Today I started the J30, drove 1 mile and it suddenly kind of hesitated/jerked for a second when hitting the gas and then just died. I rolled to a stop, turned the key off, waited 30 seconds, then it started right up with no problem. Drove 3 blocks and then the same thing happened again. Started up instantly fine again. Drove 1/2 mile and then it happened again.

After that I drove it for a couple hours, running errands, never happened again. I maybe felt that small hesitation once or twice when accelerating but nothing else. No dash warning lights ever came on. Any ideas what could cause this?

I got the 93 J30 , and similar things like that ending with no starting in a couple of weeks. So it was an
"intermittant " problem , ended up being fuel starvation due to , as in both our OLDER vehicles, fuel pump relay -hidden behind drvr's kick panel , brown colored and paired with a "tailight -bulb-out" relay on a bracket and behind that silver sound-matt stuff. Contacts became more & more marginal till it wouldn't conduct enough current yet, it DID CLICK OVER- closed position ! Hearing it energized & clicking I almost overlooked - but as a professional electrician , a couple of further tests of the f/pump ckt I went back to relay upon getting virtually NO current flowing through the closed contacts.
Other than removing kick panel , and I believe some module , then the matting , and relay cost me $16 - it's a relatively clean and easy repair , better than "shotgunning" a ton of engine sensors ,IACV,MAF ya know. So ,kinda
hope you got what I had !
But CHECK ANY CODES first.

Thank you, I will look into that.

if you can get a cheap fuel pressure gauge, i.e. harbor freight....all you need to see if there is any fuel pressure, doesn't need to be very accurate.
next time it happens, hook it up and see if there's enough fuel coming out from the pump....
just a thought..

As fourdrinie summed up - check pressure , which can be done fore and aft of filter on passenger wheel well next to motor , keep in mind though maybe on the INTERMITTANT part of the failure curve ,whereas I could actually feel the swell (manual suggests squeezing line too) on line going into rail , whenever fuel was getting in at right psi. As I noted it may be less and less @ 100% pressure.You know someone can turn key for that 5 sec. prime -you'll feel it while you got your thumb on that line! Good luck.

Today shortly after startup I again had hesitation when accelerating a few times and then it died. But again seemed ok after the car warmed up.

I got an ECU code 34 Knock Sensor. I tried searching on that but got nothing even though I thought I'd seen discussion on knock sensors in this forum before. But anyway, does a faulty Knock Sensor sound like something that could be causing the problem?

Also, I was digging around for that fuel pump relay but didn't find it. Is it on the left side of the footwell near the fuse box? Or in front of the brake pedal area? Or?

Relay is brown & paired with another one (gray?) on bracket BEHIND/UNDER A LOT OF THINGS L. side footwell within 3" of fusebox @ that location.
Yup possible Knock Sensor can be responsible , I believe INSIDE /UNDER INTAKE!!
VG30DE motor , I have one too ,I had bad KS ,didn't register on ohms properly and gave code.
I did my own "new OEM part relocation" by removing the nice plastic rectangular fancy eng. cover , and I used the MOST CENTRAL BOLT (hexbolt) LOCATION using longer depth bolt holding VERY firmly the new Knock Sensor , check / reset base timing after test drive = Perfect. I didn't like some of the ideas as seen on youtube and wherever , some required drilling head or block . Like I figured the manifold transferred the "knock energy" fine , registering proper to the ECM!

if you send me your email address, through a PM, I can send you a few pictures of how the external knock sensor gets set up.
you'll need a knock sensor, new knock sensor connecting wire, and bolt - m8 - 1.25 x 100mm

fourdrinie

Ok, I have cleaned the MAF, cleaned the throttle bodies, and replaced air filter. I bought a new knock sensor and harness for it (wrong connector which I see is a common issue), and relocated it (thank you guys). Also found a loose ground screw related to the KS and tightened it.

Problem still there. It has happened enough times now that I have a good understanding of symptoms. It idles fine, smooth. Runs fine on a cold start for 1st 4 minutes until just arriving at operating temp. Then as I'm driving along it starts hesitating and often stalls/dies. Starts up again instantly. Over the next 3 minutes it might hesitate/stall/die once or twice more as I'm traveling ~30mph. Then it's fine from then on until the next day upon cold start when the whole cycle repeats. Actually today for the 1st time it was somewhat hard to get restarted after it died, so maybe the problem is getting worse.

