when the temp drops below 40, i have to blip the throttle a few times just to keep it running. If I just start it up, it stalls (unless im in the garage). Could this be an IAC problem? After it settles in on idle I don't have any problems at all. I did notice that it doesn't have a higher idle when its cold though. Most cars I've had will idle around 1500 rpms until its warmed up a little. Should I have a higher cold idle than 800 or so rpms? Idle is rock solid after its warm.

anyone else having similar problems?

 

have solved this on a few cars by thoroughly cleaning the IACV and TB. take them both off and clean them. dont use the Motorvate method. remember to use new gaskets.

 

Check you coolant sensor to see if it is within range. Tells the computer the water temp. Also, check the High Idle to see if it is working. (see my post about this http://forums.maxima.org/showthread.php?t=549320.) It might need to be adjusted.

I think my problem was masked by the dirty TB and IAC. Once I cleaned it, I had the opposite problem! Check to see if yours is moving from hot to cold. It is the piston just under the throttle cables, rotates the high idle cam.

 

dont adjust your idle. and if it stall when cold its not the temp sensor.

 

Does the temp sensor only fail open? Resistance drops as temp rises, so that would make sense. So if the resistance goes infinite (max cold), the computer just sees it as "cold".

If it shorted out, I could see a cold start issue, as the computer would see it as no resistance or hot???

 

The intake air temperature sensor and coolant temperature sensor act very similar:

Intake air temp sensor
at -10 deg C (14 deg F), resistance = 7.0-11.4 kohms
Coolant temp sensor
at -10 deg C (14 deg F), resistance = 9.2 kohms

There is a temp sensor on the EGR valve also. The EGR valve may be partially open?

There is a note in the FSM states the intake air temp, egr temp and fuel temp temp sensors are for diagnostics only and not used to run the engine. Then this only leave the coolant temp sensor.

 

thanks for the input guys.... I am not touching the idle, this isn't an idle problem. This is a start then stall.

When you start your cars in the morning, what RPM does it idle at when cold? 1500?

After I keep it running, mine settles around 900-1000rpm

I am really thinking this is the IACV, I'm going to clean it tomorrow.

 

question:....have you done anything at all to try trick the computer that the air is denser and cooler thus making more power.? If so...what will happen is that when the temp does drop in truth, the computer is so loss now and it will be telling the computer that the air is a certain temp when infact its lower. i cud be wrong.

 

warm idle = 6-700. higher idle and hard start = your original thought. clean both TB and IACV and you should be fine.

 

cleaned the IACV out from top to bottom, stripped it apart and cleaned everything. Cold idle is now at a solid 1200 rpms, but it has also warmed up to 50 degrees here. Guess I'll have to wait til it gets cold again to see if it really helped at all.

The IACV had heavy carbon deposits, so it definately didn't hurt.

 

well lets hope your good to go.

 

had a cold day finally..... and....... it didn't fix it...

not sure where to go next

 

Dips before 40? Try -20 in Chicago. That's a true test of your Maxima. How is your throttle cable adjustment? Did you ever mess with that?

 

when was the last time you changed the fuel filter ?
its known to make the car start and stall right away if its plugged especially in the cold

 

throttle cable is tight with no slack... have not replaced the fuel filter

filter would make sense... as soon as I blip the throttle it keeps everything running as if it wasn't getting enough fuel

 

there you go, try that, make sure you get the bigger 1996 300zx FF it will last you twice as long

 

I had the same problem, it also cropped up when at high altitude, 6000 ft. The spark plugs had not been changed for 100,000. Changed them and it starts and runs fine.

 

your sig looks like a vq30 w/ a vq35 cover laying on top of it. or did you really do the swap?

 

LOL that is most definitely a 35 cover on a VQ30.

 

^^^ BUSTED, I'll take my cover and multimeter back. kthxbye.

 

We can take it to the streets and I'll show you. 3.5>3.0 Do you guys not see what the question is in my sig?

 

unforgiveable....