New T4 Microsquirt Install, engine runs poorly

[svenjamison]

Thanks in advance for taking the time to read/assist.

First install of microsquirt here, not able to get engine to run well at all. Bought a motor from a friend who purchased from engine builder years ago, fresh rebuild. 2412 type 4, 280/.488 cam, large valves, 104mm pistons (builder originally specified dual 45 dells). Basically a high revving hp heat machine.

Though it is probably the worst configuration for my application (camper), price was right, and it was intended to be a temp engine while I figured out my Camper Special build. Originally attempted to use stock L-Jet, which had worked great in previous engine, ran fairly poorly with this one (assumed due to L-Jet not being able to keep up with big cam), but was able to break in the cam and get it to at least drive, if not idle. Decided it would be a good time to finally convert to MS. Originally went fuel-only, which ran (again poorly) for about 5 minutes on points, until R20 (opto) fried and lost RPM sig. Heard that is a thing. Ordered Dubshop 36-1 wheel/hall sender, paired with 032 905 106B 4 tower logic coil, wired to VR1-/sensor ground/5v vref. Checked timing with simple timing light and corrected tooth angle to 85 deg.

Smells real rich when running, has no chance of idling, basically unusable at any RPM. Engine appears to flood, and will only pop again when cranking with fuel pump fuse removed. Can get it to run poorly at about 1200 RPM, any attempt at more kills the engine. All plugs appear fouled, black carbon all over. O2 pegged full rich. There may be an issue with O2 comm, so disabled incorporate AFR target. Any ideas? I am concerned the engine itself has issues, or too wild a cam to run anything but giant carbs. Shouldn’t the basic tables at least run the engine somewhat well? Have tried 4 squirt/2 squirt in both simultaneous and alternating. Set timing fixed to 10 deg, verified with timing light. Have a dual battery setup running lithium iron/lead acid, combined voltage is usually near 14v, solar panels on top, so low voltage not an issue. Below are specs, some screenshots. Thanks!

Microsquirt v3
New Hi Z vanagon injectors
Stock L-Jet air box/TB/plenum/runners/pump/FPR (afm flapper held open by spring)
INJ 1 output wired to Cyl 1-3
INJ2 output wired to Cyl 2-4
VW 4 tower wasted spark logic coil
SPK A output wired to Cyl 1-3
SPK B output wired to Cyl 2-4
3 BAR GM MAP
GM IAT and CLT
PLX Wideband
No TPS (signal wired to sensor ground)
Vacuum referenced from plenum feed to FPR
Wired according to manual, grounded ECU/relays direct to battery, 2 relays (ECU/Everything else)

[svenjamison]

settings.jpg

ig.jpg

[svenjamison]

ig.jpg

[luftvagon]

I have a T4 with Microsquirt with similar configuration, sans cam. I'll give you a few things to look or change.

[luftvagon]

First, what version of ms2extra are you using? Post setup pictures.
All sensors calibrated? Battery calibrated using suggested values?

Under Engine and Sequential Settings, change req fuel to 17.9 and timing trigger to End-of-Pulse

Under General Settings, set all LAG Factors to 100 (we will work on this later)
Table size 16x16, and don't include AFR...

You have not posted your injector dead time.. I have HighZ Vanagon injectors as well and this is my setting
Injector dead time: 1.09, 0.262 ms/v correction.

Over-run fuel: off
EGO: off

Turn off all after start enrichment, zero it out. You will have to work that in later.
WUE, start at:
-4F,140%
68F,125%
198F,100%
and interpolate values in between.. smooth out the curve, and then play with ratios...

Ignition..
Cranking Dwell: 3.5
Cranking Advance: 7.5
Nominal Dwell: 3.0
Spark Duration: 3.2 ms <-- important.. yours is 1.0ms; not enough spark i think!? Someone please correct this if this is wrong.

I took a SVDA curves, and built my own ignition table to resemble stock. It's available somewhere here.

Hold pedal to the floor, and start the engine, back off as soon as the engine starts, and try to hold IDLE at 1500 RPM until engine warms up.. commence tuning.

[sacr32]

I don't see a cam sync listed. Turn off the sequential.

What fuel pressure?

[luftvagon]

Semi-Sequential works with crank trigger.

[svenjamison]

Luft: thank you so much for the detailed response, truly appreciated. Running msextra 3.4.2. MAP/IAT calibrated to GM, PLX wideband set to Innovate/PLX preset. Attempted start using all of your settings, condition is about same. It seems like it would at least run with rough settings, this seems much worse. Tomorrow I will adjust valves again, perform a leak down test and test fuel pressure just to eliminate those variables. Fuel pressure within spec before going MS, new pump/filter/lines. Might pick up a can of starting fluid just to see if can be made to run more smoothly on that, which would I suppose at least get me better resolution on whether the issue is fuel or spark related.

[luftvagon]

Did you hold the gas pedal half way? This could just be a cold startup thing. Can you keep re-starting it and trying to get it to warm up? Post your fuel map too. Did you calibrate battery?

[svenjamison]

Worked the throttle in every position manageable, got it to warm up for a few minutes, completely gives up at that point. Restart attempt leads to apparent flooding. I have absolutely no idea how to calibrate the battery. I see the dwell batt correction setting, nothing in the manual/help doc gives me any indication whatsoever of how to accomplish calibration, feels like sections of the manual state in so many words that "this setting exists, good luck". I VERY well could be missing it tho. Ha. Checked valve adj. and compression today. All cylinders sitting at 110-115psi, lash in spec. Tested coil/wires, found that 2 towers were throwing weak sparks (used same wire/plug on all towers). Plug wires all check out. I attribute this to purchasing non-oem (ebay/so very cheap) coil pack, have Bosch OEM unit OTW to verify. Recently replaced plugs, gapped at stock spec for t4 points/dizzy (small), do I use gap spec for original coil application (VW 2.slow AEG)? Keep in mind I had previously installed plugs which were gapped wider for my Mallory Hyfire, so I don’t attribute my current issue to those. Fuel pressure re-checked, steady 40psi in test mode. Speaking of test mode, was unable to start tests for firing coils/injectors. Enabled test mode, set spark from off to one, same for inj., no love.

Anywho….

[svenjamison]

ve.jpg

VE table. Stock one from software I think. Also, have that coil zip tied in place currently, does it get any other ground signal through the mounting holes, or does that all happen from the ground wire in plug?

[luftvagon]

All ground wire plug.

Make sure you calibrate battery.


Make sure you have PRIMING OFF (set to 0)
Set cranking to:
-4F,170
68,140
178,100
198,105
(this is from memory.. my laptop broke with latest ChromeOS update - need to pull the file over)

As always, it's best to capture a log file after these changes.

It should not flood with those settings. Req fuel is low enough, and your values are low enough; that if anything should start, and run lean and like crap.

TunerStudio log will tell us more now.

[svenjamison]

K. More research done. Unless I'm mistaken, for batt. correction measure actual batt. voltage with VM and compare to TS reported value, adjust supply voltage max ADC till values line up. Will do tomorrow. On another note: Does there somewhat exist a good tutorial beyond the TS manual (and searching forums for days on end) for all these things? Just seems like lots of glossing over what everything does. Ok, thanks again.
James

[luftvagon]

Calibrate battery to the recommended values provided in the TunerStudio.

[luftvagon]

any updates?