[jonbill]

Yes, I have the same axes for all 3 load/rpm tables, you can find them all in the attached tune

[Chris Wolfson]

Hi, I'm doing Alfa TC engines for 40 years now, maybe I can help a little. Advance is not very extraordinary on them. 38° is the most they need. Important is to check the ignition advance and adjust the zero. 10° should get it running, if not the numbers in TS do not match the engine reality.
Best is to find out how much advance your pulley has at the idle advance mark. Then set this number in TS as fixed value (same ° at any load/ rpm situation and check with a stroboscope light.
If this is spot on (you set some kind of offset in TS), you can do a simple advance curve to get startet, like rising from 10° at 800 rpm to 34° at 4500, then keep that until the limiter kicks in. Will not be the best you can get, but make no problems, so you can get a decent fuel tune. Later you can tweak ignition, but that is a secondary problem.

Your stock 2000 has 32mm venturis in the 40 DCOE carb, that will give up to 140 HP. So, with 40mm you can make some serious power, if compression ratio, cams and exhaust permit. As the injection does not need air speed to suck in fuel, you should be able to run such a huge diameter (compared to carbs you would have to run a 50 DCOE) without problems.
The Injectors are well sized with 350cc, just keep the pressure at a reasonable value. 3 bar should be fine.
We had the "no return line" problem before, most regulators ONLY work that way. So your problems probably come from unregulated 5-6 bar fuel pressure, which is all the fuel pump can do. Only modern cars do pressure regulation by the ECU. You have to do it mechanically.

[alessandromeyer]

Thanks @Jonbill

@Chris Wolfson

I already laid out the ignition like that and drove it some km back with my Solex Carbs on. It was sort of the first step to learning while always being able to go back to dizzie when there was a problem. I actually went your way and did 9°-34° to keep things safe. Problem was at first to set the timing right since the TwinSpark (Alfa 75, which i used because of the 60-2 teeht) Pulley doesn't have any markings at all besides TDC.

I have a return line and mechanical pressure regulator but on the filter (https://i.ebayimg.com/images/g/QVgAAOSw ... s-l300.jpg VW-type) and not after the ITBs, which is better I understand. So pressure should be still between 3-4bars. I will verify this with a mech gauge in brief time.

Btw I plan to install a spiced up TwinSpark from which i borrowed the pulley eventually the 40mm should come in handy then. But first I want to learn all about it with my trusty, original to the car nord engine.

Thanks guys.
-Alessandro

[alessandromeyer]

So I think I managed fix my lambda probe and at the same time i fixed airleaks i had after the throttle plates. I made my first short drives around the block. I struggled a lot with some plugs not firing due to fouling which put my lambda readings totally of and put me totally of with first manual tuning.

In any case i started my first log and would love to read some experienced peoples opinion what they read out of it. no big rpms yet not much throttle yet but what I see is way rich on AE/accel - am I reading that correctly?

Thanks a lot,
Alessandro

https://github.com/AlessandroEmm/AlfaTu ... .21.04.mlg
https://github.com/AlessandroEmm/AlfaTu ... ntTune.msq

[jonbill]

I'm not sure if I qualify, but: I don't think your AE is terrible actually - quite often in your log where there is AE, you immediately lift off the throttle which causes enrichment anyway (sort of the opposite of the leaning out that happens when you open the throttle).
And you're quite rich to start with form most of it anyway, because it's still in WUE.
I think the advice would be to level AE out at 100% so it has no effect while you're tuning the VE table.
I tend to get it warmed up completely before I start logging and I use a RPM/TPS/AFR histogram in megalogviewer a lot, it's really good at showing you where you were rich and where lean over the whole log.

Screenshot 2021-08-06 at 17.54.28.png (1.06 MiB) Viewed 3968 times

[theonewithin]

The correct procedure to tune is to disable all fuel modifiers and run off VE table only.

So set all enrichment settings to 100% for all temps/times/everything.

Get engine running and up to fully warmed up. Do your idle cells in the VE table and all of the immediately surrounding cells.

Once this is done THEN you can start working on modifiers.

Everything relies on your VE table. If it's crap or incomplete or you are changing things not understanding that everything uses the VR table as the reference, you can end up chasing your tail for problems that you are causing yourself without knowing.

Tuning needs to be done methodically.

[alessandromeyer]

Thanks for looking into it @jonbill @theonewithin

I also thought about the effects of running without AE, but wasn't sure whether that would cause my tuning to be richer - to be able to accel without going very lean, especially since this is an ITB system. How did you guys manage that (the acceleration without the "help" of AE?

Thanks again,
Alessandro

[jonbill]

I Confess I didn't follow the advice

[LAV1000]

Thanks for looking into it @jonbill @theonewithin

I also thought about the effects of running without AE, but wasn't sure whether that would cause my tuning to be richer - to be able to accel without going very lean, especially since this is an ITB system. How did you guys manage that (the acceleration without the "help" of AE?

Thanks again,
Alessandro

Just be gentle on the throttle pedal.

[theonewithin]

As above. Gentle gentle.

You can enable AE usually pretty quickly as it should only.kicm in when you give it some so it's relatively easy to diagnose.

Just get the VE table to a point we're it's drive able and go from there.