late Pathfinder or Quest OBDII ecus on L eng?

[HowlerMonkey]

This looks promising.

 

 

It seems the crank angle sensor is only there for diagnostics and not the general running of the vehicle.

 

It also seems it does use the flywheel/flexplate teeth of which the count is 120 teeth.

 

The L28 also has 120 teeth!!

 

This means it shouldn't be too hard to implement this using ecus from any late single cam vg30 or vg33 (at least up to year 2002) and get the benefit of all the sweet diagnostics capabilities as well sequential fuel injection and the aforementioned ability to update the run time calibration file from the data link connector.

 

Of course, you will need to run dropping resistors since the ecus expect high impedence injectors.

 

I'm still working on the M30 sequential ecu with this engine but I may abandon that and go this route sooner than later.

[woldson]

OOOOOOoooooo, cool!

[Bernardd]

 

This means it shouldn't be too hard to implement this using ecus from any late single cam vg30 or vg33 (at least up to year 2002) and get the benefit of all the sweet diagnostics capabilities as well sequential fuel injection and the aforementioned ability to update the run time calibration file from the data link connector.

 

Of course, you will need to run dropping resistors since the ecus expect high impedence injectors.

 

I'm still working on the M30 sequential ecu with this engine but I may abandon that and go this route sooner than later.

 

Do you have a link to the tuning software? I know where to find the equipment to reflash the ecu but I cannot find anything for actually tuning tables and such.

[HowlerMonkey]

I'm sure any of the many software packages that allows editing of the Z31 and others binaries will do.

 

You might get away easy with just finding the VG33er (supercharged) calibration file and flashing it to any of that ecu family if you run stock boost.

 

It's a good starting point.

[Bernardd]

I can say with great certainty that none of the obd0-I software will tune or edit or flash obd II ecu's.

What is it a good starting point for? What is the goal? Sorry if I missed you stating what it was.

[eec564]

The software isn't for OBD of any sort. You dump the rom from the chip in the ECU, edit it, flash-it (having to solder in a re-writeable chip) and go. Live Edit may very well work, I just don't know if the ECU's CPU is similar enough (or the same) as to have the same memory locations for tables and variables.

 

It's easy to find Nissan Live Edit. Get a copy and play around with it.

[HowlerMonkey]

Holy crap........tired of restating what has already been said multiple times in this thread.

 

This thread is like watching history channels "dogfights" where they feel the need to recap the entire show after each advertisement.

 

The "good starting point" is that a VG33er (supercharged ecu) uses the same signalling as the Z31 ecu, has the turbo injectors, offers sequential injection, and is flash updatable by a shitload of scantools and programmers.

 

Using the fact that these OBDII ecus both supercharged and non-supercharged have the same injector sizes as the Z31 and L28et ecu, then it's easy to use a hex editor search function on the known values and you can divine where they exist.......if they even are in a different location........they might be in the same area.

 

You know I've been doing exactly this kind of stuff for a living for the last 3 years by writing test profiles for signal generators contained within the ecu testers with which I test thousands of ecus a year by testing every single bit of functionality that most any mainstream ecu offers.

 

If you've ever bought an ecu from Carquest, pep boys, and thousands of other car parts chains in north america, chances are that you bought one I tested/repaired.......or wrote the programming that allows us to test them.

[Bernardd]

I wasn't clear enough in my question. I have no interest in your qualifications, past experiences or job references. My question is: what is the point in doing all this work, when you can tune your car with a fully hacked oem ecu that you pick up in jy for a few bucks and nistune or similar. You can control injector size, injector phasing, fuel over several maps, use any voltage base maf you want, convert it to map if you want, sequential injections, run coil on plug, single coil, wasted spark, dwell control (rpm and timing based), control a water injection pump, control boost, decel timing, fuel cut, over boost control, hot startup enrich, cold startup enrich, start up timing and more that I can't remember off the top of my head. The consult port provides info on all the sensors, which can be datalogged. I started playing with nissan ecu's in 1999 and I have looked at nissan obd II code and it looks completely different to any of the currently hacked code. You will be able to find the timing, fuel and perhaps the maf tables easily by looking at the hex editor but no software will help you find the constants. That is why I ask if there is some hidden benefit making this worthwhile assuming you already know what's out there for nissan ecu's and what can done with them.

[Xnke]

Seeing as he has worked with the ECU's for a long time, I'm sure he can find the constants and variables needed. it's not that hard, if you know how to look at code.

