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Topic: What is the best way to set the tps sensor? (Read 4038 times) previous topic - next topic

What is the best way to set the tps sensor?

Reply #30 –
Quote from: Cougar5.0;321213
OK, just to be complete in my investigation, I D/L the 87 Turbocoupe bin AND the 88 Turbocoupe bins and looked at how the TPS is treated.

It's exactly the same as in later years, except the range for closed throttle is 0.72V - 1.33V.

There should be no issue having these above 1V either, unless, as I said above, you turn the screw in while the engine is running, then it might stay in Part Throttle mode until you shut it off and restart it.


This is one that I have to say the specs don't seem to agree with the real world, I've owned 14 TCs and if voltage is above 1v they will probably idle high... May be a glitch in the TC software, as when the idle increases, you won't likely get it to idle down till the engine is shut down and restarted...

What is the best way to set the tps sensor?

Reply #31 –
Quote from: TurboCoupe50;321374
This is one that I have to say the specs don't seem to agree with the real world, I've owned 14 TCs and if voltage is above 1v they will probably idle high... May be a glitch in the TC software, as when the idle increases, you won't likely get it to idle down till the engine is shut down and restarted...


It could be related to the blade being open too far for the ISC motor to control the idle properly. If the car is idling properly and you simply 'adjust' the TPS above 1V while the engine is off, cycle the key off then start the engine, there is no reason it should idle any differently.
11.96 @ 118 MPH old 306 KB; 428W coming soon.

What is the best way to set the tps sensor?

Reply #32 –
all i know is pretty much 100% of the time when people have checked everything and finally arrive at the tps, we tell them to set it back a little and the high idle goes away

for what its worth,, if the eec is just reading from tables and such, then we could just unhook the tps (when the car is running its best) then the eec will have to revert back to last know settings and replicate the voltage swings for the remaining life span of the car....or after 40 warm up cycles it would need hooked back up.

so in one hand those who dont belive in the adjustment are saying we could actually just not run a tps at all....
or did i miss something:D

What is the best way to set the tps sensor?

Reply #33 –
Quote from: jcassity;321452


so in one hand those who dont belive in the adjustment are saying we could actually just not run a tps at all....
or did i miss something:D


I think you missed a whole bunch of somethings :D
Fox-less at the moment

What is the best way to set the tps sensor?

Reply #34 –
Quote from: Cougar5.0;321444
It could be related to the blade being open too far for the ISC motor to control the idle properly. If the car is idling properly and you simply 'adjust' the TPS above 1V while the engine is off, cycle the key off then start the engine, there is no reason it should idle any differently.

I'm not talking about myself making any adjustment prior, just out of the blue there is a high idle condition that will not reduce till engine is shut down and restarted... Upon restart it may be fine for days or idle high at the next stop light, assuring the TPS voltage is less than 1v has fixed the ones I had...

What is the best way to set the tps sensor?

Reply #35 –
So the TPS was above 1V in the first place, then suddenly it would idle high, but just cycling the key or adjusting the TPS lower would 'fix' it? I did notice that the DELTA (part throttle voltage above closed throttle) for the turbocoupe models is 0.07 volts which is higher than most other models - perhaps the "Level C" type TPS unit mentioned in the link in one of the above posts (which was also 'adjustable') has more thermal drift or forms flat/dead spots more easily at idle. I wouldn't be surprised if a 22 year old sensor had some wear.

The fact that the TPS voltage was above 1V before you had an issue supports what I've been saying all along, actually, since the car was running fine before you had an issue. Since cycling the key or moving the TPS position (i.e., when you lower the voltage) changes the wiper position of the TPS, that tends to support the idea of a flat spot forming in the TPS where the wiper might bridge more than one winding and thus put the car in part-throttle mode just from vibration or heat.

Note this picture directly from the Ford manual:



"If the voltage reading on a nonadjustable TPS sensor is not 0.9 - 1.1V at idle, and greater than 4V at WOT, replace throttle position sensor."

Clearly the TPS was intended to be @ 1V +/- 0.1V at idle. It would be unwise to suggest that Ford didn't know how their own engine controls worked.
11.96 @ 118 MPH old 306 KB; 428W coming soon.

What is the best way to set the tps sensor?

Reply #36 –
Quote from: Cougar5.0;321468
TPS where the wiper might bridge more than one winding and thus put the car in part-throttle mode just from vibration or heat.
.


actually, there is no winding.

its a piece of plastic with a carbon strip adhesed to it.
the wiper is a simple brush with a dot of copper / brass / carbon on the end.

i agree though on your theory at idle.  IT would also be a position visited more often than the typical 55/65mph positon where intermittants are experienced.

What is the best way to set the tps sensor?

Reply #37 –
Quote from: hypostang;321455
I think you missed a whole bunch of somethings :D


I was fishin but you dont know me well enough to have picked up on it.:rollin:

Avitar confirmed,,lol

What is the best way to set the tps sensor?

Reply #38 –
Quote from: jcassity;321541
actually, there is no winding.

its a piece of plastic with a carbon strip adhesed to it.
the wiper is a simple brush with a dot of copper / brass / carbon on the end.

i agree though on your theory at idle.  IT would also be a position visited more often than the typical 55/65mph positon where intermittants are experienced.


Ahhh, I was wondering if it was a carbon type or wound. Same thing applies though. Ever see what happens when a carbon type pot gets burnt that controls a DC motor controller? Yikes! Almost blew the top off my airflow chamber when the motor spiked to full on!
11.96 @ 118 MPH old 306 KB; 428W coming soon.