2004 quest won't start warm, unless I press gas pedal

[CarmineOfManyTalents]

May I please ask for some help with the following?

2004 Nissan Quest SL, 3.5L
Vin 5N1BV28U74N359153

Problem: Car won’t start when the engine is warm, UNLESS I give it gas.

Other observations:
* Car starts fine when cold, and does not need me to give it gas in order to start.
* No engine codes or “check engine” light.
* No other problems with stalling, hesitating, stopping, or lack of power.
* NTB04-063 (recommending replacement of camshaft position sensort) is not applicable to my car, which was built after the cut-off date cited there.

What could this be?
My wife says that the problem started after I did the alternator replacement and the other items in 1) through 4) below.
1) Replaced alternator (new, OEM) & serpentine belt (aftermarket). Alternator had failed.
2) Flushed radiator and cooling system.
3) Replaced coolant hoses. (Removed and reinstalled radiator, as part of the alternator replacement).
4) Refilled the coolant, with a fresh premixed 50/50 mix. Must admit that I did not use the special air bleed procedure. I did bleed air from the bleed port on the ~1” hose which supplies antifreeze mix to the heater.

I did the following work after items 1) through 4) trying to solve the above problem as well as the code P1800. This condition may have been in place before I did 1) through 4). I never checked for codes back.

5) Replaced VIAS solenoid valve (new, OEM). (Had code P1800, weeks ago, and I had it cleared about 150 miles ago). Checked that the vacuum hoses on it were good.
6) Cleaned MAF sensor and several electrical connections, using CRC brand MAF sensor cleaner
7) Checked that no electrical connectors were knocked loose.
8) Checked that air filter is clean. Vacuumed out chamber which holds air filter.
9) Checked for air leaks on hoses and ducts. Can’t find any.

[erod3790]

Have u figured out what the problem was?? I am having two same exact problem.

[CarmineOfManyTalents]

Hi Erod3790,

The problem was that the throttle body needed to be cleaned. After I did all that work, the dealer's mechanic simply wiped out the throttle body and everything was fine.

While it was NOT necessary, I did have him clean the fuel injectors on the car as well.

We have since sold the car, but I wanted to try to help you.

[erod3790]

Thank u I will try that. I've also done the crankshaft position sensor. It did not work. And still will not start when warm at all. And I've also replace a broken pressure switch to the AC condencer and radiator hoeses. All oem Nissan parts and still have the same broblem.

[kmk]

Try recalibrating the trottle body, google the procedure, it is with the key and the gas pedal.