Tuning advice for Perfect power

[GT08]

Hi Everyone,

Bit of a long winded setup, for those what would like to stay and read, this is about aftermarket EFI tuning and problems with the cold (not like winter specifically, just first start and drive).

I drive a 1992 Mk2 Jetta with a 2.0 ADY. I have converted it to EFI with a Perfect Power XMS 5b
I am running a coil pack with wasted spark (60-2).
I am using the throttle body from the ADY, and the XMS is not setup to control the idle motor in the throttle body.
I am running a Bosch LSU wideband lambda sensor, with Short and long term fuel trim.
When cold the engine idles at about 700 - 850rpm, up to temperature about 900 - 1000rpm (I know this is high for both cases, this might contribute to the problems I am having).
The throttle body is stuck open ever so slightly so I did not install an idle (grub) screw as this was not needed.

There are a few small problems that I would like to try and sort out myself.
I know I can go to a tuner but these are really small inconveniences at best so I would like to try and fix myself first.

If any of you can provide general tuning advice or tips for diagnosing the problems, that would be great.

The first problem that I would like to sort out is stalling when cold and pushing in the clutch.
Sometimes the rpm drops to like 100rpm and then the management saves it, raising the rpm back to idle rpm.
The engine idles smoothly and drives fine when cold. The management shows that the idle AFR and timing are fine (according to the current settings).
When the engine warms up this goes away completely.
I have been forming a bad habit of just letting out the clutch slightly when it does stall to start it again. This starts it right up, so no restart issues.
When this happens I can see the AFR go really lean (like 35~). This makes senses as the management will cut the injectors to save fuel.
What I have tried:
- Disable the AFR for the idle load sites
- Decrease the max adjustment allowed by the AFR trim from 8 points to 1
- Increase and decrease the base timing for the idle load sites.

The second not so important problem is cold starting.
The engine now in the colder time will start fairly quickly on first attempt and stall directly with no user input. The second start is a bit more difficult.
I can get the engine to start first time with no problems if I give a little throttle, but no too much as this causes a stall directly.
Once started and idling the engine is very happy and will start again right away regardless of how cold.
It seems the settings are really close but not there yet.
The cold idle is spot on according to the chosen AFR so I did not adjust the temperature fuel load sites a lot.
What I have tried:
- Increase the start enrichment load sites for current temprature. This seems to have gone too far a few times and you can smell fuel.
- Almost start over with the cold enrichment map and start increasing only when struggling to start

I mainly have a problem in diagnosing the problems, and knowing what to look for. For example when really cold the wideband (heater) is cold so after starting I cannot use that for any diagnosis.

Thanks in advance

[Neuk]

Go to @panic mechanic for a basic setup and tune, I am sure he will discuss some techniques with you so you can tweak/diagnose in your own time.

[GT08]

Go to @panic mechanic for a basic setup and tune, I am sure he will discuss some techniques with you so you can tweak/diagnose in your own time.

Thanks, will do so.

[panic-mechanic]

Really hard to do that kind of thing on the forum or phone. Much easier to show somebody face to face what to look for.

[GT08]

Really hard to do that kind of thing on the forum or phone. Much easier to show somebody face to face what to look for.

I understand, every engine is different and every person does it a little bit different. It just feels like it is so close. Just a few small changes should make it a lot smoother when cold. It drives almost perfectly when up to temp.

[panic-mechanic]

So pm me for contact and address then Come visit and I'll show you what you need to know.