late Pathfinder or Quest OBDII ecus on L eng?

[HowlerMonkey]

It was more wishfull thinking on the flywheel teeth since 120 is 1/3 of 360 which could make sense since a three pole sensor would yield 360 peaks per revolution.........which I hope isn't the case.

 

Best case scenario is 180 teeth on the a tone wheel meaning I can use the stock 1981 280zx turbo crank angle sensor and a 1982/1983 distributor and the OBD2 ecu would be satisfied.

 

I haven't been in one yet to look and there is very little information on the net other than some maxima flywheels that have a tone wheel much like jeep but it is a different engine family than the VG30 or VG33 single cam engine.

 

I troubleshooted many jeeps a week and always find either the cam, crank, or vehicle speed sensor on the 8v circuit (depends on year) to have shorted reference voltage to ground or.........starter ring gear teeth particles have stuck to the sensor.

 

I don't want to spend the time removing the tranny from a quest just to look but maybe I can find one separated already at the wrecking yard tomorrow.

[Pharaohabq]

Okay, so you're going to use an ECU+ wiring from a Quest, right? So pretty much we need to see the timing signals from a Quest to figure out what you'll need from the CPS and CAS. Both being 6 cyl engines, it stands to reason we should be able to work it out. Basically duplicating the signals from each. If you go a little newer you can use NDIS and do away with the distributor. It would then be fully timed off from the CPS. The difference beteen a V6 and an I6 is negligable in that the cylinders all fire in an order once per rotation. so you'd need to verify the firing order on the Quest and swap cylinders for the order in the L28. The VSS will be harder to figure, though you may be able to swap it for a GM VSS. Timing off the CPS can be done by modifying or bolting a plate to the Harmonic dampener. You could also see if the dealer will run you off a couple pages on the Quest timing signals out of their Service manual. Separately you can DL the FSM for all the years of the Z cars and see what works there.

 

phar.

[HowlerMonkey]

Newer?.........the engine management system I want is for a 2002 quest.

 

Sadly........all of the distributorless ecus nissan makes for V6 expect variable valve timing.

 

The reason for my wanting this is that the 2002 quest and the other obd2 ecus for quest/villager, and some pathfinders are for a non-variable valve timing engine.

 

I don't need to bolt a plate to the harmonic balancer because I already have one and a crank angle sensor that way because they come stock on a 1981 280zx turbo.

 

The wheel has 90 teeth but has two pole pieces in the sensor netting 180 pulses per rotation.

 

The caveat is that, much like the 280zx turbo distributor optical disc versus the 300zx disc is that cylinder 1 or the 280zx turbo crank angle sensor wheel has the same 60 degree waveform for all cylinders while the 1984 Z31 through the 2002 pathfinder require cylinder 1 to have a wider pulse width (might be a gap).

 

All I need to do is see if the tone wheel on a quest doesn't have a gap or a wider width tip for cylinder 1 identification.

 

Sadly........all newer ecus expect a cylinder 1 ID pulse to be different from the other 60 degree pulses.

[Pharaohabq]

Hmm okay, But doesn't the earlier Maxima's say 2002 or 2003 not use VVT? I'd heard that, since I know people swap maxima heads to their VQ30's so they don't have to deal w/ VVT, though I don't know of those are distributorless or not. If the VVT isn't connected, will the ECU throw a CEL? Maybe we should look at how the maxima guys get around that.

 

If you're planning on using the CAS and CPS on an 81 L28, then you'll need to figure how best to make it match the Quest flywheel. Have you looked up the flywheel online to try to find a picture? I know my Vq35 flywheel has a completely different timing pattern. have you compared the boltparrtens and size of the Quest flywheel and the L28et? if it could be made to fit, it would solve a lot of issues.

[HowlerMonkey]

Looked everywhere........hours of research and no pics of the quest tone wheel.

 

The big "IF" is the quest flywheel or tone wheel.

 

It seems the only way I will see one is to take one apart at the junkyard myself.

 

The reason for the quest and some pathfinders is that they are OBD2 but single cam engines without VVT.

