Ha ha, the shed clean up was step one of a three day car bender that started Friday. A Holden Astra, Mitsi Pajero and then the 300ZX were all worked on in that space over the last three days. But that is where the Zed always sleeps come night time...
Jayme, the auto pcm + 11P update is definitely on the cards to drive the temp display in the dash. First we need to get the fuel injectors working in Rosco's 240Z before a track day on the 18th Jan. Mine's track ready until then, with the oil temp gauge and the delco 'check engine' light as over-temp warning signs.
DelcoWizz, the original ECU and electrics in the Z31 were so bad I am not surprised someone has converted it to a reliable old carburetor. I hate to think how many of this model have gone to the wrecking yard because of a simple but hard to diagnose sensor or electronic fault
Now another update on an issue I think I nailed today. Up until now I've had an issue until the engine has reached a good working temp (~70 deg C) where when you step on the accel the engine goes rich and almost stalls. It then picks up RPM and the AFR levels out, but you needed to ease in the throttle for the first few minutes of running otherwise it would flood and stall. It was pretty annoying but as we had bigger fish to fry I just accepted it for a while. Even once it was warmed up it would give a little cough and lag a bit when you stepped on the go from idle, occasionally stalling. It also left big black nasty marks on the grass or concrete where it was started and rev'd to warm up.
But today I went about resolving the problem, and here's what I did.
Firstly the VE table looked a little odd to me, way down low. You can see (left image below) the region 20-60 kPa from 0-2K RPM seemed to drop right away. To me this seemed a little strange, and I know we built the table with generally rich AFR results which probably screwed our calcs so I smoothed this out in respect to the rest of the table. Results below on the right.
- Z31 VE 001.JPG (83.59 KiB) Viewed 8571 times
Also I found the "MAP A: A/F Ration - Initial Run A/F Ratio Offset vs Coolant Temp' table which seemed to the reason I was getting target AFR of ~10:1 on startup. In the 30 deg C coolant region it was offsetting my target AFR down to 8.5:1, and leaving black soot marks on the floor of the shed. I changed the settings from original on the left below, to the new on the right below:
- Init run AFR offset.JPG (35.3 KiB) Viewed 8571 times
A test run after these changes showed good results. It was running less rich and responded better to a tap on the go pedal. But it was still not right, giving a cough and for half a second sounding like it would stall before roaring to life. The AFR was still dropping to ~10:1 as this happened so I looked a little further and found the acceleration enrichment table "AE - AE temperature factor vs coolant temp'. Not really knowing what I was looking at, but knowing at a high temp that things were much better I adjusted the lower temp values accordingly. Not knowing where to go I threw roughly half values in at the critical start temperature (South Aussie summer) and smoothed things out either way. The change was immediate and awesome. No more black smoke and soot marks, no more coughs and half stalls, it just goes straight to angry Nissan V6 noise mode!!!
Before and after values below:
- AE temp vs coolant.JPG (33.38 KiB) Viewed 8571 times
Disclaimer - Now this was all done with the trial and error method and with no consultation with professionals, technical documentation, tea leaves or google. I did ask the dog what he thought about it but his input was negligible. The results seem good sitting in my shed, but until I borrow a trade plate or actually register the car the real world changes are unknown. I am just posting it here to gauge opinion and perhaps a warning in case I have changed something that I shouldn't have...
Has certainly had some mods done to it during the build.
About the only plus side to having 360 dizzy slots is the cranking timing can be adjusted in 2deg increments 
