Checking TPS Voltage?

[b58tt]

I've got a voltmeter that I can use. How do I go about checking the TPS sensor?

 

[Roland69]

To set your TPS you will need a couple basic hand tools:



1. A Phillips head screw driver

2. A digital multi-meter

3. A drill & small drill bit (If this is your first time adjusting it)


Procedure:

--------------------------------------------------------------------------------

Throttle Position Sensor adjustment is a very basic but often asked question. The benefits of resetting the TPS is as follows:



1. Increased throttle response

2. Smoother idle (when you are lean at idle)

3. Can be used to compensate for a rich or lean idle

4. EEC will reach wide open throttle operation sooner resulting in faster acceleration


To locate the sensor open the hood & look towards your passenger side strut tower. Locate the throttle body attached to the intake & the sensor attached to the top of it. This is the TPS Sensor, two Philips head screws hold it down. To adjust it you will to have your ignition on but not with the car running, this will energize the EEC & the sensors. To check the setting as it is you will need to use a digital multi-meter, & some basic wiring knowledge. The Black wire is your ground the orange is your 5 volt reference wire & the green is the EEC feed wire. Probe the green wire with the positive lead & the black lead to the black wire. You may see readings from the mid .70v up to 1.0+v, the range that it is typically set at is .95-1.00v.

Loosen the top two screws & turn it clockwise or counter clockwise until you get it in the specified voltage range. If you cannot get it into adjustment as it is you will need to remove the sensor from the car. Once removed from the car use the small drill bit to elongate the holes in a crescent shape. Reattach it to the vehicle, & adjust it until it reads Between .95-.97v . Tighten down the two screws & turn off the key. You do not need to reset the EEC, as it is really not necessary.

 

[b58tt]

How do I "probe" the wires? lol.

 

[Mavrick]

Two sewing needles work good, then you can use them as contacts for the multimeter.

 

[b58tt]

Yeah I know, but I'm not sure what I should set my multimeter too. Where do I stick the positive and negative?

 

[bill302]

stick each (2) wire with a sewing needle and check voltage at the needle and when you remove needle wipe some waterproof sealant over needle hole form-a gasket sealant or equivalent will work....

 

[Mavrick]

Stick a needle in the black wire, and another needle in the green wire (coming out of the TPS). Your positive (red) lead should be held onto the needle coming out of the green wire, and the negative (black) lead should be held onto the needle sticking out of the black wire. Then you select volts on your multimeter (whichever volts option that will give you two decimal places after the decimal), and this should give you a reading.

 

[stang&2Birds]

Throttle Position Sensor adjustment is a very basic but often asked question. The benefits of resetting the TPS is as follows:


1. Increased throttle response

2. Smoother idle (when you are lean at idle)

3. Can be used to compensate for a rich or lean idle

4. EEC will reach wide open throttle operation sooner resulting in faster acceleration

BTW: That's PURE AND TOTAL BS!!!!!!!!
NONE, I repeat, NONE OF THAT IS EVEN CLOSE TO BEING TRUE!

Here is MY TPS tech article:
http://www.veryuseful.com/mustang/tech/engine/Mustang-TPS-FAQ.html

BTW: I taught this stuff and do this type of stuff for a living!
I've also read the EEC assembler code and the Ford Documents.

 

[vristang]

BTW: That's PURE AND TOTAL BS!!!!!!!!
NONE, I repeat, NONE OF THAT IS EVEN CLOSE TO BEING TRUE!

Here is MY TPS tech article:
http://www.veryuseful.com/mustang/tech/engine/Mustang-TPS-FAQ.html

BTW: I taught this stuff and do this type of stuff for a living!
I've also read the EEC assembler code and the Ford Documents.

I thought the the comments on triggering of WOT made sense, though I see the affect as being minimal.

I have read parts of the GUFB doc, but not all 1,700 pages.
Mad props given, Yo!

I hope this doesn't turn into a pissing contest, because I am curious to hear how a good debate will go on this subject.

:SNSign:

jason

 

[stang&2Birds]

have read parts of the GUFB doc, but not all 1,700 pages.

GUFB is "only" 591 pages. The newer strategies are over 1000 pages.

ELECTRONIC FUEL INJECTION (SFI-MA) STRATEGY BOOK
STRATEGY LEVEL "GUFB"
NOTE: OVER 16K; REQUIRES 2732 CHIPS
FOR USE WITH EEC-IV MODULES: SFI-MA1, SFI-MA2 AND SFI-MA3
is 591 pages in PDF form.

I thought the the comments on triggering of WOT made sense, though I see the affect as being minimal.