[Unclejesse]

as quoted from the 02 villager pced: The camshaft position (CMP) sensor (Figure 1) is mounted inside the distributor housing. The CMP sensor has a rotor plate and a wave-forming circuit. The rotor plate has 360 slits for 1 degree signals and 6 slits for 120 degree signals. When the rotor plate passes between the light emitting diodes (LEDs) and the photo diode built into the wave-forming circuit, an input signal is generated and sent to the powertrain control module (PCM). This signal notifies the PCM of the engine speed at 1 degree intervals and the crankshaft position at 120 degree intervals.

 

I also have a picture of the distributor tone wheel, I just need to figure out how to post it

[Unclejesse]

lets see if this works

[Pharaohabq]

ick! thanks uncle jesse for the picts. Tell the duke boys hi for me and especially daisy.... working with the CAS on a 360 degree deal like that really looks like it'd be a pain to adapt to an L engine. what does the CAS signalling look like in a L28ET engine? I doubt we'd be able to adapt the Quest Cas distributor to the L28. very easilly...

 

yeah looking at the tone wheel from a quest would answer a lot of questions, I looked too n couldn't fine a frywheel picture. maybe we can get the dealer fo fax us a page on it

 

Phar

[Unclejesse]

that text I posted would lead me to believe that the pcm gets cam and crank position both from the distributor. So I don't know why it would have crank position on the flywheel as well. Are you sure it wasn't just turbine shaft speed for the transmission?

[HowlerMonkey]

This (pictured) is listed as a mercury villager/nissan quest VG33e crank shaft position sensor.

 

Same part listed for frontiers, infiniti QX4, and pathfinders with single cam VG33 engines.

 

 

Here it is in the car.

 

 

Nissan painted themselves into a corner concerning terminology when they introduced the VG30 by calling the distributor a "crank angle sensor" because they later had a genuine "crank angle sensor".

 

I'm amazed I cannot find a single reference to the waveform or at the very least how many teeth there are on the tonewheel as well as gaps in teeth and such.

 

That is all I need to move forward.

 

This thread is moving backwards rather than forward so I'll get back to it once I figure it out rather than having to restate the facts with every successive post.

[Tony D]

From what I've seen the waveforms are identical regardless of the signalling medium.

The square wave off the optical CAS is the same as the shaped waveform off the magnetic pickup CAS on the front of the engine.

 

It's not critical, really, it's a trailing or leading edge trigger and most functions work on trigger return anyway.

 

Gaps are not as important as how many are there. You can make the EXACT same waveform off a flywheel with 2" thick raised nubs as you do with an optical setup running 2" diameter and laser cut slots.

 

Curiously, as speed increases the larger flywheel sensors tend to be more accurate due to the resolution.

 

using the small chopper wheel in the distributor just wasn't reliable above 8500 rpm in our TEC2 Bonneville car, while the larger wheel on the pulley worked well above 9500...

[HowlerMonkey]

Sweet.

 

I may give the ecu what it wants off of the 1981 wheel and sensor but I was hoping for something that didn't require such a hard to find part.

 

If the ecu expects the crank angle sensor waveform that is the same as the one provided by the distributor, then it should be easy.

 

I still want to see the wheel that the quest/pathfinder/qx4/frontier/villager....etc. has

 

I guess obd2 certifictation requires long intervals between service that would make a belt driven reference not as accurate and I think obd2 requres phase checking between cam and crank sensor for diagnostics since you can tell from the live data whether there is discrepancy between the two signals.

 

Really what I want is something everybody can use to get good performance, good emissions, and flashability from the connector.

[Tony D]

A lathe, indexing head, and milling attachment with a very small mill is your friend in this endeavour! If you choose to make your own, and fit it to a distributor housing, that is!

[jeffp]

If you want to run a quest ECU, and I really don't know why you would want to, but get the CAS and chopper wheel from the Quest.

You can drive the CAS like it is driven on the 280ZXT. I have a Z32 and a VE30DE cas and they are identical, same chopper wheel which is nice as getting the wheel from the VG32 Z32 is a pain in the butt and poses a number of mechanical problems. The VE distributor is the best to start with, you get the CAS, chopper wheel, and the spacers and mounting stuff to install into the zx distributor.

