Probable Error in a 'Setting the TPS' thread
03-21-2008, 04:11 AM
#21
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RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: roush32
Go out to your fox and set your TPS on the low end, ie . .80 volts, let us know how it works out
.
Go out to your fox and set your TPS on the low end, ie . .80 volts, let us know how it works out
.
I already have done this...
Trying to get my 408w to idle a little better, I tried all the usual junk...
set tps to .9998v (it was down around .85 IIRC)
Set fuel pressure to 38.9psi (or whatever value your local magazine expert decides to spew that day...)
It's all crap, and once you start looking at the way the ecu works you will start to understand that.....
Please,
Offer up some reason/justification/explanation for what you are claiming...
HOW does .99v allow the ecu to provide better throttle response.
Your data doesn't match my data...
Let's try to figure out why...
Just for giggles, I'll post this again in this thread...
Here are a couple of excerpts from the GUFB (the book Ford ecu programmers used when programming the Fox ecu)
http://www.fordfuelinjection.com/files/GUFB.pdf
The logic described below considers the current position of the throttle
and compares its value to the RATCH, Closed Throttle, plus the change in
throttle position from the last setting. If both flip-flops in the logic
clear, then Part Throttle is set.
OVERVIEW
The throttle mode scheduler is used to determine what engine operating
region is currently extant. The variable APT (At Part Throttle flag) is used
to indicate throttle mode and is assigned the following values:
Throttle Mode APT
------------------ ---
CLOSED THROTTLE -1
PART THROTTLE 0
WIDE OPEN THROTTLE 1
The value of APT is determined by the logic shown on the following page.
Briefly, throttle angle breakpoints, in terms of counts, are used to define
the CLOSED/PART_THROTTLE and PART/WIDE_OPEN_THROTTLE transitions. Hysteresis
is incorporated in both breakpoints to prevent jitter between modes.
The variable RATCH is the output of a ratchet algorithm which continuously
seeks the minimum throttle angle corresponding to a CLOSED THROTTLE position.
This alleviates the necessity to set the throttle position sensor at an
absolute position and compensates for system changes and differences between
vehicles. The ratchet algorithm uses filtered throttle position for the
determination of RATCH.
A more detailed explanation of the throttle position ratchets and throttle
position filter is contained in the SYSTEM EQUATIONS section.
DEFINITIONS
INPUTS
Registers:
- APT = Status of Part Throttle. (Set = -1 = Closed Throttle) (Set = 1 =
Wide Open Throttle) (Set = 0 = Part Throttle)
- RATCH = Closed throttle.
- TP = Position of Throttle.
INPUTS
Registers:
- APT = Status of Part Throttle. (Set = -1 = Closed Throttle) (Set = 1 =
Wide Open Throttle) (Set = 0 = Part Throttle)
- RATCH = Closed throttle.
- TP = Position of Throttle.
The logic described below considers the current position of the throttle
and compares its value to the RATCH, Closed Throttle, plus the change in
throttle position from the last setting. If both flip-flops in the logic
clear, then Part Throttle is set.
PROCESS
TP <OR= RATCH + DELTA ---------------|S Q -| Closed Throttle mode
| | APT = -1
TP <OR= RATCH + DELTA + HYST2 ------|C |
| --- ELSE ---
|
|
TP > (RATCH+THBP2+HYST2) -|S Q ------------| Wide Open Throttle
| | mode
TP <OR= (RATCH + THBP2) --|C | APT = 1
|
| --- ELSE ---
|
| Part Throttle Mode
| APT = 0
NOTE: PTSCR is initialized to 0.
previous APT = -1 ------------|
|
current APT NOT= -1 ----------|AND ---------| Set CTPTFG = 1
| | Closed Throttle to
CRKFLG = 1 -------------------| | Part Throttle transition
|
| --- ELSE ---
previous APT = -1 ------------| |
| |
current APT NOT= -1 ----------|AND ---------| Set CTPTFG = 1
| | Closed Throttle to
CRKFLG = 0 -------------------| | Part Throttle transition
| Set PTSCR = 1
|
| --- ELSE ---
|
| Set CTPTFG = 0
and compares its value to the RATCH, Closed Throttle, plus the change in
throttle position from the last setting. If both flip-flops in the logic
clear, then Part Throttle is set.
