Any 300zx experts here?
 

Motor in question is the VG30DE V6 in my Infiniti J30 which also applies to the NA 300zx. Does anyone know someone preferably in the Tri-Cities who specializes in these motors? My car is having a problem:

It's having an intermittent no-start issue. It's been at my mechanic's shop for about 7 weeks now. They've been working on it whenever they can. They said they have at least 8 hours into diagnostics. My mechanic doesn't think he can solve this issue. We put on a new Cam Position Sensor and even a MAF sensor and it's still having the same issue. The car does get fuel and spark. Problem is they test and test while the car doesn't start and then it starts randomly which basically renders their tests useless.

We're trying to figure out if it's the anti-theft system but we're not sure at this time. The car can run and work just fine but other times it won't start at all. Car has just over 86,000 KM.

At this point I might end up selling it at a major loss which sucks but there's nothing else I can do at this point. I have way too much going on in life right now. Either the car finds a skilled VG mechanic or a buyer. PM me if interested in this car.

Thanks

https://i.imgur.com/HaXq9BQ.jpg

When I was in the Datsun club many moons ago, lots of guys were running VG30s. Maybe try reaching out to them.

Is Z tune/Monkey Nutz still around?

Too bad Boosty hasn't been around...

-Mark

Probably unrelated to your car, but worth a shot

I have had 2 preludes with the exact same issue, it was the main relay, solder joints would crack, causing in absolutely random no start.

Photo for reference: https://static-assets.imageservice.c...-civic-diy.jpg

Thanks for the suggestions so far.

By no start I assume you mean it cranks but doesn't fire? When you say it has fuel is that all the way to wet spark plugs or just pressure at the rail?

Dead ECU or leaked capacitors... strange behavior can happen with those

Yes it cranks endlessly but won't fire. I'll have to clarify with my mechanic what he means with fuel delivery.

We swapped the ECU to test but it doesn't fix the issue.

When the car starts, do you get any CEL lights?
What type of diagnostics have they done or are they randomly swapping out parts and hoping it works.

To run, the car needs air, fuel and spark.

Ask them specifically what they have done.

This is what i would do.

Turn on the car and listen if the fuel pump is priming.
Y or N

Crank the motor and smell the exhaust for unburnt gas.

Y or N

Pull out one of the spark plug wires and attach a spark plug and place the plug on top of the valve cover. Crank the motor and see if there is spark.

Y or N

Once you know if you have fuel or spark, then you know where to go.

If it is the factory anti theft, then you should get no spark IIRC.

No CEL

We replaced a couple of parts but they did do a lot of scan testing. Im pretty sure he said the car is getting both fuel and spark but I'll ask for clarification. He did mention pulling out the spark plugs.

Best to get that info. Makes a huge difference knowing if there is spark or fuel.

I'm assuming it's a known good ECU, but what about the security module? It'll likely have capacitors in it too that are at the age they'll be drying out or leaking. Depending on how elaborate the security system is though it might be easiest just to bypass it.

We did talk about bypassing it (he doesn't do it but knows someone who might be able to). We just weren't sure yet if it's security related or mechanical.

Update: So the no-start issue seems to have been resolved though we are still monitoring it. I drove it to Mission on Sunday and I'm reminded why I bought the car. Feels at home on the twisters.

But of course as one thing works, another doesn't...

I was leaving work yesterday when the ABS pump ran (like normal) but then wouldn't shut off at all. I just worked an 11 hour shift and wasn't in the mood so I just disconnected the battery for now.

I'm pretty sure it's the relay however I can't fix it just yet so I'd rather pull the fuse. I'm just not sure which one controls the pump.

https://i.imgur.com/rHG0cOW.jpg

(Open image in new tab for better visibility)

There's two 'anti skid' fuses. Both control the ABS but it doesn't say which one controls the pump specifically. Either the 20A or the 30A. I'd rather just the pull the relevant one instead of both.

I'm not an electronics guy...

Neither am I but I can tell you I bought a 90 300zx a while back with ABS light on. It was the ABS module (computer) that failed and I was lucky to get a good one from a wrecker for cheap.

Connect the battery so the pump runs. Pull one fuse. If the pump stays on, pull the second fuse. If the pump shuts off, put the first fuse back.

Google gave me this thread.
Hope it helps.

https://forums.nicoclub.com/abs-light-j30-t44243.html