I'm hoping to get some feedback on this dealer diagnosis.

Background:
2000 maxima SE, Auto 14x,xxx miles
When the weather is cold (like it is now), the car starts very easy, a perfect start, but then quickly dies. It restarts again, perfectly immediately, and will die again. You do not need to give the car any gas for it to start. The only way to keep it from dying is to keep you foot on the gas, at least a minute or two. After you get the engine running for about a minute it will no longer die, but runs really really rough at any rpms under about 1500 to 2000. If you drive the car for 20 minutes or so it will run perfectly for the rest of the day, even if you turn it off for hours. Only if it sits overnight does it then have the issue again. There are check engine codes but they are probably related to the issue rather than causing the issue. Like a catalyst efficiency code. There is no loss of power, and no noticeable gas mileage loss.

Dealer diagnosis:
All the fuel injectors are bad. Not one, not two, all of them are bad. 1100 dollar quote. Originally they claimed the injectors were dirty and then thoroughly cleaned them. Now they claim they are all bad. When pressed about how they came about the diagnosis, they relented that they had not checked or verified any of the injectors, they had merely read a TSB and this is what it said they needed to do.

I'm at a loss to figure this out. Please offer any insight you have. Thanks

 

Funny that your Nissan dealer said your injectors are bad based on simply reading a TSB. I went to my dealer today for some common issues with my 03 (flopping hood, 3rd gear issue, and oil consumption). He acted like he didn't know what a TSB was once I told him that I had less than 60k miles and that my car was delivered in July 03. If I were you I would take my car to a private shop and get their synopsis as to what the problem is.

 

Do you have a coolant temperature sensor code? I would bring it to a garage that can read the live data with a scan tool. Leave the car over night with the codes cleared and see what codes come up when they try and start the car in the morning. They can watch the live data and possibly see if something is out of whack. Have them write down the codes in order first to last and you can post them.

 

next time when you feel that your car is loosing power run Seafoam in the tank, and brake booster to clean everything.. My car had a problem with hesitation and the Seafoam, took care of it......... I don't think your injectors are bad... do the Seafoam a few times and you'll see

 

when the car was acting up, were you able to rev above 2k rpm? once at normal operating temp, any hesitation in any rev bands? any possibility that theres condensation in fuel lines? maybe dirty fuel filter? hows your battery voltage? I would first look at the temerature sensor and then make sure the battery holds charge overnight, I've seen wierd stuff happen in car electronics when voltage was below normal, i.e. alt going bad or battery going bad or not efficient for winter, cold weather use.

 

Sounds exactly like the upper intake gasket leaking. It is a known problem, not terribly common, but it happens. I think maybe people simply drive through it until the engine warms up. My dealer sold me the updated gasket that fixed the problem on my friend's car. We fixed it one Saturday last year, no problem since then.

Try this: the next time you start the engine stone cold, as soon as you get the idle stabilized, spray some carb cleaner around the upper to lower intake mating surface. If your idle RPM increases noticeably, you have diagnosed your problem.

It's definitely not all the fuel injectors.