PROCESS
TP <OR= RATCH + DELTA ---------------|S Q -| Closed Throttle mode
| | APT = -1
TP <OR= RATCH + DELTA + HYST2 ------|C |
| --- ELSE ---
|
|
TP > (RATCH+THBP2+HYST2) -|S Q ------------| Wide Open Throttle
| | mode
TP <OR= (RATCH + THBP2) --|C | APT = 1
|
| --- ELSE ---
|
| Part Throttle Mode
| APT = 0
NOTE: PTSCR is initialized to 0.
previous APT = -1 ------------|
|
current APT NOT= -1 ----------|AND ---------| Set CTPTFG = 1
| | Closed Throttle to
CRKFLG = 1 -------------------| | Part Throttle transition
|
| --- ELSE ---
previous APT = -1 ------------| |
| |
current APT NOT= -1 ----------|AND ---------| Set CTPTFG = 1
| | Closed Throttle to
CRKFLG = 0 -------------------| | Part Throttle transition
| Set PTSCR = 1
|
| --- ELSE ---
|
| Set CTPTFG = 0
(to find this info for yourself, just open the pdf file, and do a search for the term 'RATCH')
03-21-2008, 08:52 AM
#22
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Join Date: Jan 2008
Location: Pennsylvania
Posts: 580
RE: Probable Error in a 'Setting the TPS' thread
what?....... I will send you a pdf that FORD sent me, if u like.
BUT guaranteed that 90% of the mustang out there idle like crap bc this "procedure" is overlooked..... and part of this procedure is setting your tps.
BUT guaranteed that 90% of the mustang out there idle like crap bc this "procedure" is overlooked..... and part of this procedure is setting your tps.
03-21-2008, 01:04 PM
#25
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Join Date: Jan 2006
Location: Puerto Rico
Posts: 3,926
RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: Jasperstang308
joel and jason it appears your speaking to deaf ears
joel and jason it appears your speaking to deaf ears
And a little more FYI on the subject is shown below, not hearsay, not undocumented arguments....... the official tech procedure for the TPS adjustment + an extract of the TPS logic used in every EEC-IV (OBD-I) and included in the EEC-V (OBD-II) logic as well.
Do you know what FoMoCo stands for?....... now look at the explanation of the variable RATCH....... if the system automatically resets itself to the lowest value, and uses +.04 vdc from the minimum to switch APT value from closed throttle to part throttle, and +2.71 vdc from the minimum to switch it to WOT...... why would a .999999 value be so important? ....... is there an alternate "Performance algorithm" when the TP is set at that mythical value?.......
03-21-2008, 01:39 PM
#26
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Thread Starter
Join Date: Nov 2007
Location: Washington, Seattle
Posts: 551
RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: cholericfc
what?....... I will send you a pdf that FORD sent me, if u like.
what?....... I will send you a pdf that FORD sent me, if u like.
But, if it is the document I am thinking of... it is vague, and leaves things open to impression... AND there was a date on it that left me wondering if it was written for EEC-III or EEC-IV....
Still, if you pm me, I'll send you my email. I wouldn't mind hosting it on my site so that I can link to it here
ORIGINAL: cholericfc
BUT........ you guys are "BUILT TOUGH," and are always right.......
BUT........ you guys are "BUILT TOUGH," and are always right.......
I have been wrong WAY more than I have been right [:@]
jason
03-21-2008, 06:54 PM
#27
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Join Date: Mar 2008
Location:
Posts: 153
RE: Probable Error in a 'Setting the TPS' thread
The reason the proceedure in the shop manual says to realign reference marks is so the keep alive memory doesn't have to be reset. The PCM remembers the lowest voltage(within a few tenths of 1.0v) as "closed throttle". This is used as logic toward IAC operation. At idle I just need to vary the valve enough to maintain a specific RPM right? At voltages slightly higher than 1.0v it sees "part throttle" mode and then switches the logic toward dashpot (slow, controlled deceleration under closed throttle)and thus the IAC remains more open and quick to respond inchanges in engine speed. This is why you can change the speed of your engine without moving the throttle plate. It can't speed up without getting more air and if it aint coming from the throttle body its coming from somewhere else.
Anyhow - if you plug in a new TP without resetting the memory of the computer and that "new" TP voltage is several tenths of a volt HIGHER than the last one - the computer says "Hey, I'm at part throttle. I'm gonna work the IAC like I'm accelerating".
Disconnecting the battery for 20-40 minutes should reset everything and relearn everything within a few drive cycles. EECIV is pretty basic and forgiving when it comes to signals out of range or missing all together. You can fiddle *** around with the TP all day long and the most you will do is change your idle speed (likely for the worse) and mayyybe make it just a tad more crisp on tip in and that's only because your idling at 1000 rpm. Disconnect your battery overnight and you will find that your magic setting is gone and was all in your head to begin with.
