docraymund
Full Access Members
Going back to your original post, if your truck seems to be struggling while going uphill but is not misfiring, I think you are right in suspecting a bad torque converter. Try inspecting it.
The dreaded throttle position sensor
- Thread starter and0r
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
stamp11127
Full Access Members
I'm always looking for new things to learn. So how is he going to inspect a sealed torque converter? And how does the tc control line pressure and shift points?
FORscan is pretty in depth. It reports each individual module, such as GEM, ABS, OBD, PCM, IC, and a few others. I didn't see anything about a transmissions though, would that be part of the TCM module? Either way, the PCM is not showing any codes.
I would recommend that everybody here use Forscan and a BAFX OBD2 reader from ebay.
Or you can pick up a VXDIAG unit on ebay too for about 90$. It comes with "registered" Ford IDS software. This is full-on factory level diagnostics, including firmware flashing. (You need to provide the firmware though)
Anyway, I got the idea to cut away a slot in the stripped TPS mounting screw with a rotary tool with cut-off wheel, so I can unscrew the new slot with a flathead screwdriver. I'm probably going to try doing this tomorrow. And I have a quality set of extractor bits to fall back on in case it doesn't work.
Worse case scenario I have to pick up a new throttle-body.
Mine looks very clean by the way. The more I explore on this truck, the more evidence I find of the miles being totally original, which makes me very happy!
Does anyone know where to get these mounting screws for the TPS?
I would recommend that everybody here use Forscan and a BAFX OBD2 reader from ebay.
Or you can pick up a VXDIAG unit on ebay too for about 90$. It comes with "registered" Ford IDS software. This is full-on factory level diagnostics, including firmware flashing. (You need to provide the firmware though)
Anyway, I got the idea to cut away a slot in the stripped TPS mounting screw with a rotary tool with cut-off wheel, so I can unscrew the new slot with a flathead screwdriver. I'm probably going to try doing this tomorrow. And I have a quality set of extractor bits to fall back on in case it doesn't work.
Worse case scenario I have to pick up a new throttle-body.
Mine looks very clean by the way. The more I explore on this truck, the more evidence I find of the miles being totally original, which makes me very happy!
Does anyone know where to get these mounting screws for the TPS?
Last edited:
stamp11127
Full Access Members
Apply heat to the bolt and come back with a small portable impact or you will mess the slot up. Use just a few wacks from the impact to see if it moves.
Success!
But the degree of success remains unclear.
First off, I was barely able to break the screw free after cutting a slot all the way down, just a micro meter away from the base, and using the largest flathead screwdriver I had. I put all my strength into it, much more than I thought I had, and it finally broke free. I meant to take pictures of everything, but I was just totally determined to get my truck running again, so I just threw everything back together without taking pics.
I reused the screw since none of you will actually tell me where to get another one, it works fine. And I greased the screws with penetrating oil before they went it.
The first thing I noticed when taking her for the first testdrive was the transmission. Each gear was shifting perfect, better than it was before, even the 2-3 upshift was smooth as butter, and it had always been a little harsh before the TPS failure.
Launching the truck from a standstill was also good and consistent.. The torque was nice and girthy, I couldn't reproduce the flaccid, weak launches. Which is good.
Then I took her up a steep hill, to Mullholland HYW, which is paved, and her power was still not as strong as I liked. But was slightly better than before. I must have drove her around for 30 miles, testing all gears and just listening to the truck.
I noticed that after getting back down the hill to my street, the standstill launches were getting weak again, but the shifting was still good.
I think I know why these sensors fail. It's the heat.
I checked the throttle-body in my garage with the engine still running and it was damn hot. Everything was hot. It's a big engine.
I touched the sensor and it was damn hot too. It didn't burn me, but it was hot enough to immediately understand this temperature not being good for the plastic components of the sensor.
I'm thinking of wiring a nice, high-RPM PC fan and maybe even a heatsink directly to the sensor! I have plenty of spare fans and heatsinks lying around.
What do you guys think?
The temp is clearly too much for the sensor in my opinion.
But the degree of success remains unclear.
First off, I was barely able to break the screw free after cutting a slot all the way down, just a micro meter away from the base, and using the largest flathead screwdriver I had. I put all my strength into it, much more than I thought I had, and it finally broke free. I meant to take pictures of everything, but I was just totally determined to get my truck running again, so I just threw everything back together without taking pics.
I reused the screw since none of you will actually tell me where to get another one, it works fine. And I greased the screws with penetrating oil before they went it.
The first thing I noticed when taking her for the first testdrive was the transmission. Each gear was shifting perfect, better than it was before, even the 2-3 upshift was smooth as butter, and it had always been a little harsh before the TPS failure.
Launching the truck from a standstill was also good and consistent.. The torque was nice and girthy, I couldn't reproduce the flaccid, weak launches. Which is good.
Then I took her up a steep hill, to Mullholland HYW, which is paved, and her power was still not as strong as I liked. But was slightly better than before. I must have drove her around for 30 miles, testing all gears and just listening to the truck.