So chances are, that if you have a 6 cylinder with independant coils on the Quest, I would be willing to bet they trigger the exact same way.

The Z31 triggers differently then the VE or VG Z32 fuel management systems. The Z31 has a watch dog timer that is triggered by the bigger slot to reset the timer. The fully sequential systems have an all together different setup. The first slit is about 1.3mm wide and the last slit is about 6mm wide. The slits increase as the engine fires each cylinder, and you start the counting all over again.

The single O2 is most convienent, the VeE maxima has one sensor. The Z32 has two sensors, but I have gotten a circuit that will drive both inputs to the box from the single O2 output. Problems solved.

The hard part is wiring in all of the sensors, but once that is done it's all down hill. Then all you need to do is tune it LOL, all you got to do.

[HowlerMonkey]

The quest ecu is sequential, it requires no extra coils, it is fully OBD2 compliant, it runs with a single coil, it expects the same distributor waveform as delivered by any VG30 or VG33 single cam engine from 1984 to 2002, and you can flash it with a new bin file through the OBD2 port.

 

The only "work" needed to run this is putting in three 02 sensors and supplying it the crank angle waveform it expects.

 

To do this, all I need to do is actually see the tone wheel so I can duplicate the signal it creates and the rest is easy though some fancy placement of the 02 sensors in a single log manifold might be needed to satisfy the "two bank" scheme.

[Xnke]

All this work is great, but i think either Howlermonkey is missing the point of Unclejesse's post, or he understands and i am just missing it: the '02 villager 'distributor' wheel, from the picture, LOOKS very similar to the '82/'83 ZX 'distributor' wheel. If they are not identical marking wise, are they able to be swapped out mechanically? still doesn't sort out the crank angle sensor, but it does provide an easy method of getting the cam sensor sorted out.

[Unclejesse]

There is only one dtc available in the pcm for the crankshaft position sensor. Quickly following it they have you inspect the flywheel for damaged teeth. This would lead me to believe that you are right about the ckp reading flywheel teeth. BUT, I cannot see how this can be for crankshaft position, and instead be purely crankshaft speed. The flywheel teeth would need to have some sort of indexing tooth, yet still be able to be run from the starter.

[HowlerMonkey]

All this work is great, but i think either Howlermonkey is missing the point of Unclejesse's post, or he understands and i am just missing it: the '02 villager 'distributor' wheel, from the picture, LOOKS very similar to the '82/'83 ZX 'distributor' wheel. If they are not identical marking wise, are they able to be swapped out mechanically? still doesn't sort out the crank angle sensor, but it does provide an easy method of getting the cam sensor sorted out.

 

 

Sure the 280zx distributor optical wheel is different than the 300zx wheel but the 300zx wheel is the same as the quest wheel..........I've compared both and have run a z31 system on the L28 as early as 1989.

 

It's just a matter of time before I find a quest/villager/pathfinder/qx4/frontier that is apart so I can see the tone wheel...............that and a real job so I can stop rolling up my change.

 

In my 3 cars, I have found 160.00 worth of change in the last week.

 

If nissan/infiniti hires me either as a tech or service writer, then this will move really quickly.

[Pharaohabq]

Here's to hoping you get hired. In the meantime can you call the dealership and see if they have a Quest tonewheel/flywheel availiable in stock? maybe napa? I don't expect they burn clutches very often. so probably it would have to be ordered.

 

If you ran the Z31 system on an L28, and the Z31 is similar to the quest, wouldn't it stand to reason that the quest system should run on a L28 pretty easilly.

 

Oh and I highly doubt anything reads the ring gear on the flywheel, they have you inspect the teeth since they're easilly damaged if you drop the wheel, and you don't want to install a flywheel with bad teeth, since you'll end up pulling it again in short order. that's the only reason is says to inspect.

 

Phar

[Unclejesse]

The inspection of the flywheel is called for in a pinpoint test to diagnose a bad crank sensor. The ppt nowhere tells you to inspect the tone wheel/reluctor. It is possible to use gears for speed sensor tone wheels. I went to a trans class for ford just last week where they used the teeth on the spur gear to get output shaft speed. I mean, a gear is basically the same shape as most tone wheels.