battery voltage

[Seight-v8]

hello all,

If my battery voltage shown in vems is changing by 0.30v, what effect would this have on my engine at idle?

Have read the battery voltage with my multimeter and its showing a steady 13.5volts, but vems is showing 13.5 to 13.76v....

what problems would this cause in the vems calculations?

And does this mean something's wrong with my earths or ecu?

Or again, just worrying to much.

cheers

scott

[Seight-v8]

So here's a 20sec vid, with car ignition on, engine not running.

Is this a problem?, as looks like the change in voltage is changing my pulse width, does this matter?

http://s875.photobucket.com/user/seight-v8/media/Westfield%20Kit%20Car/MOV_0051.mp4.html

cheers

scott

[UrSobsessed]

Pulse width is affected by voltage.  How much depends on your injector settings.  You need to take a look at lambda under various voltage loads to see the if the change is incorrect. 

[Seight-v8]

found the calc model overview, and the battery is not changing the pulse width in this window, only the map readings are.

I've always struggled with a 2-3kpa change here at idle, not sure how much of this is due to my cam though.

The strange voltage change in vems does worry me, need to do some more checks first.

cheer

scott

[VEMS]

Hello Scott,

Most DVM's apply a lot of filtering on the DC voltage measurements (for easy readout), Vems measures Vbatt over a 0-30v range with 0.117V resolution (not heavily filtered), the 13.5-13.7V fluctuation is not troubling at all. Since your reported Battery voltage is quite stable it is unlikely that this is the cause of your issues, i am confident Gunni will be able to sort it out for you without to much hassle.

Best regards, Dave

[Seight-v8]

dave,

thanks for the help/info....

I've moved back a step for the time being to look again at injector calibration, since I fitted new bigger injectors last year, I've never been happy with the settings for these.

I am trying the simplified settings instead of the traditional this time.

hope I manage to get this sorted.

scott