injectors j30

[madmax88]

My injectors failed and had them rebilt . now the j is some times hard to start , is it the injectors? the car runs good thou. maybe a slow leak, spark plugs, air vacuum valve, fuel pump seal, I just dont know.

[Q451990]

Any pattern to when it's hard to start? I put remans in from a place called Python Injecton back in 1997 or 1998 and had a bleed-down problem. The car would start fine first thing in the morning, but after a hot soak (an hour or two after driving, and then a re-start) I'd have trouble starting it and some blue smoke. Apparently the injectors would bleed down and flood the engine, but the extra fuel would seep past the rings overnight and allow a normal start after prolonged sitting.

Replaced them with factory units and all was right with the world again.

Heath

[Q45tech]

Rebuilt [Bosch of Japan design] injectors [no such thing] maybe cleaning used [junkyard] injectors and saying they are rebuilt.

Never use Python always buy brand new too much chance of a gasoline hydrolock.

[madmax88]

oh no! can I use 300z injectors?

[Q45tech]

As long as they are not the 370cc version found on turbo and Q45.............seem to remember they [90-96 NA versions] are 256cc or there abouts.

[Q451990]

Is there a price difference? I'd call Joe and see if they're the same part number or price. 1-888-216-5328. The injectors are tuned for the runners and intake of a specific engine, but I'm not sure what the difference is between the Z and J engine.

Heath

[madmax88]

j 30 is 280cc

[madmax88]

so 370cc are not going to work?

[Q451990]

I'd think it would mess up the fuel mixture since the ECU is calling for a certain pulse width (injector opening time) based on the OEM sized injector. A larger volume injector would probably put more fuel in at a given pulse width and cause the mixture to be too rich. All speculation, but I doubt that larger injectors would work (or even help performance) without reworking the ECU mapping, cam duration, intake plenum, etc. All of that stuff is tuned to work together.

Heath

[madmax88]

hmm I am going to tt so what than? Im allready tuning the ecu is ok?

[Q451990]

We're getting a litte out of my league here... I don't have much tuning experience.

Heath

[madmax88]

cool

[Mayhem_J30]

considering the pain it is to replace the injectors on this thing get good NEW OEM injectors and worry about it again in another 100K miles.

[VimyJ]

I believe Canada is on the new low sulfer standard (I could be wrong about the whole country). If that's the case, you might not have to worry about your injectors for 200k.

[Eswift]

thats weird, I thought all of the high-sulfer crude came from canada...maybe they just know how to process it.

In any case, injectors from 94+ 300zx NA will work with your stock ECU.

not TT, not before 94.

If you want 370s, you will need to update your EPROM or run a separate engine management system.

Or, you could find a Federal-spec, automatic, TT 300ZX ECU. It will support the 370s, and guess what? The fuel maps are the same NA to TT. just shows how damn rich the NA runs, makes me sick. oh, this will only work if you do not have hicas.

[Eswift]

PS I hope you got full flow bench results back with those rebuilt injectors...

[VimyJ]

I always wondered why the J is relatively hard on gas compared to other V6s. I assumed that the car is just built like a tank and turns highish RPM at cruise. However, I know the main reason for running rich is a function of temperature control. Is that correct? Would it even be possible to remap the ECU for a leaner burn or would that not be compatible with the VG30DE design?

[DAEDALUS]

Us Q guys buy JWT ECUs to do just that. No reason to think it couldn't be done with the J. I would guess the margins are about the same.

[Eswift]

I always wondered why the J is relatively hard on gas compared to other V6s. I assumed that the car is just built like a tank and turns highish RPM at cruise. However, I know the main reason for running rich is a function of temperature control. Is that correct? Would it even be possible to remap the ECU for a leaner burn or would that not be compatible with the VG30DE design?

Nissan's rich mixture intention is basically to avoid detonation at all costs. Extra water, fuel, or alcohol can provide this effect, although excess fuel also ensures the mixture never has a chance for a lean enough condition for detonation at WOT.

As far as remapping,-of course, and by some people's standards [me] the JWT ECus could be leaned out a bit. It is just a matter of how much you want to eat away at the factor of safety. Since there are low-octane maps [used when a knock is sensed] you really dont have to worry about piston soup. The timing can be advanced in many places as well....A lot [25 hp at least] can be gained on the NA engine with editable mapping and a good dyno and wideband lambda setup.

IN any case, the engine was set-up for mechanical reliability, and if you stray away from what nissan intended, i guarantee you will be shortening the life of your internals, unless you put as much R&D into it as they did. BUt what's a rebuild? worth it, I would say.

[VimyJ]

The VG30DE is certainly reliable and still a very good performing engine even after all these years even when compared to the latest designs.

[Eswift]

absolutely, it still can outperform a domestic V6 of the same displacement.

[Mayhem_J30]

absolutely, it still can outperform a domestic V6 of the same displacement.

True, I just wish I had the same torque curve (or torque in general) as most newer 3.0 V6's. Variable valve timing might have something to do with it.

[Q45tech]

Give or take a few percent all equal displacement engines consume the same fuel amount per rpm at highway cruise.

The system must consume 1 part [1 gram] of fuel for every 14.7 parts [grams] of air..........all engines are optimized at 55 - 60 mph to maximize EPA ratings.

http://www.westechperformance.....htmlhttp://www.geocities.com/Motor.../FuelConsumption.htmlhttp://www.mne.ksu.edu/~chapma...x.htm

I don't know of any 2960 cc engine that produces more than 222 lb/ft so 193 lb/ft [stock J30] is a bit off the mark........the louder exhaust of the 300zx NA boost it to 198 lb/ft and the JWT ecu squeezed out another 20 lb/ft or so.

[madmax88]

in fore weeks I am going to remap the ECU !25 hp sounds good,I also just put some nice pipes on my j30 hope that means more hp aswell.