HowlerMonkey

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.

Shouldn't have mentioned it since it is tons more involved but it really is the future..........just too soon to be affordable or doable at this time.

I'm not sure the ecu cares whether resistors are on the positive or the negative side of the injectors since they are only there to limit current as seen by the drivers in the ecu. Care has to be taken if you're using any of the factory harness since many gang both the positive and negative sides of individual injectors together.

Stock 1981 280zx turbo resistor uses 7 terminals. One supply and the six individual resisted outputs. Dropping resistors can be wired in anywhere between feed to the injectors.

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.

Pull the valve cover and check if something up top is not allowing a valve to close fully. It might just be somebody who did a horrible valve adjustment.......though if it were driven a long time, the open valve might have burnt.

Stratified charge is multiple spark. Some direct injection schemes use multiple spray events.......I know.......I don't need to google it because I am a direct injection certified Lexus Technician. Direct injection atomizes the fuel to an unbelievable degree using up to 2000psi.......much better than injecting it against the back of a closed intake valve at 43psi pressure. Turbulence has been used mainly to hold relatively large fuel droplets as delivered by 43psi injectors to hold the fuel in suspension. With high pressure direct injection, this isn't an issue and that is why they can run super lean air/fuel ratios and high compression ratios up to 12 to 1 with regular unleaded gasoline. Now this is a nissan L6 forum and I doubt anybody is even thinking about direct injection since most here aren't pursuing anything past bank fired injection except in relatively recent Haltech, Electromotive setups..........so the grooves might be worth pursuing but I would combine it with a true sequential setup if I spent the time to machine the head.

If you go direct injection, would turbulence be needed? I always figured turbulence was to better atomize fuel that was in too large droplets. Direct injection allows lexus to run 11.8 to 1 compression ratio in their direct injection V6.

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.

What does your turbo drain look like inside?

I had a rash of quick lube come-backs at a lexus dealership and found the oil way high. It seems the quick lube guys would replace the filter and walk over to another car since we had an abundance of lifts. Then they would return and lower the car to fill it........but they forgot to drain the oil. Lots of smoke.

If the return hose is swelling, then the restriction is either in the hose itself or after it.

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.

Since he's getting the 2 or 3 second prime, I would assume he's using the L28et engine management system. If so, the ecu sends a negative out to a fuel pump relay on the blue with red stripe wire which you can find on a six way connector. After the prime/starter running/ the ecu won't send out the negative to energize the fuel pump relay until it sees a good crank angle sensor/distributor signal. The positive output from the fuel pump relay goes out also to the warm-up regulator on the green wire of the same relay. Depending on the year, some 280zx turbos use a fuel pump speed controller which is on the body harness rather than the efi harness. I believe it acts on the negative side providing a couple of levels of grounding resistence. You can probably go around it and might have already done so if the negative to your fuel pump is grounded to the body.

I believe that honda is an interference engine and might have bent some valves.....depending on the model. Also.......the various front engine seals under the cover have a tendancy to just fall out so you might want to replace them as well.

I think the bolts are the same as the ones used on the water cooling for Z31 turbos. If so, then you have another choice on the metal lines from said turbo which you can swage oil lines to. Might be wrong but I think I just did this last year.

On 280zx, I always use the front crossmember and the rear diff.........unless I have a flat tire on the side of the road. Since the 50 buck jack that most people buy doesn't fit under the front, I usually drive the car onto two small 2x4 blocks. If I have to jack on the pinch welds (stock points) I am careful to use a wooden block turned 45 degrees and don't lift it high enough to cause the jack to try to pull which will could cause the dreaded fold over of the jack points. I worked at the Z shop of miami so long ago that my bay had no lift. I had to jack up every car and put it on jack stands to work on it. After that experience, everything now is a cakewalk.

Is the distributor and cap and rotor new? I've seen carbon tracking do some really wierd stuff.

Understand totally...........Z cars aren't the only cars many of us use our brains on. It might be a tight halfshaft u-joint.

I prefer good gameplay and realistic physics to graphics candy anyway. That's why the Wii grabbed so much market share on units with superior graphics horsepower. That said, it's hard to beat Grand Prix II or Grand Prix Legends (viper racing is the same as GPL) for realistic driving but there are newer games in GTLand GTR which have better graphics and sweet multiplayer options. If you like good gameplay and airplanes, I recommend Warbirds Freehost which is ...........well..........free because some russian developers got ahold of the code and are now hosting arenas full of people itching to shoot you down in a WWII plane. It's run on an older version but that's the only price you pay since it is free. If you think you will take off in a mustang and own, you are sadly mistaken as the mustang is only the top performer at super high altitudes and speeds and you just don't find many opponents who want to spend 15 minutes to climb that high. Come on over and receive some pepperidge if you dare. You do need a stick to fly and I recommend a "twisty stick" because the twisting is for rudder action. A good entry level stick was the top gun fox pro but it seems to have been discontinued but.......the more generic thrustmaster "usb joystick" looks much like it and probably costs less. It takes a bit of installation mojo and learning curve but I'm still playing it 10 years later while Grand Theft Auto and all the other Xbox games sit collecting dust.

Clearly, I need something better than the cheapy harbor freight auto darkening helmet. On using it, I have found out a few things. It works as advertised but it goes so unbelievably dark that I can hardly see my work. This is at the lightest setting while full on dark would probably protect one from a nuke detonated only blocks away. Does anybody have experience with a different brand that has a better range of "darkening" that is actually useful? One more thing.........don't use an auto darkening helmet outside at night. I stuck my first "night arc" with this helmet and got a big strobe effect before the auto darkening clamped down. I then tested this by pointing a light at the solar cell to keep it live and got no strobe effect. I believe this is because it is powered by a solar cell so...........if you don't have ambient light powering the unit, you get a delay in darkening since the unit is not actually "live" in the dark...........apparently the circuitry doesn't include a capacitor/condensor or battery like device to keep it live in the lull between arcs. Just a heads up that will save your vision if you weld in a dark area that might not have enough ambient light to keep the unit responsive. I'm sure taking it apart and using a battery rather than the solar option would stop this but I'm done with this helmet anyway because of the "too dark" experience.

Pinion angles changes with ride height? Doubt that but halfshaft angle will.

If you see the tach twitch, then the coil is not being fired at that time. I would guess it's the black module on the distributor. Sometimes you can wiggle the connector and influence the intermittent problem to occur as well as tapping near it on the housing of the distributor with a brass drift.

1987 300zx non-turbos manuals have 3.9 as do some 200sx turbos though some have 4.1

Mercruiser is a inboard/outboard maker. Mercury is the outboard division. There have been some good innovations in 4 stroke outboards lately. Supercharged inline six of 275hp.