 

The benefits are many:

 

cheap ECU's

modern sequential injection

STILL TUNABLE

OEM look, for those who need it

I'm sure there are more

 

In the end, he wants to do it. biggest thing i see is better milage and a nearly drop in swap. Zcars are not at all common near me, but pathfinders and quest vans are everywhere.

[GrayZee]

1. There is a Nissan/Infiniti M30 ecu on ebay right now for $89 buy it now, including shipping.

 

2. M30 ecu's use sequential injection.

 

3. It is very tunable.

 

4. It has the OEM look (although more modern style than anything a L28 would have had)

 

5. Gas mileage is based on AFR's and O2 feedback, which can also be tuned in with the M30

 

6. Best of all, it uses the stock L28et/Vg30 crank sensor as long as a Vg30 disk is installed.

[Xnke]

Which makes it sound very similar to the ECU's that Howlermonkey is trying to get working. More is better when it comes to choices, especially since M30 ECUs may not be easy to find forever. But, for me I'll wait and see. No dizzy on my engine, so no sequential for me this way.

[HowlerMonkey]

My question is: what is the point in doing all this work, when you can tune your car with a fully hacked oem ecu that you pick up in jy for a few bucks and nistune or similar. You can control injector size, injector phasing, fuel over several maps, use any voltage base maf you want, convert it to map if you want, sequential injections, run coil on plug, single coil, wasted spark, dwell control (rpm and timing based), control a water injection pump, control boost, decel timing, fuel cut, over boost control, hot startup enrich, cold startup enrich, start up timing and more that I can't remember off the top of my head.

 

Which oem nissan ecus have sequential injection on an engine that doesn't have variable valve timing or requires a 180 tooth crank angle sensor?

 

The answer is the M30 ecu and the quest/frontier/xterra/villager ecu.

 

The quest/frontier/xterra/villager obdII ecus litter the junkyards of america and require the exact signals that the factory L28et engine sensors already output.

 

My goal is to pass emissions in a 1991 car with a L28et in it, get better efficiency with sequential injection and be able to flash a new calibration to it with anything from a Blue streak global programmer or Iflash unit to the good old Vetronix mts3100 scan tool.

[Bernardd]

I see. Can you download the binfile using your equipment? Send one over.

[HowlerMonkey]

I recently got released/fired.

 

I have interviews this week with the competition as it seems my area has a few companies like this.

 

I could end up a nissan, infiniti, toyota, or lexus technician by the end of the week which would gain me access to what's needed but working in a very hot shop is something I promisied myself I would never do again.

[Daeron]

.....but working in a very hot shop is something I promisied myself I would never do again.

 

Nancy boy. REAL Floridians don't break a sweat until two minutes before it starts raining at 95 degrees.

[HowlerMonkey]

I'm temporarily stopping research on this for a short while since I need to concentrate on making money.

 

I've been tapped to be the japanese tuner at a performance shop but I have huge gaps in my knowledge considering running a dyno so I may end recruiting talent instead of doing the job......not sure yet.

 

If you're local to West Palm Beach and are a japanese specific tuner with dyno experience, you might find the facility to your liking.

 

PM me here or send e.mail if you can fill the job.

 

princemakaha@yahoo.com

 

The dyno has 2000hp capability.

 

I'm helping out putting together sensors for a 6 stage boost controller so he can have different boost limits for each gear selected since his car puts down a bit north of 1500hp.

 

Apparently the time based system is lacking and tailored to drag racing so the boost controller will have to use the gear based function.

 

[HowlerMonkey]

I'll eventually get to the OBDII ecu research again but am currently studying the ecus from the PRE-OBDII cars but only ones equipped with a consult port.

 

The goal is to find a much more common ecu than the M30 ecu so we can reap the benefits of sequential injection and fuel trim on our "L engines" without trying to find an M30 ecu since they just didn't make very many.

 

Once the ecus capabilities are known, I will figure out the harnessing that is easiest to adapt to the "L engine" and which ones are most easily removed from the donor vehicle.

 

Currently, my L28et is running sweet on a unmodified M30 ecu driving stock 260cc turbo injectors through dropping resistors and it seems the M30 ecu is sophisticated enough to "pull fuel" on the 90cc/min larger injectors without going crazy rich.

[woldson]

Funny, I was just thinking of this thread just a bit ago.

