Does anyone have experience with have hard starts with no IAT sensor? My car currently does not have one (I am getting one at the junk yard this week), and it is also having trouble starting. By not having one is the ecu just making the a/f very rich on start up? The car turns over fine and will fire up eventually but it takes it a while...like its a carb or something. Anyone know if there is a relation between the two? Thanks for the help.

Carson

 

IAT sensor only measures air tempature. It should not effect anything.

 

so that would not effect the fuel mixture....I tend to think it would run rich since it cannot monitor the air temp., am I wrong?

 

it does not affect a/f ratios at all. it is obviously monitored by the ecu but only maf and o2 sensor determine a/f except at WOT when the maf takes over.

 

the Haynes manual lists the IAT as one of the causes of a rough start. Whether or not this true I may soon find out. I almost replaced every single sensor but this one and still getting a rough start

 

Yeah, thats what I just looked at and I saw the same thing. It is listed under causes for trouble with hot starts. I am throwing a code for the sensor, which makes since, since I don't have one....I will find out monday if that is my problem

 

maybe our ecu compensate differently but with mine disconnected it starts the same. blu's 4th gen also had a damaged IAT with no issues with rough starting aside from the JWT problems that were smoothed out with the stock ecu.

 

yeah I hear what you are saying...but mine does not exist. I hope my problem is just this...but I really don't know. Does Blu's car even start with a Key or does he have push button....I forget what injectors he is running.

 

theres no way, the chitlins manual states that this sensor is for feedback only and DOES NOT affect the engine performance in any way whatsoever. . . sides, mine is totally disconnected and hanging there and my ride starts fine.

 

it wont effect engine perfromace but it will give you hard starts read the nissan service manual it works with the electronic igniton system
i had the same problem and it was air intaKE TEMP SENSOR

 

You Have The Crank Sensor Pos , Ref And The Camsensor Engine Collant Temp Senor Also The Coolant Temp Sensor Sending Unit And Air Intake Temp Sensor All Of The Sensor Detemine Hte Proper Igniton Timing For The Computer To Use To Start Your Car Properly (adjust To Air Temp Each Time You Start You Car Hte Temp Out Side Changes So The Ecu Uses All Those Sensor To Male The Proper Adjustment If There And Interruption In The Ignition System It Will Hesitate To Start Because Its Missing A Reference Signal "distribute Interuption"

 

I'm going to go out on a limb here and say it does have a tendency to start hard w/ a bad/ no ait sensor. i just switched from the ram air to injen cold air and my ses light came on. just checked it out. code 0401. AIT. and i noticed that on the test drive, when starting the max it seemed it took about twice as long to fire up, like when im low on fuel. then i come on here and see this thread. so im really thinkin it is the ait. should i play with the one there, or just replace it? it can't be that much right?

 

This is so funny i just found this thread... my AIT is disconnected and for about a week or so my car wouldnt start it would just sit and crank and crank and literally i had to give it gas to kick over..and finially from cranking so much i blew the starter completely and here i am sitting here waiting for my parts store to get the new starter in by noon ...... and i have work at 1 so that gives me like 15 minutes to put it in and get ready for work.. any way i am going to plug the AIT back in so i will let you guys know if that fixed the problem..

 

The FSM states that the ecu compares the values received from the IAT sensor and coolant temp sensor and that they are used together. Several people have said that their coolant temp sensor was at fault for hard starting. They are both thermistors so I wouldn't be suprised if IAT could be a possibility of a hard start. The original question had nothing to do with engine performance it had to do with starting the car.

What does the chilton say its purpose is?

 

I was not able to find one at the junkyard yesterday, so I will either order one from nissan or get one at advanced this week. The car turned over forever before it started yesterday after I ran the car for about 2 hours straight. I'll report back once I get a sensor.


*edit* also when the car finally does turn over I get smoke coming from the tail pipe, I have never gotten out of the car to see what color it is but I am guessing it is gas.

 

im an idiot.

so when i swapped the intakes and i pulled the code it was because the IAT was not hooked up all the way. the plug is really really stiff and i didnt have it connected. but my hard starts are gone. so yeah this is one reason for a hard start, prob not the only though.

 

cool, good info, I hope this is my problem. Or I am going to burn up another ignition switch and a started while I am at it. I got tired of looking for one used so I ordered one from the dealer today. My parts guy told me it should be in by the end of the week, so hopefully I will have good news later in the week.

 

I'm posting this msg to get 1 of my 15 required posts. I have a question and I need to post a new thread. I'm sorry, it sucks, I'm sorry.

Trav

 

I put in an IAT sensor.....and it did not help. So while I was having some welding done on my car, the guy working on it could not get the car to start after he finished so he had to bump start it and leave it running in the parking lot. When I went to get it he was telling me what was going on and he could not get it to start with a key, so I just thought that it was turning over forever and would not catch. I was wrong, I pulled into Auto Zone after I left there, once I was done at Auto Zone I came back out to start the car and I got nothing, the starter was not turning over at all. Luckly I was parked on a hill, so I kick started the thing in reverse. Long story short my starter was the problem. I replaced my starter that day, now the car fires right up. Thanks for the suggestions everyone.