My 96 is starting to give me a bit of a headache. It has been a workhorse in the 4 years I've had it but now she's acting up a bit.

The problem is when I restart the car after driving it for a bit, it will run fine for a few minutes, say 5, then just start running real rough. Hesitation and stalling, etc. If I floor the car a few times it will usually get it running fine again. Sometimes it will start acting up again but oftentimes it will just run fine.

It never does anything if I start it cold and just drive it, only when its restarted warm. My mechanic replaced the fuel pump (probably wasted money) and that hasn't helped at all. I want to do a bit of troubleshooting before I have him keep replacing more parts.

The only code I get is a 0304, knock sensor, which I have gotten occasionally for as long as I've owned the car, especially in the summer.

Thanks for reading.

 

I had similar issues - sort of... I replaced my IACV, cleaned the throttle body (remove it from the plenum) and replaced fuel filter. No more issues.....until a new issue started with slight hesitation. I'm researching this now. But rough idle may be due to IACV or TB being all charred up. But then again it could be a number of things. I searched this board and found a lot of good info.

 

Most maxi problems have to do with MAF, IACV, TB, and the EGR guide tube.
You should clean those no matter what, if it fixes the problem or not. Cleaning grounds helps too.

I had a few very weird problems like not starting at all or running roughly, my problem was the coolant temperature sensor (17$ I think.)

The fact that it happens only while warm is what makes me suspect the coolant sensor.

 

Thanks for the replies.

It doesn't happen when the engine is hot, only when it is restarted while hot. I was driving the car for close to 2 hours continiously this morning and it drove like a top. Then I shut it off for 25 minutes or so, restarted it and the hesitation started within 5 minutes.

Will any of the sensors only take a reading at startup? Pretty doubtful I suppose. Does this even seem like a sensor issue or something mechanical? Would the Fuel pressure regulator act strange in this manner?

I guess my next step will be to clean off these likely sensors. Whats the proper method to test and clean them??

 

I bought my 96 Maxima from a friend who was driving it like that for like a year, had six or so mechanics look at it and all stumped. Here's what I did to rectify the problem, and I still havent put a dime into this car.

I cleaned out the carbon and crap all up in the throttle body, put it back together and for a couple days kept searching and troubleshooting, finally I pounded on the MAF sensor box and the idle started moving, so I took out the chip in the MAF (where the plug goes into the sensor) when you unplug it you;ll see four phillip screws, remove em and pull out the sensor, theres 4 metal prongs on the chip, now...on mine it had condensation rust on the metal, i took a soft brush and scrubbed the rust off put it back together, and VIOLA!!! It runs like it came off the show room floor. I was happy, cuz tht i was gonna have to buy expensive crap after reading lots of posts in forums.
I hope this fixes ur problem like it did mine, maybe i got lucky but it takes 15 min to do. good luck.