 

Great job, looking forward to your progress;)

[jeffp]

I have been reading this again, and one thing sticks out for me.

The spark, which was one of the reasons I dumped the Z31 ECU. I had too much duty cycle at idle, and I was a little shy on the high rpm side. The SINGLE coil setup was not a good fit to the high RPM's and effective spark to begin with, and I can tell you I tried all of the adjustments that were available in the Z31 unit, and also the M30 unit. THE SNGLE COIL setup is not good enough for high boosted over 500hp applications.

EXAMPLE: The MSD 6A box, very popular, works very good until you get into the 20psi boost levels. What is the first thing people do to stop a misfire @ high boost levels??? THEY DECREASE THE PLUG GAP! This is done because there is not enough SPARK DURATION or duty cycle. There is NO way around it. I tested the msd box; they advertise 17 degrees of spark duration, which equates to 500 microseconds or .5 milli seconds of spark duration. The spark gets blown out with the fuel, temperature, air, and most importantly, the cylinder pressures developed with a high boosted engine, NO WAY AROUND IT! The spark is to short in duration to effectively ignite the air/fuel charge. The single coil systems, have to produce spark six times more then the coil on plug setups, and from my bench testing of the systems, the single coil setup, whichever system we are talking about has to start cutting back the duty cycle of the spark, or coil primary charge time, to get every plug to fire.

We are talking about effectively audio frequencies to the tune of about 45Hz according to my digital scope. I can see the charge time of the coil primary decrease on the scope as the rpm's increase. At the end of the day, regardless what I did to the ECU to make the spark duration longer at 7500 rpm's I was only able to get 900 micro seconds of charge time of the coil primary. As some of you may know, every coil has its specific coil charge time, and all of them are different. That is the reason for the various coils Nissan uses for specific applications in their cars, this is also true for fords and chevy cars. I tried 4 or 5 different coils, mallory, MSD, Nissan, Bosch, all of which I was not happy with the results, and in fact were not good enough to ignite my air/fuel charge at high hp.

Now the M30 unit is better in one respect to the Z31 unit. The M30 went a step further then the Z31 unit in that they realized there were some problems with the spark duration and made the M30 unit sequential injection, that solved the problems with the X31 box at high boost/duty cycle of the injectors. The injector problems were the first thing I encountered with the Z31 box when I surpassed the 500hp mark with my engine.

Due to the design of the Z31 box and hardware involved the ECU can only calculate the duty cycle to about 10 milliseconds of injector duty cycle. After that is surpassed and more injection time is required, the ECU then takes the current pulse to the injector, divides that by 50% and generates TWO pulses to get the desired TOTAL duty cycle for the injectors.

What this did was to create, ON THE HIGH END rpm, and power levels, right around 5K rpm's consistently, a very rich spot in the 10:1 AFR range, and then a lean spot up to redline. Ask Tony about this, it was clearly shown on the dyno graph. Tony and I worked on the rich/lean condition for a number of hours on the dyno, and we could not get rid of the rich/lean spot but simply move the spot to a slightly higher or lower rpm level. I was finished with the single coil setup after that $1000.00 dollar two dyno sessions, and Bernard was involved on the second session as well.

So the X31 ECU is perfectly fine for any L28 to 500hp maximum, and if you are using the MSD boxes you will never get consistent AFR's at that level with a boosted engine. I also dissected their box, had it backwards engineered, and when I found out HOW they were triggering the coil I stopped all work on mods for the MSD box. Not to get to technical, but what they do is charge a high voltage .1 microfarad cap, directly off of the step-up power transformer (450-550 volt output) and use the cap to set the spark duration which if you do the calculations of the cap charge time, plugging in the voltage, and power developed by the power transformer in the 6A box. The duration equates to 500 microseconds duration and that number can ONLY be changed with the output cap. Well that is not too hard to change, BUT with the longer duration what you get at 7K rpm's is the firing pulses fro each cylinder RUNNING INTO EACH OTHER, that basically KILLS the spark of the coil. Now that is a quick engineering evaluation of the single coil system. The other problem was with the power transistor, or igniter. The stock Nissan unit (on the 280zx car) pulls the 5 volt potential (or 5 volt square wave to the transistor base junction) to about 2.5 volts, chops the top of the square wave off at the rising edge of the wave and creates a waveform very similar to a saw tooth waveform riding on top of the 2.5 DC Volt potential. I designed a FET driver transistor setup that took car of that, and I thought I was out of the woods on the ECU ignition problem, but I was incorrect. I was able to get good spark duration at the high rpm levels, about .9 milliseconds to .85 milliseconds, and that was good enough, but when I brought the RPM's down to what would be an idle state for the car, the effective duty cycle of the transistor input, and output was to long. The duty cycle of the spark ended up at about 5 milliseconds to 8 milliseconds. Needless to say my coil got a little hot, so that was unacceptable as well. I started cooking coils, so that was another nail in the coffin for this box and application for my requirements. Single coil setups wll not be effective for high hp engines that are boosted period! Ever wonder WHY top fuel uses TWO distributors? I can tell you, having worked for Mallory electrc, the premier designer of magneto systems, the spark duration at high RPM's is not good enough to ignite the air/fuel mixtures. Hence, two distributors, and BTW clocked a number of degrees apart from each other to get the required spark to run the engine. My first guess would be 15-17 degrees apart.