Nope. For the A(L, and most Fox stangs, WOT is 2.7v above the startup voltage of the TPS. I'm pretty sure that was even in
TECHNICAL NOTES ON THE EEC-IV MCU
Compiled by Tom Cloud

I think that parameter was also in Mike Wesley's orig EEC "custom chip" software. "Somewhere" I have his orig software that he made public.

I hope this doesn't turn into a pissing contest, because I am curious to hear how a good debate will go on this subject.

Can't. It's WELL know on the tweecer/EEC-tuner/ect boards. Plus, it's in GUFB spec and the EEC assembler code. If someone else has also written code for the EEC (I'm not talking about using a Tweecer), then I'll talk to them. Otherwise, they can read MY article and "talk to the hand" if they disagree.

 

[stang&2Birds]

Found it in Tom Cloud's doc:
WOT TPS value
Table 18: EEC Scalars

 

[stang&2Birds]

From:
ELECTRONIC FUEL INJECTION (SFI-MA) STRATEGY BOOK
STRATEGY LEVEL "GUFB"
NOTE: OVER 16K; REQUIRES 2732 CHIPS
FOR USE WITH EEC-IV MODULES: SFI-MA1, SFI-MA2 AND SFI-MA3


From Chapter 5-2:
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.



From Chapter 19-9:
(Where the RATCH output is defined)
- RATCH = Lowest filtered throttle position, counts.




From Chapter 19-43:
INPUT CONVERSIONS AND FILTERS - GUA0
PEDD-PTOPE, FoMoCo, PROPRIETARY & CONFIDENTIAL
THROTTLE POSITION RATCHET (RATCH)
The throttle position ratchet (RATCH) continuously seeks a lower value for
both throttle angle breakpoints, CLOSED THROTTLE/PART THROTTLE and PART
THROTTLE/WOT, by seeking the lowest filtered throttle angle (TPBAR). The
algorithm is not used during CRANK mode.
CRKFLG = 0 -----------------|
| | RATCH = TPBAR
TPBAR <OR= RATCH -----------|AND -----|
| | --- ELSE ---
N > 450 RPM ----------------| |
| NO CHANGE TO RATCH

 

[vristang]

GUFB is "only" 591 pages. The newer strategies are over 1000 pages.

ELECTRONIC FUEL INJECTION (SFI-MA) STRATEGY BOOK
STRATEGY LEVEL "GUFB"
NOTE: OVER 16K; REQUIRES 2732 CHIPS
FOR USE WITH EEC-IV MODULES: SFI-MA1, SFI-MA2 AND SFI-MA3
is 591 pages in PDF form.




Nope. For the A(L, and most Fox stangs, WOT is 2.7v above the startup voltage of the TPS. I'm pretty sure that was even in
TECHNICAL NOTES ON THE EEC-IV MCU
Compiled by Tom Cloud

I think that parameter was also in Mike Wesley's orig EEC "custom chip" software. "Somewhere" I have his orig software that he made public.



Can't. It's WELL know on the tweecer/EEC-tuner/ect boards. Plus, it's in GUFB spec and the EEC assembler code. If someone else has also written code for the EEC (I'm not talking about using a Tweecer), then I'll talk to them. Otherwise, they can read MY article and "talk to the hand" if they disagree.

I remember that the 2.7v for wot is adjusted for the base setting. Brain fart I guess.

I converted the GUFB to a Word doc, so I could reformat things a little. It came out to 1700pgs in Word.

Could you post a link to the article you mention, and the Tom Cloud doc?

I completely understand your above comment on the tweecer, it has its limitations.
Do you have any software recommendations in place of CalEdit?
I have been told that PCMX is about as good as it gets. Those I have spoken to using PCMX still use the tweecer, but only for datalogging.

thanks for taking the time to address my question/comments, even though I had just forgotten the right answer.

jason

 

[vristang]

From:
ELECTRONIC FUEL INJECTION (SFI-MA) STRATEGY BOOK
STRATEGY LEVEL "GUFB"
NOTE: OVER 16K; REQUIRES 2732 CHIPS
FOR USE WITH EEC-IV MODULES: SFI-MA1, SFI-MA2 AND SFI-MA3



From Chapter 19-43:
INPUT CONVERSIONS AND FILTERS - GUA0
PEDD-PTOPE, FoMoCo, PROPRIETARY & CONFIDENTIAL
THROTTLE POSITION RATCHET (RATCH)
The throttle position ratchet (RATCH) continuously seeks a lower value for
both throttle angle breakpoints, CLOSED THROTTLE/PART THROTTLE and PART
THROTTLE/WOT, by seeking the lowest filtered throttle angle (TPBAR). The
algorithm is not used during CRANK mode.
CRKFLG = 0 -----------------|
| | RATCH = TPBAR
TPBAR <OR= RATCH -----------|AND -----|
| | --- ELSE ---
N > 450 RPM ----------------| |
| NO CHANGE TO RATCH

Can you clarify "continuously seeks a lower value"?

