for some reason dfco is not cutting fuel to my engine when it is suppose to. I've fiddled for a while now and it's got me stumped. And it takes a while for the revs to drop off during gear changes or if i put my foot on the clutch.
for some reason dfco is not cutting fuel to my engine when it is suppose to. I've fiddled for a while now and it's got me stumped. And it takes a while for the revs to drop off during gear changes or if i put my foot on the clutch.
1996 c1500 gen1e 5.7L - the "LS31", 24x CNP, LS2 coils, modified T56, 12200411PCM running COS3, zz4 cam, custom MPFI, etc. coming soon: Twin Turbos
What are you changing to enable it?
Mine is bit agressive, but in the parrameters section this what I have.
LABELS DFCO M6 Enable Temp
Parameters Value
{B3307} DFCO Re-Enable Timer 0.500000 Seconds
{B3308} DFCO M6 Enable Temp 149.984375 °F
{B3309} DFCO M6 RPM 800.000000 RPM
{B3310} DFCO M6 MAP 12.328205 PSI
{B3311} DFCO M6 TPS 10.000000 %
{B3312} DFCO M6 Speed 1.000000 MPH
{B3313} DFCO Temp Enable 149.984375 °F
{B3315} DFCO Vehicle Speed Hysteresis 1.000000 MPH
{B3317} DFCO Throttle Hysteresis 0.996094 %
{B3319} DFCO RPM Hysteresis 0.976563 RPM
{B3321} DFCO MAP Hysteresis 0.144471 PSI
2002 ws6 stock short block
GMPP cnc LS6 Heads 11.4:1 cr
.576 i .581 e 116 lobe
D1SC @ 10#
723 rwhp 654 rwtq on E-85
Welcome to the site.
What tune are you running?
DFCO is one of those parameters where every parameter must be met in order to engage. You should always be able to compare the stock tune and copy and paste each parameter.
Depending on your tune, I always lower B3318 to engage it. Perhaps you are not reaching the DFCO RPM engage parameter if your rpm's are hanging.
If it keeps happening, feel free to post your tune up.
Last edited by WeathermanShawn; February 9th, 2010 at 11:31 PM. Reason: Grammer
Ok, I have met all the paramiters and everything is low enough to actually engage but still no luck, i've put the tune up if anyone can find where i'm going wrong. And it's definately not cutting fuel.
Never Enough TORQUE
It appears that your trouble is because you don't have B3310 high enough. Depending on you altitude. I believe the MAP value, decelerating with the throttle closed should about 14.7 psi. or atmospheric pressure.
I would also raise the value in B3316. A throttle position of 1.19 can be seen even when the throttle is completely closed if it's not adjusted properly. If this an ETC it will never see that # with the vehicle running. Raise it to 8% throttle
I modified your tune and will attach it. If it doesn't work follow the process below.
Get a log of what your MAP pressure is while decelerating from decent speed and rpm with the throttle closed.
Last edited by vatman02; June 27th, 2009 at 12:33 PM.
2002 ws6 stock short block
GMPP cnc LS6 Heads 11.4:1 cr
.576 i .581 e 116 lobe
D1SC @ 10#
723 rwhp 654 rwtq on E-85
Are your DFCO values stock?
I can see the DFCO parameters are obviously different from the LS1's, but those engage MAP's look really different. Mine does not engage until 20 Kpa.
Hope you get it worked out. I am a big fan of DFCO. Comes in handy going downhill.
Last edited by WeathermanShawn; February 9th, 2010 at 11:33 PM. Reason: Grammer
Thats the winner, I must of had a brain fart when I edited that because I remember lowering the value.
Never Enough TORQUE
great to hear, I gotta try altering my settings too once I get the truck back on the road. Thanks!
1996 c1500 gen1e 5.7L - the "LS31", 24x CNP, LS2 coils, modified T56, 12200411PCM running COS3, zz4 cam, custom MPFI, etc. coming soon: Twin Turbos