Still A Cold Start!!!

[k3smostwanted]

i have posted this problem a couple of times last winter but here it goes again because its BACK AGAIN!!!

ok...everytime my car is completely cold i have to start and then immediately have to push on the gas to keep it from dying. i have to do this until it the temp guage gets to the "C" (cold) line. as soon as it gets to the C line i can let go of the gas and it will idle fine. if i let go of the gas before then it will die immediately. once the car is completely warm and i shut it off, i have no problem starting it again. fires right up everytime as long as the engine is warm. BTW this is when it is fairly warm ambient temp. anything above ~45 degrees.

now when it is below ~45 degrees i have even bigger problems. the car fires right up on the first try and then immediately dies no matter if i push down the gas or not. i have tried evreything to get it to stay started on the first try. anyways, so the car dies after the first try. now it will not start at all. it wants too but doesnt. it kind of just slowly cranks. it kind of sounds like this. chug......................chug..................ch ug.........chug........chug....chug....chug...chug ..chug..chug.chug.chug.chug. and then finally STARTS. that whole process of the CHUGGING takes about 3 or 4 minutes before the engine finally gets turning enough to completely start. again, once it is started and warmed up it does fine. even when i turn it off, if the engine is warm it will fire right up everytime no matter how cold it is. i am posting this because i am fresh out of ideas. the IACV is replaced because of another problem that that solved. ECU codes say everything is fine. spark plugs are fresh. air filter is clean. it isnt a big deal this winter because i have a second car but it is just REALLY frustrating.

also, every once in a while my car will idle high after a hard run or i have been driving it for a while. doesnt do it everytime but sometimes. i have a feeling that these 2 problems may be related.

i described it as best i could at this time. if you need further details maybe i can supply them when im not so tired.

thanks in advance!!!

[Hodo]

OK I think it could be the IAT sensor. Wrong reading on the IAT, the engine thinks its REAL DAMN cold and floods the engine with fuel to compensate or cuts fuel to compensate.

[k3smostwanted]

intake air temp. sensor???? is that what IAT stands for, probably something like that...could there be another name for it?

[k3smostwanted]

nice, but what does that have anything to do with what i posted...thread hi-jacker!!!

BTW: thats is a huge f***ing turbo!!! what kind of motor is that fellas???

[Hodo]

yes IAT stands for Intake air temp sensor. I cant think of another name by which it might be called. Ford and Volvo call it the samething. Maybe IAS? or ATS?

[masood]

that was supra's motor with T-88 Greddy single turbo.

[k3smostwanted]

Originally Posted by masood

that was supra's motor with T-88 Greddy single turbo.

yeah i reposted it in its own thread so everyone can see it. nice find though!!!

BTW: thanks hodo!!! ill search for it. i cant find anything called the intake air temp sensor on the z32.

[Hodo]

Just thought of another name it maybe called. Ambiant Air Temp Sensor, or AAT or AAS.

[k3smostwanted]

ok i will look that up next. thanks again.

[DeleriousZ]

what weight of oil do you have in there?

[k3smostwanted]

10w30, that was the only weight i was told to put in. should i try moving to a thinner oil???

i am pretty sure that it is a more serious problem than the oil but you never know.

well i just did a little research and the only temperature sensors i could find were the fuel temp, coolant temp, and the EGR temp (only available for california models). got any ideas on where to look??

[DeleriousZ]

that sounds about right, but it sounds like it could possibly be a fluid/friction related problem... what fluids are there that could prevent an easy startup.... oil is the only one i could think of... transmission shouldn't have anything to do with it... coolant wouldn't... maybe fuel issues? might have something to do with a line that's running around the engine that flows better when heated up?? i'm just tossing out long shots... no real clue

[k3smostwanted]

well i think i have narrowed it down to fuel delivery or a sensor that reads the engine temp so the ECU knows what kind of air-fuel mixture to send to the engine to get it to start.

i kinda narrowed out the fuel delivery just because of the fact its getting fuel because it will flood itself. so i am left with a sensor. does anybody know if the MAF does more than just read the amount of air that is coming into the engine??? maybe the MAF reads the temp of the air also??? because i searched for any sensors that could possibly be related and i had no luck. i came up with coolant temp and fuel temp.

[Hodo]

hmm good question about the MAF. Not sure on Nissans. Not likely but never know with Japponese companies. I know Volvo and Fords dont use the MAF for temps.

Also how could does it get where you live. 10W30 may not be a cold enough oil for you. I know in NC I use 5W30 Synthetic. When I was in AZ and TX I ran 10W30 synth.

[DeleriousZ]

maybe i should think about running some 0w30 if there is such a thing... it can get down to -40 degrees celcius where i'm living.... most cars just won't start when it's that cold... i suppose i should test if my block heater actually works.