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New MS3 install for my L28ET


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NGK BPR7ES11, brand new

Beck-Arnley cap and rotor, brand new set

Running some custom 8mm Accel wires, never had trouble with them before, clean and flexible

Current have a MDS Blaster 2 coil wired, same inductance and resistance as the stock ZX coil, driving it with the MS coil driver


I wired the grounds to the same spot as the battery negative on the block, of course all sensor grounds are wired to MS.


Here's another straw to grasp -- I do not have the distributor wired to the body any more. There is no electrical connection from the optical pickup to ground, but there may be a charge buildup issue on the dizzy, and that's why the factory had that ground wire from the distributor to the left fender.

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  • 11 months later...

Good news!  It's been a year, and because Colorado changed the laws regarding '76 - '81 cars, I have to get emissions tested to keep my classic car license plate, and it expires at the end of September.  It sucks, but it is a kick in the rear for me to get this thing running.


I swapped the head back to factory, retimed everything, had my injectors cleaned and flow tested, and I actually got this beast to idle at 14:1 mixture and 950 rpm with no sync loss.  I checked the timing signal with an oscilloscope and it is actually fairly clean considering I am using the internal ignitor (BIP373) to drive my MSD coil.  Just a little bit of high frequency noise at the high pulses of the DIY 12:1 distributor wheel.


I still need to get it driving (my clutch master cylinder failed from lack of use) so I can tune it to drive and get it to emissions testing, but I think the big battle is won.

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Did some driving around last night, and it feels like I've upgraded to people-based relationships from my old "donkey" of a Z31 ECU.  My base maps I got from ZManCO are serving me well, Tunerstudio is making minor (less than 10%) changes to my VE tables, and it drives so nice without any idle control or acceleration enrichment programmed.


I have to tighten up my BOV as I can only manage 4-5 psi boost with the controller off, and I am going to do a little more work on getting the idle perfect (timing, mixtures).  I also snagged a charcoal canister for the tank evaporative system from the parts yard so I can pass the visual part of emissions testing.


Wish me luck, going to try emissions testing Wednesday.  It's running nicely, just keeping my fingers crossed.

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I'm still trying to get in for an emissions test.  I've driven the car a lot in the last few days, and the tune is starting to come together.  But I am wondering about my idle tuning, the mixture is not that solid although it may be good enough to pass.


Setup is:

MS3, no MS3X

L28ET F54/P90 head

DIY CAS wheel

Hyundai TPS, reports 2% at idle

7MGTE 440cc low Z injectors, batch fired in banks 1-3 and 4-6

GM air and coolant sensors

MSD Blaster 2 coil, driven with MS3 BIP373


I have it set in the AFC map to 14.0 - 14.2, and my timing is 18 degrees.  I set my coil to 3.0mS maximum dwell and 1.2mS maximum spark duration.  I set up my injectors for 0.7mS dead time, PWM current limit 35%, time threshold 1.0mS and PWM period 50uS.  Required fuel is calculated to 7.0 and set.


My mixture at idle is fluctuating between 13.9 and 15 or so.  Injector pulse width is running between 1.6 and 1.7 mS,  And the rpm varies between 850 and 1000, so everything is somewhat stable, but it seems like something is not quite dialed in.


If anyone is running a similar configuration, let me know how it runs and how its different from mine.

Edited by SleeperZ
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Took it in to emissions test with 5 gallons of 91 octane and 1.5 gallons of E85, but it didn't pass.  High CO (1.49%) and high HCs.  I thought it might be a bit too lean, so I reduced the mixture at idle from 14.2 to 13.8 and retested and all that happened was a worse fail on the CO (1.94%).  Because my idle is not as smooth as it should be, speed varies from 850 to 1000, and the mixture moves a bit as well, I am thinking I must be having some slight misfiring.  It drives very smoothly, but that's all I can think of.


If I can't get the idle figured out this weekend, I may have a track-only car.  Unless I can take it in to an exhaust shop and have a catalytic converter installed with flanges and a test pipe, that would definitely nail it.

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If I have the chance to do some tweeking with an exhaust analyzer, timing would be good to investigate.  I read on a different post here that someone determined that 20 degrees was a good idle timing, which is the factory setting for the L28ET.  I was running 18, but I will play with that a bit this weekend in my quest for a cleaner idle.

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Cleaned up all my plug wires after pulling the plugs and found 5 and 6 were leaner than the rest.  I checked the gaps and re-installed them.  Some wires were slightly loose, and noticed with a timing light that when the engine misfires I get a missed pulse.  I found my timing reference was different than what I expected too, and posted this on the MSExtra forums. 





Has anyone here experienced this weirdness?  I can get within 8-10 degrees with my trigger input, then when dial it in closer, it jumps to more than 10 degrees to the other side.  I used both the trigger wizard and the reference on the ignition settings, they both behave the same.

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