Hey J30 Drivers! Idle/Acceleration Question

[peaceofmindinhim]

Hey all,

First off, I'm not an expert on cars. Let that be a disclaimer of what I'm about to say. I'll try to describe things as detailed and clear as possible.

I have an Infiniti J30t, which I love. I got the car for free from my Dad, and after putting $787 into it to completely replace the exhaust system, including two California Catalytic converters (damn you California for your stupid laws), it now runs quiet (you could hear it down the street before!).

Anyway, for the past few days, the car has been idling funny - at stop signs, occasionally the idle would surge, and then dip (almost 0 RPMs) as if it wanted to stall, but it wouldn't stall. No shuddering though when this happened. This would only happen occasionally, and I was never able to replicate it on command.

Also, this afternoon, I was stopping at the mall for some pedestrians, and the car started to surge (or rather the idle surged), then dipped, surged then dipped, even though I had my foot on the brake. This happened for about 3 seconds and then stopped.

Lastly, I was pulling into my subdivision today, and I pressed down on the accelerator, and nothing, the car wouldn't accelerate past 2 MPH. The car tried to, and it acted as if it were out of fuel - the car surged, then dipped, surged then dipped (I hope that makes sense...). Again, the best way to describe it would be how a car acts when running on fumes.

I put the car in Neutral, and then floored the gas pedal. I brought the RPM's up to 6,000, and then let them go back to zero. I then waited a few seconds, and put the car in Drive and pressed the gas pedal. I kid you not, I was kinda thrown back in my seat as the car took off. I went up and down the street, opening her up, and I'm not suffering from the "just got the car back from the shop she runs amazing now" syndrome - my J really runs better. I took it on the highway, and floored it - and drove it hard for about a mile or so to the next exit.

At the next light, the car was idling just fine, no more roughness. I drove it another 15 minutes or so, just to make sure, and encountered no more problems along the way.

So this leads me to ask: what's causing all of this? Oxygen sensor? Fuel pump? Fuel filter being clogged? Clogged fuel injectors? Did I clear something out when I floored it in Neutral?

I did some research on O2 sensors, and I'm familiar with their symptoms now. I was thinking of replacing the sensor, but apparently there are four sensors on the J30? Is this an easy job, or a pain in the butt job? I don't have a lift. Also, I probably shouldn't be working on my own car if I'm asking questions such as this, correct?

I'll send free Redbox codes (once I get a new batch) to anyone willing to help!

Also, are there any Infiniti experts in the Inland Empire, Southern California area?

[yodawill2000]

First thing you should do is put a bottle of Redline SL1 in a half tank. (Pep Boys Carries it here in Texas.
Then after a 100 miles or so replace the fuel filter. Then see if it stabilizes.
I did that when I bought mine and the stuff that dripped out of the old filter was NASTY !!
While your at it clean the MAF sensor with some zero residue MAF cleaner.
Whats the color of the transmission fluid ? use a white paper towel and report back. Pink ? dark pink ? Brown ?

Did your Dad keep the recommended maintenance schedule up ?
Whats the mileage ?
Sorry to play 20 questions, but there's a few different things that can cause those symptoms.
Welcome to the J30 World !!

[peaceofmindinhim]

Yoda,

Thanks for the reply!

As far as I know, scheduled maintenance was kept on the car.

Trans fluid is nice and pink.

MIleage: 164,243

I'm going to go take it for a drive today and see how it responds. I need an oil change anyway. Also am going to have the fuel injectors cleaned.

Eric

[J30inthe sun]

Sounds like exactly like the problem I had a couple of years ago. The Mass Air Flow sensor was bad. I replaced it & all has been well since:

strange-idle-this-morning-t409802.html

[peaceofmindinhim]

So here's an update of what I've done to my car so far, and the results:

Oil change - desperately needed one (I know, I know...I don't deserve nice things if I don't take care of them).
Fuel Injectors cleaned - both through the lines, and additive added to the gas tank.
Transmission fluid topped off (was slightly low when tested hot).

Let me tell you, it's been two days since the work was done, and my car SCREAMS! Especially when semi-cold, the rear tires squeal a bit and it breaks on turns. It's like driving an entirely new car.

That said, I still don't have the same OOMPH at times after the car is warmed up, but it's not as bad.

I'm starting to love my J30t a bit more.

Still going to have codes ran on the car to check on Knock/O2 sensors.

Also, I need the A/C fixed. Compressor kicks on, and the pulley turns, and I charged with R134, but still no cold air.