Hi everyone, this is what has been happening with my 1998 Nissan Maxima GXE with 190,000 miles:

One day when driving I was idling and the RPM dipped very low and the engine turned off. I was able to turn it back on with no problem. A day or so later I'm driving again and the RPM fluctuates as I slow down the car to roughly 15mph or less. It died as I came to a stop after the RPM fluctuated and dipped below 300. I did not drive my car for a month after that. I have my Dad come check out the car since he used to be a mechanic. When he looks at it, the car runs smoothly, no RPM fluctuations, everything works great. Regardless, we change the fuel filter and refill the car with gas, thinking it could have potentially been a bad batch of gas. The car works great for 2 days then has the same issues of it fluctuating and sometimes dying when coming to a stop. I then checked all the wires I could see looking down at the engine to make sure none of them were loose. The car drove great for a day then had the same issues as before.

I decide to risk it and drive 70 miles home because the car had been fine for a couple days when I was test driving it. Ten minutes into my drive the RPM starts fluctuating lightly (but mostly slightly dipping), even at highway speeds. When I applied more gas the fluctuations subsided. I drove like this the whole way home, but whenever I came to a stop the RPM significantly fluctuated and one time completely died. I could not start the car until the 3rd attempt, at which I gassed it hard and the engine finally fired up. I drove it home and it sat there for 3 weeks until I got back from a vacation. Upon getting back, I changed the spark plugs to the original NGK model ones, got an oil change, and it drives great. When changing the spark plugs, one of the cylinders had a bit of oil in it and one of the ignition coils had a rubber seal get stuck to the spark plug.

I decide to go back to school 2 days after changing the plugs and do the 70 mile drive again, and everything is going very smooth for 30 miles. I stop at a gas station, turn on my car and it immediately dies. I try it again and it starts perfectly fine. I keep driving and as I slow down for traffic the fluctuations start again. I end up always revving it slightly to prevent the RPM from dipping too low and turning off. When I finally make it to my destination the car completely dies as I stop on a stop sign. I was able to turn the car on and it drove smoothly for the next 5 minutes (including stops) until I got home.

At this point I am very confused as to what the issue may be barring a wire that's been chewed through. Any help would be greatly appreciated.

 

Have you thrown any codes? If so, please share.

If you have an ohm meter, test the MAF. Google "YouTube Maxima MAF".


You may be due for a new/used MAF.

 

... Maf ...

 

^^^^^^ +1 and the reason I keep spare (used) MAFs in the workshop.

 

My check engine light does not come on but it throws a P0325 code, which is associated with the knock sensor. I've been told that this is not the cause of the issue, but if there's more to it than I would love to know.

I will take a look at the MAF.

 

MAF is the primary suspect. But you might also look for a cracked vacuum hose.

 

Excellent suggestion. If the hoses are original OEM, they are overdue for replacement...ends tend to dry rot and crack after 19 years. Always check and replace cracked vacuum hoses before troubleshooting more expensive electrical components.

If the hoses and MAF are original, it's probably time to replace both.