Questions and Answers
Altima Stumbles
Q. Dear Mr. Ciulla, The car in question is a:
1998 Nissan Altima
2.3 litre
Automatic transmission
71,000 km or 44,000 miles
Fuel injected
Power rack and pinion steering
A/C and Cruise
The car is a very clean recently purchased used car, that came off a lease. I mention this because I feel the car has not had just as good care, as it would have had, had I owned it from new.
When I drive the car at 36 to 39 mph, and almost take my foot off the gas pedal, the car starts to miss or buck just enough so that I can feel it.
I just installed new NGK platinum spark plugs (.044 gap), and a new air filter, but this did not correct the problem.
It runs just fine except for this small problem.
Could the throttle body be caked up. If it was, then as I take my foot off the gas, the car would be starved for air and fuel. I'm not even sure of the car has a throttle body, just a wild guess.
Erik (a senior with a slightly hesitating motor.)
I want to thank you, for the really fine job you are doing, helping thousands of people, by throwing light onto their car problems.
A. Thank you for that nice comment. I do try to be as helpful as I can and I hope I can be of help to as many as I can. I wish I could look at everyone's car and give better answers than I do, but it's just not possible. So I do the best I can with this site.
Anyway, as far as your car goes there is no throttle body, that refers to a type of fuel injection system. There is, however, a throttle chamber which is what you mean. The first thing I would do is give the throttle chamber a good cleaning. Most times this will cure a stumble such as you have. The other possibility is the Throttle Position Sensor (TPS). Nissan has had problems with these and the symptoms are indicative of a bad TPS. It can be tested with an ohmmeter, but the best way to test it is with the Nissan CONSULT scan tool.
The one drawback of buying a car off of a lease is that they generally don't get the best of care. I mean why sink money into a car that isn't yours and that you're going to turn back in before the warranty runs out?
Additional Information provided courtesy of ALLDATA
