when ur car stalls

Section / Page 6-18 There's a nice picture of the alignment of the cam and follower pin and detailed instructions on checking and adjustment of the system.

EDIT: It's actually called the Fast Idle Cam in the Haynes manual.

As soon as i steped out of my car i smelled gas! went to the rear and it was like someone spilled fuel near my exhaust (because of the smell) i might be exaggerating a bit, but it smelled. anyway can you describe what the fuel pressure regulater does?

I did the cleaning of the throttle body today. I thought it would be nasty looking but it wasn't too bad. Cleaned up nice and cleaned my K&N while I was at it. I won't know if it helped until the engine is cold. It did seem to run slightly better. I noticed the "cold idle circuit" and tried to move it but it didn't move freely. I don't know if its supposed to or not. I'll look at that next if I still have a starting issue.
The brackets that hold on the radiatior and the hood open switch were getting corroded so I cleaned them up and painted them. Are those common to crap out?

It does execally as the name suggests... regulates fuel pressure... i might be dumping too much gas into the intake manifold upon start up thus causing the car to stall and be hard to start... happened to my old car

is there any way to be absolutely sure that this is my problem and not just my camshaft position sensor (as the ECU says) thats causing my occasionaly hard start?

My problem was solved! No problem stalling on a cold start. Thanks.