Mysterious Problem with Infiniti J30

[bobbygrady]

My Dad has a Infiniti J30 with about 160,000 miles on it. The car will run fine for about 10-20 miles and then just stop running and WON'T RESTART. It's NOT THROWING ANY TROUBLE CODES AT ALL. So far, they've replaced the Mass Air Flow Sensor, the starter, and the Igniter(?), not sure what the igniter is. He HAS TO HAVE THIS CAR to get back and forth to dialysis because he needs a kidney transplant due to them shutting down because of diabetes. We live in the Louisville, KY area. He's been sent to four different mechanics who thought they had it fixed but they obviously didn't. ANY AND ALL HELP WOULD GREATLY BE APPRECIATED.

[fourdrinie]

are there any aftermarket alarm systems or ignition disablers on it?

[bobbygrady]

No sir. It has the original security system. Which makes this eve more puzzling/

[fourdrinie]

When u say it doesn't restart...does it crank and not turn over? Completely dead, no start? Give us a clue...

[bobbygrady]

It cranks and won't start. But, if you leave it alone for an hour or two, it will start just fine. Could it be Fuel Pump Control Module?

[fourdrinie]

the fuel pump and module usually either work or dont work....
might want to switch around the fuel pump relay in the engine bay on passenger side...give it a rap and see it if clicks on..
the other thing might be the engine coolant temp sensor...
what year J30 and does it give any codes?

[J30tChumpCar]

It needs to quit for the mechanic otherwise its just guessing, there are many possibilities such as a bad fuel pump could be overheating.

[bobbygrady]

The crazy thing is, that it has quit on the mechanic and they are still grasping at straws. With him fighting his diabetes and his kidney problems and having to taking dialysis 3 times a week at 4 hours at a time, this just makes it even MORE EXHAUTSTING for him. That's why I'm reaching out to every message board out their trying to find the RIGHT possible mechanic whose dealt with these problems in the past.

[GerryO]

Some engine problems/codes don't cause the CEL to turn ON. Has the mechanic checked for stored codes? Find a mechanic who knows the 1990-1996 Nissan 300ZX.

What spark plugs are installed and how old are they? The EGR tubes are probably clogged.

My ECM seems to display only one at a time, with another popping up only after the cause of the first one has been addressed.

Check for vacuum leaks. Vacuum hoses are getting brittle and starting to crack. Due to a vacuum leak, my engine would idle when it was cold, but not after it had warmed up.

Know for a fact that the engine will crank, but not start if the TPS or one of the connectors near the battery are disconnected. One bad wire/connection is all it takes. Disconnect, clean and remake connectors under the hood, coating contacts with dielectric grease. Clean the battery terminals and cable connectors. The good news is that a lot can be accomplished by replacing inexpensive parts and simply cleaning others.

And then there is always this:

http://www.pexcom.com.au/z32cms/e107_pl ... ontent.335

Download and print this out for your mechanic:

http://www.mdsmarthome.com/z/Z%20Tech/Z ... 20Idle.pdf

Good luck!

[J30tChumpCar]

Great info but I fear this is more then a idle control issue.

[GerryO]

It cranks and won't start. But, if you leave it alone for an hour or two, it will start just fine. Could it be Fuel Pump Control Module?

Cranking, but not starting is about the most extreme type of idle control issue imaginable.

With my vacuum leak, the engine would start and idle until it was warm. When it was warm, with the idle control system then OFF, it wouldn't start and keep running unless I kept some pressure on the gas pedal. Backing the idle speed adjustment screw almost all the way out temporarily "fixed" the problem, allowing me to listen to and work on the engine while it was running.

Unrelated to the vacuuum leak and over the about 20 years that we've owned our J30t, a couple of times I've had to crank the engine for an extended period of time with the accelerator held to the floor, in order to get it to start.

[bobbygrady]

Thanks for all of the variety of information. I've passed it all on and waiting to hear what the prognoses ends up being. I'll keep you all posted.

[fourdrinie]

Any word of a solution?

[BunnyHop]

my 92 M30 would just shut off intermittently.
After some research, discovered it was anti-theft.
Electrical mechanic disconnected it for me, but I'm now having trouble with the doors and locks

[jertapper]

It cranks and won't start. But, if you leave it alone for an hour or two, it will start just fine. Could it be Fuel Pump Control Module?

Cranking, but not starting is about the most extreme type of idle control issue imaginable.

With my vacuum leak, the engine would start and idle until it was warm. When it was warm, with the idle control system then OFF, it wouldn't start and keep running unless I kept some pressure on the gas pedal. Backing the idle speed adjustment screw almost all the way out temporarily "fixed" the problem, allowing me to listen to and work on the engine while it was running.

Unrelated to the vacuuum leak and over the about 20 years that we've owned our J30t, a couple of times I've had to crank the engine for an extended period of time with the accelerator held to the floor, in order to get it to start.

Same here. This would often be the case when I started the car and moved it just a few feet to get another car out of the driveway so it was only running for a few seconds. Starting it up again and I'd have to deal with this. Also, it would happen when starting the car and I would think it was running and so I would stop pushing the key to the start position and back it off but the engine wasn't fully started. After that I would have to do the pedal to the floor trick.

I also had a vacuum leak issue one day. Had called the tow truck after coming back out from eating and the car wouldn't start. I found the vacuum line detached and cracked at the end (it was running when I drove it there an hour prior). I cut the cracked bit with my knife and stretched it back on...voila. I replaced it later...and kept extra in the car. I think it was the one going in near the MAF sensor. There are two there but it was certainly on the driver side front area. Called tow truck and told them not to come. That was a nice feeling being able to find and fix such a strange problem and go from broken to working that quick.