New MS3 install for my L28ET

[SleeperZ]

It's the same radiator and fan I ran last June, a Champion aluminum unit for the 280Z and a pair of shrouded 11" fans from SummitRacing.com.

 

http://www.summitracing.com/parts/SUM-G4852/?rtype=1

[SleeperZ]

Spent the last two weeks taking care of wiring and other details, like programming the maps into my laptop and verifying the sensors. Got a tach at cranking speed, so I installed the injector fuses and tried firing it up today.

 

Actually fired right away, but couldn't get it to idle it's running so roughly. Looks like I'm missing spark on #5, and it's not the wire (swapped wires with #3). The plug is gapped and seems ok, so perhaps it's as simple as a bad distributor cap.

 

If Megasquirt was pulling the spark because of a bad tach signal, I assume it would find a way to tell me, or would I have to make a datalog and check it? I am using a Z31 wheel in my '82 L28ET distributor, so one of the pulses is wider than the other 5. I did change the tach input from falling edge to rising edge and it made no difference -- cylinder 5 still dead.

 

One other issue. I have a fuel leak on one end of my Pallnet fuel rail. Looks like the 3/8 NPTF tapered threads are cut too deeply and my 3/8 to 1/4 NPT reducer may be bottoming out. I replaced the bushing and got it as tight as I could without tearing anything up, but it still has a slight leak. maybe I'll replace my reducer with a pipe, and change the rest of the hardware to fit my 1/4 NPT to AN -6 fuel line connector.

 

Won't be long now, but I hate these little annoyances....

[Noddle]

One other issue. I have a fuel leak on one end of my Pallnet fuel rail. Looks like the 3/8 NPTF tapered threads are cut too deeply and my 3/8 to 1/4 NPT reducer may be bottoming out. I replaced the bushing and got it as tight as I could without tearing anything up, but it still has a slight leak. maybe I'll replace my reducer with a pipe, and change the rest of the hardware to fit my 1/4 NPT to AN -6 fuel line connector.

 

I also had a leak with my Pallnet fuel rain and thread tape did not fix it, in the end I used a liquid thread sealer,

it worked a charm

 

Nigel

[SleeperZ]

I'd hate to rely on thread sealer, the yellow teflon tape has always worked for me. I had this issue with the return end of the rail, and a new reducer bushing fixed that end. I think I will either install a pipe nipple and adapt the male thread to my AN fitting, or get a bushing without the hex end. Either should seat deeper into the rail.

 

With regard to the miss I am convincing myself it is MegaSquirt.

 

The firing order for the engine is 1-5-3-6-2-4. It's number 5 that is totally missing (no flashes from the light), which is after cylinder 1 that has the wider slot in the Z31 6 slot distributor wheel.

 

I am thinking somehow a wider slot in the basic trigger input cause the next cylinder to not fire? Basic trigger may assume the slots need to be the same width, and when the edge is delayed, it cancels the firing event? I did try both rising and falling edge in the trigger setup, so I still have doubt.

[Matt Cramer]

Could you post two tooth logs, one with each ignition input capture setting?

 

It is possible to use this disc for Basic Trigger mode if you have the correct trigger edge specified.

[SleeperZ]

Could you post two tooth logs, one with each ignition input capture setting?

 

It is possible to use this disc for Basic Trigger mode if you have the correct trigger edge specified.

I posted it in this thread on MsExtra forums, I can't upload it here.

http://www.msextra.com/forums/viewtopic.php?f=131&t=45333&sid=b94092706aebec390ce5adea6fc0bbd7

 

This is just the falling edge trigger (I can get the other one tonight), but you can see there is one "tall" one I assume is cylinder 1, followed by a short one (cylinder 5). I am presuming if I capture the rising edge trigger this should make all of them the same? Is that what is required for MS to time the ignition events equally for all cylinders?

 

If the opposite edge does not do it, I suppose I should just get the DIY wheel and be done with this BS?

Edited May 30, 2012 by SleeperZ

[Zmanco]

If you're going to change how it triggers, you might want to go EDIS. Timing is rock solid compared to old distributors. Derek has a nice kit too.