I noticed that after getting back down the hill to my street, the standstill launches were getting weak again, but the shifting was still good.
I think I know why these sensors fail. It's the heat.
I checked the throttle-body in my garage with the engine still running and it was damn hot. Everything was hot. It's a big engine.
I touched the sensor and it was damn hot too. It didn't burn me, but it was hot enough to immediately understand this temperature not being good for the plastic components of the sensor.
I'm thinking of wiring a nice, high-RPM PC fan and maybe even a heatsink directly to the sensor! I have plenty of spare fans and heatsinks lying around.
What do you guys think?
The temp is clearly too much for the sensor in my opinion.
Last edited:
Dewayne
Well-Known Member
As long as you installed a quality part you should be fine , I have seen too many people add unnecessary devices to their vehicle and cause problems . Had a guy install a high intensity fog light system in his truck once and wire it to the fuel pump circuit truck would run like crap under load with lights on .
I would look into wiring any 12v fan on the ignition circuit.
The engine is just way too damn hot for the sensor. Top half is all aluminum, the heads and intake. It sinks the heat from the iron block pretty niceley. The iron is very hard to cool compared to aluminum.
This sensor is just chintzy plastic with a variable resistor of some sort inside. At some point the heat must also directly effect the resistence on top of weakening any plastic housing or smaller plastic components. Heat plays a direct role in electrical resistence too. I'm tempted to cut open the old TPS sensor and look inside.
Which way should I cut it?
The engine is just way too damn hot for the sensor. Top half is all aluminum, the heads and intake. It sinks the heat from the iron block pretty niceley. The iron is very hard to cool compared to aluminum.
This sensor is just chintzy plastic with a variable resistor of some sort inside. At some point the heat must also directly effect the resistence on top of weakening any plastic housing or smaller plastic components. Heat plays a direct role in electrical resistence too. I'm tempted to cut open the old TPS sensor and look inside.
Which way should I cut it?
It's a little silly that Ford would just throw this sensor directly on a heated aluminum component this way. I don't think a PC fan will cut it either.
Probably need to throw on a small CPU water block cooler, like the ones for gaming computers.
Probably need to throw on a small CPU water block cooler, like the ones for gaming computers.
Big Brian
Full Access Members
just use a Motorcraft or other quality sensor
you know they test these things. Heat is not a foreign matter in a engine compartment
In the test lab where I work we test engine and water pumps and other under the hood components at 140c for months at at time
lets just think about this
you have a 99. Its most likely the original tps
the original tps lasted 18 years. You said in a previous post you were 18.
So it is as old as you are
seems to me like a reasonable service life
you know they test these things. Heat is not a foreign matter in a engine compartment
In the test lab where I work we test engine and water pumps and other under the hood components at 140c for months at at time
lets just think about this
you have a 99. Its most likely the original tps
the original tps lasted 18 years. You said in a previous post you were 18.
So it is as old as you are
seems to me like a reasonable service life
Last edited:
I said I was 19
And has anyone tested the signal of the TPS under the heat from driving around the city on a hot day? While actually driving.
Probably reads incorrect.
Just because something "works" for 18 years, doesn't mean it's working properly.
This could very well be a common and overlooked flaw within this system.
You need to be a little more sceptic!
And has anyone tested the signal of the TPS under the heat from driving around the city on a hot day? While actually driving.
Probably reads incorrect.
Just because something "works" for 18 years, doesn't mean it's working properly.
This could very well be a common and overlooked flaw within this system.
You need to be a little more sceptic!
Big Brian
Full Access Members
nothing changes with you
what was overlooked? the sensor lasted 18 years lol
I dont know why I bother looking at your threads.
hope things at NASA are going well for you
what was overlooked? the sensor lasted 18 years lol
I dont know why I bother looking at your threads.
hope things at NASA are going well for you
Last edited:
Big Brian
Full Access Members
I am trying to talk to someone who said he works for NASA, his profile says he is 35 but in fact he is 19.
does he even own an Expedition?
Is he an internet troll?
yes its a sad world my friend
my point is you have an 18 year old sensor that went bad just live with it dude
does he even own an Expedition?
Is he an internet troll?
yes its a sad world my friend
my point is you have an 18 year old sensor that went bad just live with it dude
Big Brian
Full Access Members
just to add
I have plenty of experience and useful information since I work in the automotive industry
thats all I am trying to add. If you dont see the value in it I know others do
I have plenty of experience and useful information since I work in the automotive industry
thats all I am trying to add. If you dont see the value in it I know others do
this was said - that was said; seems like you are focusing too much on a very simple comment, which was clearly not meant to be taken literally.
idk why my profile says im 25 though
where can i get mounting screws for the TPS?
idk why my profile says im 25 though
where can i get mounting screws for the TPS?
Dewayne
Well-Known Member
Ford would be my first choice, Fastenal would be my second choice , junk yard last resort - they probably make you buy the entire throttle body .
Cool.
Also I checked the throttle body temp again, and it actually is burning to the touch, I probably should hit it with the laser temp reader to get an exact reading.
This can't be good for the TPS
