Jump to content

Cold start excessive cranking


Recommended Posts

Good morning fellas,

I've been having some issues with cold starts lately. Resorting to the forum is my last option as I have tried everything that has been recommended in the forum before.

I have added fuel and removed fuel with no success. Currently it is cranking excessively and once it does start the AFR's drop into the high 9's for a short period of time. The guys from work have noted the amount of fuel soot out the tailpipe when I drive away as well. Does the injection timing have a large effect on the start time?

Any input will be much appreciated. Log and PCL attached.




Nissan Y34 Gloria - Link Thunder 09.08.18 v2 - Idle stepup added.pclr

Log 2018-08-9 9;10;05 pm.llg

Link to comment
Share on other sites

Interesting that you are using Charge Temp Correction with Traditional Fuel Mode? I noticed the Fuel Table has an odd shape and very little range, normally the numbers should increase as load increases.

Link to comment
Share on other sites

@Leiden I realised this after I had spent the time tuning the fuel map on the dyno after having issues with tuning the VE model. Will rectify this once I get back onto the dyno. As for the odd shape in the fuel table, I don't know why it's like that. Will try to change back to the Modelled and see if I can figure it out. 

A little update from this morning - I found the ignition timing on startup to be very advanced (29 degrees). After fixing pulling some ignition out of the map it seemed to start better this morning. I'm slowly learning how to tune and the Link G4 software. I appreciate you highlighting these issues and I will try to address them as best I can. 

Cheers - Jacob

Link to comment
Share on other sites

I found Traditional Fueling is a lot easier to get up and running, especially if you are new to tuning.

I'd disable the Charge Temp Correction, your also using the Open Loop Lambda table which means there is some behind the scenes correction to your Fuel Table based on the AFR/Lambda Target Table so it might pay to read up on that to help you understand whats going on.

Link to comment
Share on other sites

@Leiden I'll have to do some touch up's to the fuel map once I turn the Charge Temp Correction off but that's not too much of an issue. I had weird VE numbers in the table when I was trying to use the Modelled fuel and couldn't find the cause so ended up changing it across to MS based. I'm used to working on the engines not tuning them but this forum and community has been very helpful!

The Open Loop Lambda is active but I've changed the temp activation to above 120 degree's (which I would hope this engine never see's that temp) so that I can get the fuel map some what close.

I've attached this morning's log with the timing removed. I'll import the Crank Enrich and Startup Enrich maps for the 350z VQ35 which should be the closest to the VQ30 and try them tomorrow. 

Log 2018-08-10 8;55;12 am.llg

Nissan Y34 Gloria - Link Thunder 09.08.18 v2 - Idle stepup added - Timing removed.pclr

Link to comment
Share on other sites

I think you might be confusing Closed Loop Lambda and Open Loop Lambda. Closed Loop is based on feedback from the Oxygen Sensor whereas Open Loop Lambda works as an overall correction to the Fuel Table based on the Lambda Target Table.

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.

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...