After reading through many back threads I've decide my next plan of attack is to replace the MAF. After that I'll look into fuel filter, fuel pump relay, coolant temp sensor, throttle position sensor, clean IACV. Figured I should replace PCVs too. I'm skeptical that any of these things will be the fix, and I know that throwing new parts at a problem is not a great strategy but that's the plan anyway. Appreciate the help thanks.

Please do tell us when and if you find the culprets , I have 93J and experienced 3 different yet similar kinds of hesitation , MAF once (got pick a part bought & tested 3 for eliminating in future prob's) , Ign timing - upped it to 15 BTDC ( was due larely to Tim. belt stretch wear , drives like new after belt & pullys replaced) , BUT there was / is the mysterious "Infiniti hesitation' , was the worst like yours , and I NEVER had a clue to what specifically ended that one - except it seemed to be upon heavy maint. where I did put NGK Irridium - one COLDER (chk the Gap) , among oil/filter, K&N A/F , resetting IACV per idle RPM spec. Did the O2 2000 RPM using ECM screw "twist" check per FSM too. I dunno too .
One thing I always wondered due to 2 prev owners did few oil changes and I believe I also at the time did that Motor flush crap - and seems like maybe was CLOGGED Cam Advance passages , because a year later when a wire broke on Adv solenoid Bank1 ,I pulled Bank2 conn. for shtts & grins and GOT THE SAME SLUGGISHNESS as that "mystery Infiniti Hesitation" stall ?? FWIW Hi-Mi Valv 20-50 ( AZ) no problemo .

Since it's not a 97+ with obd2, it's hard to tell.
If you had a scanning device that would keep track of fuel level trim you would be able to tell if the MAF was giving a bad signal (too much or too little O2 to the O2 sensors/fuel injection system.
i have purchased this item from Ebay and it works fine
https://www.ebay.com/itm/New-Mass-Air-F ... Swvg9XT5Im
not sure if it fits your 94, but check it out (it says 95 and up)

Yes I found one from that same seller (based on one of your old posts) for $20 so I figured it's worth a shot.

it will let you know right away, if it fixes the problem....but these cheaper parts usually don't last...
However, my replacement MAF has been just fine......

let us know the results

if the MAF replacement doesn't fix it, the other thing I was thinking of is the transistor ignition module that sits on top of the engine, close to the firewall, passenger side, under the crossover brass pipe. Black plastic unit, with two plugs, one on each side.
It controls the spark to each spark plug...might be intermittently faulty.

You'll have to find it used, on Ebay, junkyard etc.

If you need a picture of it, or part#, or can't find it, let me know via email.

The MAF arrived today, I installed it, went for a ride and the car didn't stall. I thought maybe I felt some minor hesitation but not really sure so I'm going to test it for a couple more days. So far so good, keeping my fingers crossed.

so, you should change the subject of this post from "Weird Stalling Problem" to "Typical J30 Stalling Problem."

The MAF is the most typical defect I have seen on this forum since I started driving my J30 in 1999 (97 model).

If the new MAF fixed your problem, consider this a cheap fix for around $20.

I purchased an extra MAF for another $20 that I keep in my car, just in case of failure....cheap insurance.

Ok I'm back to report on the Final Solution to this stalling/hesitation problem and summarize what I did to fix it. Four of the things I tried did nothing to help: new knock sensor, clean throttle bodies, clean MAF, new fuel filter.

I then bought a cheapo $20 MAF that fixed the stalling problem but the car was still hesitating, mostly when accelerating. After reading many similar stories online I decided to buy a better MAF for $125. The car now runs like new again, no hesitation or stalling whatsoever.

Thanks for the help you guys, especially fourdrinie for good advice. Really appreciate this site, it's a great source of info.

can you post the brand and where you bought the good one from?

Delphi from RockAuto

after talking with Kurt (Doughnut) about the hesitation problem, which was fixed with a better brand (Delphi) MAF.
I realized my 97 J30 was having a similar cold hesitation issue with a cheap Chinese made MAF I had bought. I even bought two of them just in case.
I found a Delphi brand MAF on Ebay for under $100...replaced this am, the cold hesitation is gone....

If you can afford the Delphi brand MAF, I highly recommend it over a cheap Chinese version.