Anyhow - if you plug in a new TP without resetting the memory of the computer and that "new" TP voltage is several tenths of a volt HIGHER than the last one - the computer says "Hey, I'm at part throttle. I'm gonna work the IAC like I'm accelerating".
Disconnecting the battery for 20-40 minutes should reset everything and relearn everything within a few drive cycles. EECIV is pretty basic and forgiving when it comes to signals out of range or missing all together. You can fiddle *** around with the TP all day long and the most you will do is change your idle speed (likely for the worse) and mayyybe make it just a tad more crisp on tip in and that's only because your idling at 1000 rpm. Disconnect your battery overnight and you will find that your magic setting is gone and was all in your head to begin with.
03-22-2008, 10:01 PM
#28
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Thread Starter
Join Date: Nov 2007
Location: Washington, Seattle
Posts: 551
RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: dudeboy
PLEASE shoot me a pm with this document... I would love to read it.
ORIGINAL: cholericfc
what?....... I will send you a pdf that FORD sent me, if u like.
what?....... I will send you a pdf that FORD sent me, if u like.
03-22-2008, 10:28 PM
#29
5th Gear Member
Join Date: Jan 2006
Location: Puerto Rico
Posts: 3,926
RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: 1990lxhatch
The reason the proceedure in the shop manual says to realign reference marks is so the keep alive memory doesn't have to be reset. The PCM remembers the lowest voltage(within a few tenths of 1.0v) as "closed throttle". This is used as logic toward IAC operation. At idle I just need to vary the valve enough to maintain a specific RPM right? At voltages slightly higher than 1.0v it sees "part throttle" mode and then switches the logic toward dashpot (slow, controlled deceleration under closed throttle)and thus the IAC remains more open and quick to respond inchanges in engine speed. This is why you can change the speed of your engine without moving the throttle plate. It can't speed up without getting more air and if it aint coming from the throttle body its coming from somewhere else.
Anyhow - if you plug in a new TP without resetting the memory of the computer and that "new" TP voltage is several tenths of a volt HIGHER than the last one - the computer says "Hey, I'm at part throttle. I'm gonna work the IAC like I'm accelerating".
Disconnecting the battery for 20-40 minutes should reset everything and relearn everything within a few drive cycles. EECIV is pretty basic and forgiving when it comes to signals out of range or missing all together. You can fiddle *** around with the TP all day long and the most you will do is change your idle speed (likely for the worse) and mayyybe make it just a tad more crisp on tip in and that's only because your idling at 1000 rpm. Disconnect your battery overnight and you will find that your magic setting is gone and was all in your head to begin with.
The reason the proceedure in the shop manual says to realign reference marks is so the keep alive memory doesn't have to be reset. The PCM remembers the lowest voltage(within a few tenths of 1.0v) as "closed throttle". This is used as logic toward IAC operation. At idle I just need to vary the valve enough to maintain a specific RPM right? At voltages slightly higher than 1.0v it sees "part throttle" mode and then switches the logic toward dashpot (slow, controlled deceleration under closed throttle)and thus the IAC remains more open and quick to respond inchanges in engine speed. This is why you can change the speed of your engine without moving the throttle plate. It can't speed up without getting more air and if it aint coming from the throttle body its coming from somewhere else.
Anyhow - if you plug in a new TP without resetting the memory of the computer and that "new" TP voltage is several tenths of a volt HIGHER than the last one - the computer says "Hey, I'm at part throttle. I'm gonna work the IAC like I'm accelerating".
Disconnecting the battery for 20-40 minutes should reset everything and relearn everything within a few drive cycles. EECIV is pretty basic and forgiving when it comes to signals out of range or missing all together. You can fiddle *** around with the TP all day long and the most you will do is change your idle speed (likely for the worse) and mayyybe make it just a tad more crisp on tip in and that's only because your idling at 1000 rpm. Disconnect your battery overnight and you will find that your magic setting is gone and was all in your head to begin with.
03-22-2008, 10:34 PM
#30
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Join Date: Jan 2006
Location: Puerto Rico
Posts: 3,926
RE: Probable Error in a 'Setting the TPS' thread
ORIGINAL: dudeboy
I would sincerely like to see this pdf you have
ORIGINAL: dudeboy
PLEASE shoot me a pm with this document... I would love to read it.
ORIGINAL: cholericfc
what?....... I will send you a pdf that FORD sent me, if u like.
what?....... I will send you a pdf that FORD sent me, if u like.