NOW! the sequential Maxima, Z32 ECU:

I tested the units, and because they ARE FULLY sequential, (which was not the case with the redline webber ECU882 unless you have a cam trigger) you have a significant duration in triggers for the coils and the injectors. I ran the unit to 12K rpm's (and it loses its marbles at about 12,400 RPM's not to bad) and I still had slightly OVER 2 milliseconds between the pulses for the injectors. The coils measured about the same, plenty of time in-between pulses to fire the injectors, and fire the coils effectively. That is precisely WHY I went to the sequential systems. You can try to get more out of the single coil/single injection systems, but at the end of the duty, ALL ECU's will operate the same in perspective of the single coil systems, and that aint good enough for high hp and boosted engines.

 

The OBD2 systems were designed for EMISSIONS NOT PERFORMANCE! So if you want to run the system go for it. The harnessing is a pain in the butt, I have built two harnesses, one for the redline system, and a second for the Z32/Maxima, what I call the big blue ECU connectors, and that ended costing me about $400.00 for the Nissan unit. The connector terminals for the connector, well lets say I got raped on the cost for them at bout $.75 each, and you can count the pins, 72 to be precise, then going to the junk yards for the connectors, sourcing the wires, and the biggest pain the butt was that I had to physically make my own crimp dye to crimp the stock Nissan terminals. Costly, but I am very pleased with the setup now and it fits my car exactly like the stock harness, all of the stock Nissan connectors, plug and play!

So if you want to run down that rabbit hole headlong, go for it, but I am telling you there are better Nissan boxes to use on your car, and DON'T forget NISTUNE, it has full tuning capabilities for every aspect of the car, and is capable of triggering, anything you would want to trigger like stock waste gates, second fuel pump if needed, idle control from software, EGR if you want it.

The O2 challenge for the Z32 box is that there are two units, but I have to do a little more research, but I believe I can use a single sensor (zirconia voltage scale sensor) and input that into a voltage input dual output digital pot (resistance out isolated but equivalent resistance output, or parallel output that is isolated) to input to the ECU, now how about that option.

The second is the Maxima 92-94 ECU that uses the single sensor (and BTW, the connector and pin out for the Z32 box, LESS the second O2 sensor input) is identical, plug and play after you have the harness. The one thing I did not like was the volumetric efficiency table. This table is part of the main fuel map, BUT it only operates up to 3200 rpm's then the primary map takes over. I did not care for this table at first, but after working on the Z32 box, I think I am going to reinvestigate this box and see if I can get a little better resolution for the drivability of the car to 3200 rpms, which just happens to be the point that my turbo threshold is give or take 200 rpm's I wont tell one way or the other, as that is another debate, boost threshold, of which most of you in my opinion require to high of rpm's to reach, but again that is another debate.

So there you have it, everything I was able to test and verify on the Nissan boxes. I really don't need to investigate any further, as these units will do everything I want them to do, fuel the car, and provide sufficient spark.

[Daeron]

WOW that was a lot to digest.... Thank you for your input, this is a thread I plan on re-reading in the future and it seems like you just added about a metric sh!+load to it...

 

I am for some reason stuck with this preference for MAF based systems, and I have no rational justification for it (whatever justifications MAF versus MAP have, I have no personal experience to make any argument worth dingo's kidneys) but that has been the reason I have kept this idea in mind... and you point at the Maxima that had twin butterfly TB's, which touches on another idea I have had...

 

so like I said, thanks!!