 

The only downside I've found is you can't use spark cut alone for rev limit or boost control since the EDIS controller goes into limp home mode and defaults to 10 deg advance.

 

Edit: Scratch that: just remembered you don't need EDIS with MS3, but you might want to consider using Derek's kit for the wheel and sensor on the crank damper.

Edited May 30, 2012 by Zmanco

[SleeperZ]

I'm comitted to the distributor at this point. The DIY wheel is a good option, guaranteed to work if the Z31 will not. This may not be my issue, it is possible I have a bad cap.

[SleeperZ]

Changed the tach input to opto, based on recommendation from MSExtra forums. The build instructions clearly sayy to use the VR input for nearly all tach inputs, but now I've changed it I have all my sparks.

 

Timing is way off, 20 degrees advance indicated in TunerStudio is more like 40 degrees. I've run out of room turning the distributor. Calibrating the timing is not intuitive, and I've seen no instructions. The distributor gear has not changed since I ran it last with the old fuel management, and the advance was fine with that, so retarding a tooth does not seem like a viable solution.

 

Tomorrow's another day.

[Zmanco]

Not sure why you're seeing the extra 20 deg from changing the wheel, but TS gives you a tool to deal with this. Go to Tools\Trigger Wizard. With the engine idling measure the timing with a light and then change the Ignition Offset Angle in TS so that the indicated and measured advance are the same.

[Matt Cramer]

I'm comitted to the distributor at this point. The DIY wheel is a good option, guaranteed to work if the Z31 will not. This may not be my issue, it is possible I have a bad cap.

 

If there is one cylinder not firing because the spark can't physically get there, it will show up as a longer tooth in the tooth log because the engine is slowing down. This may very well be the issue.

[SleeperZ]

If there is one cylinder not firing because the spark can't physically get there, it will show up as a longer tooth in the tooth log because the engine is slowing down. This may very well be the issue.

I have updated my thread on the MSExtra forums and posted a tooth log. I don't really understand why all the instruction on tach input says use the VR input, but tribal knowledge is the opposite. From what I can see, all the edge triggers are happening at regular intervals, so I assume the edge is properly set up and the 6 wheel slots are being read at equal intervals. The waves in the tooth log are me trying to keep up the rpm with the throttle because it won't idle yet, there is too much spark advance.

 

I appreciate any additional insight (thanks Dan for the suggestion on TunerStudio, I will try that tonight and see if I can get this beast idling properly).

[SleeperZ]

Figured out the tach reference, but MS is still dropping sparks, this time on cylinder 3. And my error in setting up the VR input was pointed out on MSExtra forums -- I did not re-adjust the trigger level via R56.

 

So today I rewired back to the VR input with the R56 set properly, and no difference. As far as I can tell, the Z31 wheel is a stupid design -- the wide slot is centered on cylinder 1, not edge aligned. I've wasted enough time with it, it's time to go with what's proven to work, so I am ordering the DIY 12-1 distributor wheel.

[Sam280Z]

Sleeper,

I've attached a photo of the 300zx wheel on top of the 280zxt wheel so you can see how the slots line up. The 300zx slot is not supposed to be centered - as it is not in the photo:

 

Regardless, using the wheel as trigger only will just affect when the coil fires, not if it fires or not.

 

I like the DIY trigger wheel better than the stock wheel because it gives better timing resolution, but it may not solve your miss problem.

 

Some things to check (I learned most of these the hard way).

1- Make sure you have resistor plugs and wires. I'd even ohm out a plug to be certain.

2- Route the trigger signal wire away from the plugs and wires.

3- make sure your grounds are all run back to a single point.

 

Sam

[SleeperZ]

I can see that the Z31 wheel SHOULD give proper timing on the leading edge. Perhaps there is an error in the MS firmware, because when I set my trigger edge in TunerStudio, the trigger log looks the same no matter which edge I use. I get one tall one (the wide slot) followed by one short one.

 

I am so sick of f-ing with this, if the DIY wheel does not work either, I am going to be really pi$$ed.

