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UltratechOne
UltratechOne, ASE Certified Technician
Category: Car
Satisfied Customers: 46
Experience:  General Automotive technician for 39 years. ASE certified. Shop Owner and MBA.
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Altima: I have a 98 Nisson altima with 180k miles. I just changed

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I have a 98 Nisson altima with 180k miles. I just changed plugs, battery, battery cable and fuel filter. My problem is after engine is hot 20min highway driving ..start and stop city driving (5-10 min), then go on highway 15 minutes...Car cuts off after exiting highway off ramp...It will not start right up and "spits and misfires" like the fuel is rich. This was similar problem when plugs were obviously bad .If I wait 5 minutes, the engine will crank and run until i get to work 2-4 minutes. The O2 sensor has not been changed. Could O2 sensor be problem and/or fuel injector?..Tks ..Tim

UltratechOne :

hello tim my name is XXXXX XXXXX i'll be helping you today. welcome to just answer!


 

UltratechOne :

as i understand it after 20 miutes or so of combined stop and go and highway driving your car will quit running.


 

UltratechOne :

it seems to do this after you get off of the highway. you can crank but the engine will not start although it acts like it's trying to start. if you wait for 5 minutes the engine will start and run long enough to get to work. is this all correct?


 

UltratechOne :

the problem sounds to me to be an incorrect input to the computer from one of the sensors. the most likely culprits are these (in order of most likely) 1. mass airflow sensor (tells computer how much air is flowing into engine at a given time), 2. coolant temperature sensor (tells the computer how warm or cold the engine is - if it, for instance, tells the computer that the engine is running at 100 deg instead of 180, the computer could easily dump too much fuel to the injectors for the conditions), 3. air temperature sensor (tells computer the temperature of the air entering the engine - same thing for symptoms as the coolant temp sensor).


 

UltratechOne :

with 180k miles it is very likely that the airflow sensor at the very least needs to be cleaned if not replace entirely. you should figure $100-$150 range on a new sensor. they are not very hard to install.


 

UltratechOne :

both temperature sensors are relatively inexpensive and also fairly easy to change. i would approach your problem in that order. also, if the check engine light has ever come on (or even if it hasn't) i'd take it to a parts house where they will pull the engine codes on it for you for free. if any of the codes correspond to one of the sensors i have mentioned then that is the first one to replace.


 

UltratechOne :

but remember, sometimes sensors are simply incorrect rather than being out of range and so they can fail to let the engine run properly without setting a


code.

UltratechOne :

i am going to switch now to q&a mode so i can make sure you have received all my replies properly. sometimes chat doesn't work the way it's supposed to.


 

once you have read my answers please give me an excellent rating and accept. i am happy to continue to help you with your problem even after you give me a rating so don't hesitate to ask any followup questions you might have. and please let me know which sensor you find at fault. thanks for you question and best of luck! :)
UltratechOne and 3 other Car Specialists are ready to help you
Customer: replied 4 years ago.


Hello bill...Sorry for delay but I could not retrieve any answer for a while and then I was working..1st of all..The car is a 95 and not a 98. I don't know if that makes a difference ?


 


Also the mechanic talked about the catalytic convertor? that sounded crazy..that's why I queried this site??

Customer: replied 4 years ago.


Hello bill...Sorry for delay but I could not retrieve any answer for a while and then I was working..1st of all..The car is a 95 and not a 98. I don't know if that makes a difference ?


 


Also the mechanic talked about the catalytic convertor? that sounded crazy..that's why I queried this site??

that's quite alright about the time. the car being a 1995 does not really change any of my feelings about the direction you should go in fixing your car. still the most likely thing is your mass airflow sensor.
Customer: replied 4 years ago.

Just let you know..you were "spot on" about the mass airflow sensor. It was dirty. Put a new sensor in since the contacts fell off when we removed it. We figure the hesitation/jerking is a result of the sparking occuring at coil due to oil around the engine block. Changing the valve cover gasket after I find a part in junk yard...'ll know how it it runs later..But you answered initial problem well.

thank you and best of luck! come back any time you need help! :)