Jump to content

Difficult cold start with E85 - WRX6


DenisAlmos

Recommended Posts

Hi all,

I'm a just a beginning to learn how to tune but I need to fix a problem before I go farther.

 

Today I parked my Impreza outside for the first time and it was cold with frost.

I could start it only after 7 crank 3s long...

 

How can I make the startups easier? Should I add ethanol at pre-crank prime and crank enrichment?

 

Can you send me settings that works properly with E85?

 

This is my actual settings

image.thumb.png.16b9e518fe00234ae54268db12ceb8a4.png

Link to comment
Share on other sites

@Ben C,

Thanks for the tip, I added enrichment and it's much better, perfect in some cases and a bit longer under 10°C. I'm waiting for colder than 10° weather to confirm my settings works.

 

@koracing,

I'm using the stock 440cc WRX V6 injectors.

Sometimes the check engine light comes because the injection have reached 102% injector duty cycle but I think I'll just decrease the boost to do not have to change the injectors.

 

I'm more focusing on Idle settings now and it's horrible now it can work properly one day and don't on the following one...

If you have any tip for Idle Control with a stepper motor, I'll be please to read you!

 

There the Cold Start values i'm using now:

image.thumb.png.786a87cb12dee51e00d50ae687dd89e2.png

Link to comment
Share on other sites

I would add some pre-crank prime as well for those injectors.  For stepper motor I would recommend trying setting it to open loop and work on what stepper values give you near the idle you want by setting them manually, then turn on closed loop after you figure out what works for your car and can make a curve that work well.  Idle ignition control can make a big difference as well, but probably it is best to try and tune fuel and stepper motor position for all idle areas without that turned on first.

Link to comment
Share on other sites

@koracing,

Alright, I'll try with some more pre-crank prime enrichment

My problem with open loop is every time I think I have good numbers, it doesn't work the following time. For example, with afternoon I did this log. With the stepper motor at 30% and engine at operation temperature. It worked well. I stopped the car and started it again and then the engine was very on RPM at idle for the same conditions of stepper position, MAP and temperature. However, as it was lower on RPM the ignition advance was lower, following to the Base Map ignition.

I tried to hit the throttle to see if changes something but didn’t.

image.thumb.png.8f05bd9cc2b4250ee003769192c8f8a6.png

Idle30Perfect_Restart30NOK-11-28 4;55;59 pm.llgx

Link to comment
Share on other sites

I don't know what do you mean by homing but when the engine is not running, the stepper goes to Base Position + Startup Offset. In the log it is 30 of Base Position and 8 of Startup Offset.

My hold power is set to 30% but I'm to sure to understand 30% of witch value?

image.thumb.png.05afc9c7ce34bdf04515f68855282760.png

Link to comment
Share on other sites

12 hours ago, DenisAlmos said:

My hold power is set to 30% but I'm to sure to understand 30% of witch value?

Koracing was talking about the hold power keep alive time.  This is how long the ECU stays powered up for after you turn ignition off to allow the idle motor to reset to its home position.  5 or 10 seconds will do for a WRX.

4Y6M7XI.png

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...