 

I have checked all of the wires and plugs. Yes they are all resistor type (measured), factory NGK plugs I've never had any trouble with, and the wires are in good shape. I've had bad wires before, and I have invested in GOOD wires. I have wired MS as good as possible. The coil trigger is no where near the high voltage stuff, and the grounds are all together, heavy gauge, and tied right at the engine where the battery ground is attached. I think anyone would be impressed with the wiring - I will show it if I ever get this pig out to the track, I have 4 weeks to get this straight.

[SleeperZ]

Made a little bit of progress, but it's getting a bit ridiculous. New cap, rotor and plugs, my fuel system is still leak-free, and I've got my ignition timing close.

 

The nagging issues I have are an intermittent ignition miss (wet plugs on 3 and 6) and I cannot get this thing to idle, so I can lock in the ignition timing. If I simply crank, the coil does not fire cylinder 1 consistently enough, and cycling power for each timing adjustment just does not seem to do what I intend. I don't know why it's getting me so off the rails, it certainly should not be hard.

 

And I back the air bypass on my throttle body all the way out, but I cannot get this thing to idle. Maybe it has to do with the miss, as my A/F ratio is hovering around 11:1 to 12:1, where it should be correcting to 13.5:1 for idle. But if I hold the throttle at 20% or so, it will idle somewhat smoothly. Not sure what I'm missing, but I understand adjusting the butterfly is not the correct way to get the idle - enough air should be able to bypass the closed throttle.

 

I have taken it around the block a few times, and it works alright, get boost, not too sluggish so the timing is close, and my BOV needs adjustment as I get a nasty bark from the turbo on throttle lift even though I have only 5 psi boost. Must be the serious lack of vacuum from this "mystery cam" I bought....

 

Hmmm. I'll see if I can post a datalog over on MSEXTRA, maybe I'm simply running too rich and my plugs are fouling. I am using Zmanco's same fuel table, half the fuel (3.5mS) at twice the VE. Should work for my 440cc Supra injectors.

Edited July 4, 2012 by SleeperZ

[SleeperZ]

It's been far too long since I had time to work on this, but I FINALLY got to it Sunday. And what did I find when, out of frustration, ripped out the distributor and checked the wiring? An intermittent connection inside the black wire at the distributor end of the connector. Bastaaaad!

 

Gonna fire it up tonight, I replaced the wiring harness with 8" of individual wires with terminals into the distributor. I sure hope this is it, maybe I can put some time on this MS-III before the track day on Saturday!

[Zmanco]

Glad you found the culprit (we hope)! Do come out on Saturday - so far the weather is forecast to be relatively mild so should help keeping the cars (and drivers) cool.

[SleeperZ]

Tach input is good now, timing light solid, no missing.

 

I cannot get this thing to idle, despite opening up the air bypass on the Weber throttle body completely. I can hold the throttle at 20% and the engine is smooth at 1000 rpm. I don't get this, there should be plenty of air -- it idled fine with the old Z31 ECU.

 

I haven't got the timing set yet. With reference set to 345, I don't have enough distributor range to get to 20 degrees of advance at idle speed. 10 advanced is as good as it gets. Just add 10 degrees to the reference, correct?

 

While I was messing with it in the driveway tonight, I turned on the VE Analyze for a bit, and the ajdustments TS wants to do seem very excessive. I have adapted Zmanco's VE, advance and AFR settings to MS-III, along with doubling the VE table and halving the injector time. For some reason these settings are extremely rich, and TS wants to reduce my VE table by 40% or more. Something is not quite right in the way I have entered the tables.

 

And then my neighbor came out and asked me to shut my noise/smoke machine down. Fun's over.

 

Why can't I attach my .msq file?

Edited September 5, 2012 by SleeperZ

[Zmanco]

Sounds like you've slain another dragon and now need to fight the next one

 

Have you double checked the cam timing? Both symptoms (can't get enough air to idle and much too rich) sound like the cam is retarded.

 

As for being out of range with the distributor, if you're using the distributor only as the tach trigger, then yes, you can just add some more advance in MS. But if it's also distributing spark, then you may run out of range of overlap between the rotor and the nodes in the cap. I think you're going to have to drop the oil pump and move the shaft one tooth.

 

Sounds like you are getting close - slay these last dragons and bring her out to the track on Saturday - great chance to do some tuning