I was under the assumption that the base tps was taken just after start-up, and did not change while the engine was running.
According to the GUFB, RATCH is trying to reset constantly when ever the engine is running?
Maybe I misunderstood that?

thanks
jason

 

[HISSIN50]

I don't pretend to know that much about the TPS (I don't want to) but I thought it did continuously check for baseline values (otherwise cranking while at WOT could create some issues, for instance).

I don't mean to come off confrontational (this is a much friendlier, respectful forum IMHO than some of the others ), but if idle surging wasnt programmed by design, and some folks swear by farting around with the static TPS reading (it's free, so why not), what's the harm?

 

[stang&2Birds]

ICould you post a link to the article you mention, and the Tom Cloud doc?

It should be on the "yahoo" site.

Also, you can find it by searching for "Tom Cloud"

or

EEC IV Technical Documentation, from allfordmustangs.com
A most read guide to the inner workings of the EEC IV PCM.
http://www.allfordmustangs.com/techarticles/EECIV_Technical_Doc.zip

 

[stang&2Birds]

I was under the assumption that the base tps was taken just after start-up, and did not change while the engine was running.
According to the GUFB, RATCH is trying to reset constantly when ever the engine is running?

I don't pretend to know that much about the TPS (I don't want to) but I thought it did continuously check for baseline values (otherwise cranking while at WOT could create some issues, for instance).

Yes, RATCH is re-adjusted as the engine runs. But, there is smoothing on the board before the EEC CPU, and there is a smoothing function in GFUB. It's often said "base line set at start-up" because it gets very involved to go into the MANY details.

Like, the FMEM checking for the TPS and how the TPS can be "disabled" while the car is running. Things are often said in "simpler terms".

 

[stang&2Birds]

I don't mean to come off confrontational (this is a much friendlier, respectful forum IMHO than some of the others ), but if idle surging wasn't programmed by design, and some folks swear by farting around with the static TPS reading (it's free, so why not), what's the harm?

[on soapbox]
Because it was *not* the adjusting of the TPS that fixed the surging. People strip the bolt holes, spend money, and waste time screwing around doing stupid things. THEN, they spread their BS to others. And, other people GET SCREWED from the BAD information.

There's a TON of things that can cause surging and that can make the "surging go away". However, screwing around with the TPS is not one of them.

*I* care about telling people THE TRUTH and stopping the BS MYTHs. If YOU go around telling people that adding a 12-foot wing helped you to reduce your qtr mile time by 1 second, then you know what? You look "FOOLISH/Stupid" to the people that know better. Do YOU want to look "FOOLISH/Stupid"? I know that *I* don't. So, *I* get PO'd when other people give me bad information. and then *I* go on to tell that BS to others.

Yes, *I* do make mistakes. EVERYONE DOES! But, spreading KNOWN BS is WRONG - Period!

I've mentioned before that I taught (EE/CS) for 8 semesters. A GOOD teacher will always tell people the "best possible" knowledge they know and they will NOT spread BS. Of course, as new things are learned over time, and we find out that old *beliefs* were, in fact, wrong. But, that is VERY DIFFERENT that PURPOSELY spreading BS!
[off soapbox]



BTW: I think that because I used to teach, and I still mentor younger engineers (I've been a Principal Engineer / System Architect for over 10 years), trying to be as accurate as possible is important to me.

 

[stang&2Birds]

BTW: I've said this a ton of times.
For "100%" stock setups with surging problems
1) Read the codes
2) Put on a new *Ford* IAB/IAC
3) Put on a new *Ford* EGR.

THEN, you start to look at other things.

For people with a cone air filter on the end of the MAF, engine bay air filter, C&L, or ProM 75mm, then sorry that's your problem! *I* didn't tell you to get any of those!

 

[stang&2Birds]

Those I have spoken to using PCMX still use the tweecer, but only for datalogging.

The tweecer is nice for datalogging because of the support for the log files.

Before, I also used the EEC Tunner for data logging. Also, I have used own custom EEC software and hardware to do data logging. A "few" of us hardware engineers did that back in the 90's. But, it's like the difference between a MAC and a PC. The software support makes a huge difference.

I do have more advanced custom data logging stuff now. But, thanks to the GFUB document, I don't spend time reverse engineering to try to figure out stuff. Plus, since I don't have a blower, there's not much need for me to do a lot of screwing around.