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Tech501
Tech501, Auto Service Technician
Category: Car
Satisfied Customers: 747
Experience:  38 years exp, ASE Mastertech with L1 Advanced Engine performance
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96 maxima: stumble when i put gas..it park and the engine on

Customer Question

my 96 maxima stumble when i put gas to it or when it park and the engine on
Submitted: 11 years ago.
Category: Car
Expert:  Tech501 replied 11 years ago.
 Check the intake snorkal for any air leaks between the air flow meter and the throttle body.
Tech501, Auto Service Technician
Category: Car
Satisfied Customers: 747
Experience: 38 years exp, ASE Mastertech with L1 Advanced Engine performance
Tech501 and 6 other Car Specialists are ready to help you
Customer: replied 11 years ago.
Reply to Tech501's Post: I change out all the hose that to the throttle body and re clap them I replace all new spark plug with the same one the NGK and also change out i injector with a new one still the same
Expert:  Tech501 replied 11 years ago.

 Run some tests on the Mass air flow sensor.


 



OPERATION


The Mass Air Flow (MAF) sensor directly measures the amount of air flowing into the engine. The sensor is mounted between the air cleaner assembly and the air cleaner outlet tube.


The sensor utilizes a hot wire sensing element to measure the amount of air entering the engine. The sensor does this by sending a signal, generated by the sensor when the incoming air cools the hot wire, to the ECM. The signal is used by the ECM to calculate the injector pulse width, which controls the air/fuel ratio in the engine.



 


TESTING


See Figures 1, 2, 3 and 4


Click image to see an enlarged view
Fig. 1: Backprobe the connector at terminal B as shown (1993-94)



 


Click image to see an enlarged view
Fig. 2: On 1995-98 vehicles, backprobe terminal 1 for testing



 




  1. Using a multimeter, check for voltage by backprobing the MAF sensor connector, as illustrated.


Click image to see an enlarged view
Fig. 3: To backprobe the connector, remove the rubber boot from the back of the connector



 




  1. With the ignition switch ON and the engine stopped, voltage should be less than 1.0 volt.


Click image to see an enlarged view
Fig. 4: The voltage should be less than 1 volt with the key in the ON position



 




  1. With the engine idling at operating temperature, voltage should be 1.0-1.7 volts.



  2. With the engine running at approximately 2,500 rpm, voltage should be 1.5-2.1volts.


It is important to watch for a linear voltage rise in response to increases in engine rpm, up to about 4000 rpm.




  1. If voltage is not within specifications, check the power and ground circuits.



  2. If the power and ground circuits test okay, the MAF sensor may be faulty.










Customer: replied 11 years ago.
Reply to Tech501's Post: would my temperture gauge on my maxima is broken because my friend try to pull the needel out so he can replace the background where it say cold hot would have anything to do with it I also have a custom after market intake. the problem started when i had a shop change out the water pump and one injector and all the spark plug
Expert:  Tech501 replied 11 years ago.

 Maxima's do have a history of having problems with the injecter harnesses. Move the harness around while the engine is running and see if anything changes.


That aftermarket intake can be problems too. It depends if all the original sensors are still operational. You shouldn't do modifications to the computer controlled cars like that. It usually leads to problems.

Customer: replied 11 years ago.
Reply to Tech501's Post: what do you think it the air flow meter gone bad
Expert:  Tech501 replied 11 years ago.
 I said to test it, not replace it.
Customer: replied 11 years ago.
Reply to Tech501's Post: hey I'm sorry for not replying I test the air flow meter it not shorted it work do you think it could be the one of those thing that connect to the spark plug is bad How would you test them to find out if they are bad or not
Expert:  Tech501 replied 11 years ago.
 

TESTING


See Figure 1


Click image to see an enlarged view
Fig. 1: Checking individual plug wire resistance with a digital ohmmeter





  1. Remove the distributor cap, leaving the wires in place.



  2. Connect one lead of an ohmmeter to an electrode within the cap. Connect the other lead to the corresponding spark plug terminal (remove it from the spark plug for this test). Replace any wire which shows a resistance over 30,000 ohms. Resistance should not be over 25,000 ohms; 30,000 ohms must be considered the outer limit of acceptability.


Resistance is also a function of length; the longer the wire, the greater the resistance. Thus, if the wires on your vehicle are longer than the factory originals, resistance will be higher, quite possibly outside the limits.



Customer: replied 11 years ago.
Reply to Tech501's Post: good morning I can I disconnect the all the coil and hook a old spark plug and turn the engine on to see if there spark or not
Expert:  jon_050 replied 11 years ago.

 It's not a good enough test to see if they are failing under load (while working).


Where are you with diagnostics now? If we continue to help you, are you willing to pay Tech501 for all the time he has invested helping you?

 
Customer: replied 11 years ago.
Reply to jon_050's Post: hi i know that the cause of my engine to stumble is one of the coil is miss fireing but I cant seem to find the coil that is defected they all look the same when i pill them out   yes i'm will to pay tech 501 for his help
Customer: replied 11 years ago.
Reply to Tech501's Post: im still having problem with engine
Expert:  Tech501 replied 11 years ago.
 They can be check with an ohmeter. I will get the specs and post them this evening.  

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