Cold start problems / firmware upgrade 1.1.27 > 1.1.xx

[epic]

Hey !

I have a VEMS unit with firmware 1.1.27 on an Audi AAN engine having cold start problems. Maybe the solution would be a newer firmware which has more advanced settings for this. Question is: how can I upgrade from 1.1.27 to 1.1.8x firmware ? I can see that simply uploading the old config doesn't help here.

So if you please can help me with this...

[mattias]

The configuration file will be saved before upgrade and after the firmware upload completes will be uploaded with new default settings for the added/new settings.

Use latest VemsTune and firmware 1.1.84.

[epic]

Would you please take a look at my config here: http://www.turvaauk.ee/vems/v3.3_n001061-A-2010.12.18-21.35.15.vemscfg

Tha engine needs about 5 seconds of cranking with say +10C, but it always starts with warm weather. Now it's -15C outside and the cylinders got flooded. CLT is calibrated and shows ok, maybe +/- 3 degrees. So what should I do ? I'm using 1.1.70 firmware.

Thanks !

[mattias]

Too low value for afterstart time  cycles with cold engine, and overall too low afterstart enrichment table.

Too high cranking VE% value, perhaps inflated due to using wrong values in cranking, afterstart and warmup tables.
Also check the injector settings and squirt simultaneous with divider 2, it promotes easier starting and usually means you have to use a lower cranking VE%.

Borrow tables and settings (drag and drop on dialogs) from this file :
http://www.vems.hu/files/MembersPage/MattiasSandgren/vemscfg/audi-s4-2010-10-05.vemscfg

Are you using idle control at all??
Don't use the settings from the file above for that, idle wasn't tuned and ready to go.

[epic]

I'm not using any idle control and the IAC is unplugged because then I connect it to VEMS, the rpm is between 3000 and 4000 and changing of the settings has absolutely no effect. Seems to me that the output is somehow damaged. Do the idle settings have any effect on cranking ? What I mean is do I have to open the throttle a little to help starting it or should I start it with 0% TPS ?

[mattias]

When you have no idle air control valve you must always give some throttle when starting to avoid flooding the engine. It's tricky, because with a cold engine you don't need much air initially - but once it fires you have to give it more. With hot engine you can easily flood the engine if you don't provide some throttle while cranking.

Use the IAC lock function (Tools menu) to see what the valve does with different input.  You can use the settings from the file I linked to, at least initially.

[epic]

Today I connected the idle valve to a different output (EC36-17) and it works. So I understand that the original idle valve channel (injector output 6 - EC36-6) is always grounded. Does that mean the smoke has come out from a transistor somehow ? If so, can you tell me what type of transistor should I buy and solder there ?

[mattias]

They usually break because of improper flyback protection.
http://shop.vems.hu/catalog/injector-wbo2-heater-driver-p-30.html

If you make an order for that unit, ask for the FET that they use on the latest boards which are not insulated and harder to kill.

Did you get a PnP unit or did you build your own harness and used a regular ECU?

[epic]

It is a PnP unit with Motronic-55 connector.

Please take a look at my conf here:
http://www.turvaauk.ee/vems/v3.3_n001061-2010.12.23-14.08.45.vemscfg

Under Rev Limit / Overrun / Safety the Fuelcut RPM is 4000 because if I set it to 1600, the fuel is cut on accelerating. Now it runs OK but cuts the fuel AFTER any harder acceleration for about 2-3 seconds. What could be wrong ?

[epic]

Can I disable the overrun function somehow ? I don't know why, but it cuts the fuel on acceleration if I set the Fuelcut RPM value to 1600. So now it is set to 4000 and it is at least driveable, but cuts the fuel after acceleration.

My settings look like this:



What should I do ?

[mattias]

Increase the resume rpm ?
If you rev past 4000 rpm with the settings above, it will cut fuel and not resume until 1500 rpm.

You should set pressure cut limit to 0 and only use the rpm based, or the other way around. It usually works out best that way.

[lugnuts]

I always use Pressure to cut for overrun. I have had problems (unwanted cutting) come and go using the RPM cut.

Set the RPM settings to 9,900 or something high that will never be reached. And use the KPA to cut. 
Drive the car in third gear to 3,000 rpm, let off of the throttle, and see where the MAP goes down to.
Make the cut a few kpa above the lower MAP value you see.
Make sure it is well under the value you see then cruising at 1% TPS.