04-25-2005, 10:16 PM | #1 |
Daddy x4 ...we're done
Join Date: Dec 2004
Location: Oxford, AL
Posts: 11,551
|
Why is my timng at idle 13.500 degrees?
After my car has been running and reached operating temperature, my spark at idle holds a very steady advance of 13.500* which seems kind of low to me. It will bump up to around 15* every now and then, but usually returns back.
As I learn different aspects of EEC management, I've been trying to watch my datalogs and see if I can figure out exactly how the computer came up with certain values. This is one of the instances where I just can't figure it out. I have looked at all the functions, scalars, and tables related to spark advance, but I can't find where any combination would pull my spark down that low. What am I missing here? I do know that the EEC will use spark retard to control idle if it can't do it using the IAC, but it doesn't appear that my idle is in bad shape. Also, wouldn't the spark actually be flucuating if it was being used to control engine idle speed?
__________________
-Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring |
04-26-2005, 09:39 AM | #2 |
Im gonna show her my...
Join Date: Dec 2004
Location: Somewhere providing FREE tech support.
Posts: 4,269
|
Re: Why is my timng at idle 13.500 degrees?
Brian, someone on the TwEECer board had the equations of how the EEC calculated final spark. Not that it would specifically answer your question, but I think it would be relevant for this discussion.
Clint, do you have any insight on this because I am coming up empty on the searches.
__________________
I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown |
04-26-2005, 09:54 AM | #3 | |
Daddy x4 ...we're done
Join Date: Dec 2004
Location: Oxford, AL
Posts: 11,551
|
Re: Why is my timng at idle 13.500 degrees?
Quote:
I guess I need to post this thread over there. too.
__________________
-Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring |
|
04-26-2005, 10:08 AM | #4 |
Member
Join Date: Mar 2005
Location: Sacramento California
Posts: 449
|
Re: Why is my timng at idle 13.500 degrees?
If the EEC sees the idle as being to high it will reduce spark. If you are constantly above the desired idle the spark will go down as far as 15. Then if there is multipliers for ACT and ECT the spark could go lower. It seems as if the TB set screw is set to high. The EEC can not control the idle, so it tries the best it can by lowering the spark to its max.
I personally have not looked into the final calculation for the spark. I have not needed to. I just use the three spark tables in the tables section. Keep in mind that FN901 is used under loads defined by FN125. Table FN904a and 905a are used if the load exceeds FN125. You then have to add all of the multipliers and adders.
__________________
EEC Analyzer A9M, TwEECer, 306ci, 73mm C&L w Tuner Tube, Cobra Intake, 42# inj, Edelbrock 6037, E303 cam, 155 fuel pump, FPR, 70mm TB, E-Fan, 3.55 gears, Powerdyne 9psi actual 5psi...way more. |
04-26-2005, 10:20 AM | #5 | |
Daddy x4 ...we're done
Join Date: Dec 2004
Location: Oxford, AL
Posts: 11,551
|
Re: Why is my timng at idle 13.500 degrees?
Quote:
__________________
-Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring |
|
04-26-2005, 11:53 AM | #6 | |
Im gonna show her my...
Join Date: Dec 2004
Location: Somewhere providing FREE tech support.
Posts: 4,269
|
Re: Why is my timng at idle 13.500 degrees?
Quote:
On that subject, what is the correct procedure on setting idle on a fox? Isn't there something like setting the TB screw, turning the A/C on and off, and etc?
__________________
I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown |
|
04-26-2005, 11:59 AM | #7 | |
Daddy x4 ...we're done
Join Date: Dec 2004
Location: Oxford, AL
Posts: 11,551
|
Re: Why is my timng at idle 13.500 degrees?
Quote:
__________________
-Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring |
|
04-26-2005, 12:03 PM | #8 | |
Im gonna show her my...
Join Date: Dec 2004
Location: Somewhere providing FREE tech support.
Posts: 4,269
|
Re: Why is my timng at idle 13.500 degrees?
Quote:
__________________
I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown |
|
04-26-2005, 12:18 PM | #9 |
3v's are slow
Join Date: Dec 2004
Location: Here and There
Posts: 17,152
|
Re: Why is my timng at idle 13.500 degrees?
you can do it with the t/b screw or you can follow the procedure that is in the EEC Analyzer software and use your tweecer off the cobra long enough to data log the IAC duty cycle while setting the idle
__________________
2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy |
|
|