Please help me with cold start tuning?

[ravensierra]

Hi all,

Was hoping to get a bit of help with the cold start tuning on my daily driver if possible.

It's starting to get into winter here in the Southern hemisphere, had our first frost a week or so ago, would expect to get down to a low of maybe -10*C (14*F) at the coldest.

Anyway I didn't have the cold start table prepared properly and managed to flood out a set of plugs (which are real fun to change out on a transverse V6).

I tried reducing the cranking PWs on the day as well as TPS-based flood clear but couldn't get a fire.

So usually I have to pump the throttle a bit when it's around 5*C CLT, from what I gather this means I should be reducing my cranking PWs?

At 0*C (32*F), my cranking PW is 300% of req_fuel, which is 5.9ms.

Would this be generally considered to be a high figure?

[Matt Cramer]

Please attach a data log of the problems you're having.

[ravensierra]

I have a single datalog on my computer, will UL it after work, on my phone at the moment.

Is WBO2 data any use during cold start troubleshooting? Mine is powered off an ACC circuit and gets power cut during cranking

[ravensierra]

Attached is the datalog I have, please excuse the fact it is zipped, it was a 5MB file.

This log was taken after drying off the front three plugs in the afternoon, CLT is up to 14*C. As I said, the wideband data doesn't appear until 10 seconds or so after cranking is complete, I can of course get 12V for it off the non-ignition switch circuit I use for MS to keep the controller live during cranking.

I know this data probably isn't useful...

What kind of log should I be aiming to take? One around 5*C where it will catch and run with some throttle, or one around 0*C where I flooded the plugs out and no start? The weather has warmed up to around 7-8*C in the morning for this week.

Thanks,

Jack

[Matt Cramer]

That data indicates a problem with cranking pulse width. We have some tips on tuning that here: http://www.diyautotune.com/tech_article ... uning.html

[ravensierra]

Thanks Matt, that's clearer than any other info I'd found.