quik95lt1

iTrader: (7)

Been having some misfiring issues with my car and i think i just stumbled across the issue.........i decided to drive the car to work this afternoon and data log the whole drive and see if i could find anything.........sure enough 14 minutes in i get this picture on the graph...........now this took place over a duration of only 85mS so it was tough to see i stubled across it durring zooming in.........if the noise was less that 50ms my data logger wouldn't have picked it up yet the ecu would have processed it..........i got lucky i caught one big enough to see...........looks like a false voltage is being induced on my cam trigger wires and causing the xfi to get a bad reading..........you can see the timing goes so far out of wack for that split second that the motor nearly shuts off and I audibly heard the motor stumble when this happened. Look at the 156* in the cam sync and the 1.75AFR!!!! Looks like grounding my unused inputs and re-routing a sheilded cable may be the answer......figured id share this i found it interesting........

heres the pic from the data log on the CCom software..........

ZFreie

Nice eye, you managed to catch a gremlin. I bet your happy.

Wicked94Z

iTrader: (26)

what's the cam sync deal you're running now?

quik95lt1

iTrader: (7)

i unplugged it and went back to bank to bank for troubleshooting purposes........i unplugged it right at the ECM too.........thats why its even more screwed up........it should just sit at 0

quik95lt1

iTrader: (7)

im frickin souped man!!!

maybe now i can go stomp some serious passes after i fix it

draggin97s10

iTrader: (2)

Nice catch man.

ZFreie

Now go wrangle that 9.xx pass

05HD

That isn't much to go on but at least you now know one channel that is being effected.

You aren't using non-resistor spark plugs or wires by any chance, are you? Those are the common causes of RFI/EMI I have found over time and a ton of bashing my head against the wall. Also, a poor alternator will do it...

Wicked94Z

iTrader: (26)

coil/ignition box placement and where they're grounded could cause some issues... I'm not giving the electrical engineer any advice though

quik95lt1

iTrader: (7)

It's plenty to go on!!! That shouldn't ever do that no matter what, its a great example of catching an issue masked by to slow a sampling rate of a data logging system. At least now i know the road I need to go down. Going to start working on it tonight.



yea the box is farrrrrr away from the xfi and all the other stuff as is the coil but im going to reroute some sheilded cable away from plug wires and stuff to make this work better...........and im always open to ideas.......just because im an EE doesn't mean i know everything lol.....

gregrob

iTrader: (8)

Pretty sure nitrous fixes that ****.

Wicked94Z

iTrader: (26)

it looks like it's sampling at 10/sec? I do 10-20 on mine, but sometimes I got problems with the serial adapter causing it to lose connection at 20. That usually happened only between the burnout and staging