VEMS Community Forum

Technical => Ignition => Topic started by: Seight-v8 on June 04, 2010, 08:30:43 AM

Title: mis-fire
Post by: Seight-v8 on June 04, 2010, 08:30:43 AM
hello all,

is it possible to detect a mis-fire from the logging in vemstune???

Still finding my way...and need to know if its possible to spot one...

As my knock readings on idle are bouncing all over the place....and not sure if this is a sign of mis-firing...

Engine feels like it might be mis-firing every few seconds....but not sure.

cheers

scott
Title: Re: mis-fire
Post by: dnb on June 04, 2010, 01:07:46 PM
Yes, I think I have a way if your datalogs include the tooth timing info.  Post up a log and I'll do the calculations.
Title: Re: mis-fire
Post by: Seight-v8 on June 05, 2010, 10:06:39 AM
hello dave,

took me  a while, but i just made my own members page.....

http://www.vems.hu/wiki/index.php?page=MembersPage%2FScottRichmond (http://www.vems.hu/wiki/index.php?page=MembersPage%2FScottRichmond)

So uploaded some pics & latest config to my virgin account...

Still its in progress....and will add some more stuff soon.

cheers

scott
Title: Re: mis-fire
Post by: Seight-v8 on June 06, 2010, 01:28:54 PM
still trying to understand why at idle my logs show the spark angle changing from 5-8 degs.....

yet it should be 9-14degs as set in the spark table....

still un-decided if this is a mis-fire...as nothing else is changing in the log for the spark angle to change....

thought i would see...a constant spark angle...unless i have a problem coil pack??

scott
Title: Re: mis-fire
Post by: dnb on June 06, 2010, 02:59:26 PM
Have you got ignition ratard based idle control enabled?  This would give strange log readings.
Title: Re: mis-fire
Post by: MGV8 on July 10, 2010, 06:28:00 PM
Hi Seight-V8

Is it possible to get a copy of your config file. I am trying to get my MGB V8 running with Vems - and have problems with getting ignition right. Started with ignition (waste spark with two Bosch coils), still running cabs.
Engine is running but not as good as on dizzy :(

Thanks Søren - Denmark
Title: Re: mis-fire
Post by: Seight-v8 on July 11, 2010, 05:38:12 AM
Søren,

If you PM your email address, i will send you my latest config file.

I am now running V1.1.78, but can send you some previous versions if you need it.

regards

scott
Title: Re: mis-fire
Post by: MGV8 on July 11, 2010, 08:47:52 AM
Hi Scott

It is fine with V 1.1.78 config as I have just upgraded my Vems to V1.1.78 firmware.

My mail: [email protected]

Nice car you got, it must be pretty fast!

Regards Søren
Title: Re: mis-fire
Post by: Seight-v8 on July 11, 2010, 01:03:18 PM
done,

you should have an email soon, let me know who you get on.

regards

scott
Title: Re: mis-fire
Post by: MGV8 on July 12, 2010, 03:19:03 PM
Thanks for the config file.
I use it as starting point for tuning of ignition map, and when I install injection as basic setup for fuel. I’m waiting with installing injection to I have ignition running smooth and stable.

I still have problems with ignition seems as one of my coil packs are defect. Four of the cylinders 1-6 and 5-8 are not burning good â€" based on examine of plugs after a drive.

The car hesitates when given full throttle and some times misfires. Some times it feels as it pulls as it shut for a short time when accelerating.

Have you any experience with dwell settings? 

When test with timing light it seems as sometimes ignition are missing on cyl. 1 but cyl. 6 ok, and that’s the same common coil!

I have tried to connect LED´s on input to coil pack and seem as signal from Vems is ok

Must be a defect coil pack!
Title: Re: mis-fire
Post by: MGV8 on July 17, 2010, 07:59:05 AM
Changed coil pack, and engine running perfect with wasted spark. :)