DFI - Timing at Idle
Thread Starter
Racer
Joined: Feb 2000
Posts: 488
Likes: 28
From: Peabody MA
DFI - Timing at Idle
I'm using the older Gen6 version of Accels DFI. Currently I have the cell that the car idles on and those around it set to 22. What's a normal range for timing at idle? I just want to make sure I'm in the ball park.
Any ideas would be great.
-Mike
Any ideas would be great.
-Mike
Drifting
Joined: Jul 2001
Posts: 1,897
Likes: 0
From: La Fontaine Indiana
Re: DFI - Timing at Idle (Mike in Boston)
I'm using the older Gen6 version of Accels DFI. Currently I have the cell that the car idles on and those around it set to 22. What's a normal range for timing at idle? I just want to make sure I'm in the ball park.
Any ideas would be great.
-Mike
Any ideas would be great.
-Mike
22 should be ok as long as it is in sync.
Thread Starter
Racer
Joined: Feb 2000
Posts: 488
Likes: 28
From: Peabody MA
Re: DFI - Timing at Idle (black bart)
Thanks Bart, I should have dug out the manual before asking. I know that typically running a little less timing at idle helps emissions and general exhaust stink. Currently the car idles around 15-1 according to my wideband but it stinks a little. The cams a healthy size so this is to be expected but I figure I'd try a timing change anyways.
Cam Specs: http://home.attbi.com/~mikeg73/Car/CamCard.jpg
Cam Specs: http://home.attbi.com/~mikeg73/Car/CamCard.jpg
Advanced
Joined: Aug 2001
Posts: 76
Likes: 0
From: Plainfield IL
Re: DFI - Timing at Idle (Mike in Boston)
What I just started progaming the 6.0 dfi computer and I thought it said that chevy base time should be 6 degrees and ford 10 degress. Well lets forget I said ford.
Question 1 is timeing at idle (I mean base timeing) is it every more then 6%(providing your car is warmed up)
Also everyone let me know what you set your base timing to?
Thank you,
Shane
Question 1 is timeing at idle (I mean base timeing) is it every more then 6%(providing your car is warmed up)
Also everyone let me know what you set your base timing to?
Thank you,
Shane
Drifting
Joined: Feb 2002
Posts: 1,952
Likes: 2
From: Little Rock Arkansas
Re: DFI - Timing at Idle (underpressure87)
I've been running the old DFI for almost 10 years... Are you looking for "base" timing or computer map timing at idle? The base on my '90 is set at 10 deg. BTDC and with the EST plugged in and the computer in control it runs at 18-20 at my 950 rpm idle. If you've got a "big" cam and you're running as lean as 15:1 at idle I'm surprised that your car is idling smoothly (if it is)...Big cams tend to like to be a little fatter at idle than stoichiometric (or leaner as is your case)...I'm idling at about 13.5:1 and I have a BIG cam...If I lean it out anymore than that or let it run closed loop at idle it surges and becomes unstable.
-Jeb Burnett
-Jeb Burnett
Advanced
Joined: Aug 2001
Posts: 76
Likes: 0
From: Plainfield IL
Re: DFI - Timing at Idle (jburnett)
Thanks for hte answer.
I believe the car is running ok, but the idle speed flutes between 800-1000 rpm when the car is turned off and the idle speed is set for 800.
by the way its a mild cam the zz9 one on a 383. So I should be able to idle smoothly.
Do you think I have have to modifey the idle spark menu? Which I never did yet.
By the way Jeb what is a EST plugged?
tHANK YOU,
Shane
[Modified by underpressure87, 4:08 AM 4/19/2003]
I believe the car is running ok, but the idle speed flutes between 800-1000 rpm when the car is turned off and the idle speed is set for 800.
by the way its a mild cam the zz9 one on a 383. So I should be able to idle smoothly.
Do you think I have have to modifey the idle spark menu? Which I never did yet.
By the way Jeb what is a EST plugged?
tHANK YOU,
Shane
[Modified by underpressure87, 4:08 AM 4/19/2003]
Drifting
Joined: Feb 2002
Posts: 1,952
Likes: 2
From: Little Rock Arkansas
Re: DFI - Timing at Idle (underpressure87)
The EST circuit is what allows the ECM to control the spark curve; it is pin "C" on the distributor/harness connector...In order to correctly set base timing you need to unplug this; on a stock harness or a piggyback harness there's actually a one wire weatherpack plug in the main harness on the left side of the firewall (near where the brake booster is); on a DFI harness you usually have to actually pull the plug out of the connector.
The ZZ9 is a fairly mild cam and shouldn't require open loop idling...Do you have your closed loop parameters set correctly in "Global?"
-Jeb Burnett
The ZZ9 is a fairly mild cam and shouldn't require open loop idling...Do you have your closed loop parameters set correctly in "Global?"
-Jeb Burnett
