Tps still a problem

[CDW6212R]

Are you sure the TPS is going into the TB properly? I'm not presuming you did it wrong, I just can't think of what other odd thing would cause a wild change like that. The TPS can go on two ways interlocking with the odd shape of the TB shaft. One way will have resistance on the TPS sensor, and the proper voltage curve. The other way doesn't alter the voltage curve much at all. It's hard to describe, but playing with how it goes together usually explains it. If you aren't sure, go back and pull the TPS, and slowly reinstall it.

 

[bigred4x4]

I've tried everything in different ways to install it and hopefully getting a different outcome I found only one way to put it on as it'll only turn 1/4 turn then stop and it will not turn the opposite way. I took the plug apart hoping to find a bad terminal but still nothing even double checked the crimp connectors, I'm stumped other than tracing every bit of wiring ..... Intake plenum and entire wiring harness would have to come undone or check the PCM some how I'm hoping I didn't fry a PCM capacitor when I switched the signal and ground wire ( I'm getting the same voltage readings with new sensor and plug with the wires connected properly now as I was when I thought they were wired wrong and switched the signal and ground ) . I've tried resetting the PCM because I read of a pull down capacitor to throw a code and that didn't work the resistance in the wires seem to check out I tell ya this is turning into a real head scratcher wish I had a fancy big money scanner that can run a diagnosis on individual components.

 

[CDW6212R]

I feel that pain, it took me a year to track down a miss, which ended up being a coil pack that I had bought new a year before the miss began. I was going back over things again and again, and finally looked at the new parts I had put on.

The TPS has two sides of the shaft/pin shape that engages the TB shaft slotted end etc. Those two ends put together, can be oriented two ways. The TPS needs to be rotated in hand a certain amount, to engage the TB shaft properly. I don't know how to describe it better, it's been about ten years since I had one off and installed one back. So my fuzzy memory is making it hard to visualize myself, and then describe the two possible ways to install the TPS. Just take a closer look at the ends of the TB and TPS, and make it go on both ways, without putting the screws in. In the right way, the TB opens right with some resistance. The other way it doesn't feel the same as I recall.

 

[bigred4x4]

At this point I'm thinking I fried a circuit in the PCM switching the ground and signal wires I've messed with the tps position so much I don't think there is a way I haven't tried but I'll take one last look at it before I order a new PCM. It just seems funny how switching the wires made it instantly and permanently read a certain way no matter what combo of plug and sensor I use after I switched the wires back still ..... Exact same. I really can only be that I was thinking a short to ground or open circuit but it wouldn't just poof out of thin air once the wires where switched. Has to be something inside the PCM I read somewhere that at WOT the signal and reference pretty much become a loop but I'm not very well versed in electronics so I'm not really sure how it works I just assume the computer supplies a reference there is a ground and then the resistor inside the sensor sends back a voltage depending on position which a component inside the PCM can read therefore I do not quite understand how the PCM can cause a low signal voltage range. But supposedly a bad PCM can cause this issue or so I read but not really sure how or why because obviously it's not the sensor or the plug it can only be the PCM or the wiring and because I have had a similar issue with the IAC valve was wired wrong and it actually did end up frying the computer and both had to be replaced so I'm thinking this may be a similar situation

 

[CDW6212R]

The TPS receives a 5 volt signal from the PCM, a common voltage circuit I think. At the least before pulling the PCM, try to verify the 5V going to the TPS, and make it come out the signal wire of the TPS, in the 1-5 volt range you need. I think you can do that even if the PCM is fried.

The 5V going into the TPS is the main thing you need from the PCM. You can disconnect the other two wires from the circuitry going to the harness/PCM, and supply the ground separately to the ground terminal of the TPS. Thus,you should be able to verify the TPS function no matter what the wiring or PCM issues are. The TPS has three wires, one ground, one 5v input wire, and the output signal wire you need to be producing 1-5 volts, smoothly.

I'd jump the 5v power source from any usable wire, directly to the TPS connector power terminal. Leave the TPS connector unplugged for all of this. Provide a ground wire to the ground terminal. Then check the signal output terminal with a volt meter. Any good TPS should give you the 1-5 volts you need with that test.

 

[bigred4x4]

I get a 5v reference actually 5.03 with battery ground and 5.01 with sensor plug ground I get battery voltage minus .02 volts on the sensor ground and battery positive I believe the ground is supposed to have that .02v then I back probe the signal and I get .20

The code is a Ford specific p01120 tps sensor out of range (low).

 

[bigred4x4]

I need a lamens term for testing the wiring I noticed there is three times the resistance on the signal terminal as the reference terminal. The battery ground to signal didn't change the out come so I'm pretty sure the ground and reference is good.

 

[CDW6212R]

The ground terminal is the basic thing, measure power from that to a voltage source. You need to measure from the ground, and either the battery or the ground terminal should be virtually the same. Don't worry about an insignificant difference like that .02 volts.

Measure from ground to the reference terminal, it shows 5v, great, check. Then measure from ground to the signal terminal, which is the output from the TPS, the altered 5v converted into 1-5 volts going out, to the PCM. That's the one you want to see close to 1.0 volts at idle. Then as the TB is opened, that one signal is all that matters, it should rise smoothly to 4.5 volts or so. If you don't get the output near to the 1-5 volt range, then you think why.

If you don't have that, please check the TPS alone, without it connected to the wiring harness. Isolate the issue, which means get the PCM and all wiring out of the possibility. With just the three terminals exposed at its connector, apply a ground wire directly to the battery or a convenient ground screw etc. Then jump a 5v power source from a known engine harness wire, with the ignition on there are many of them. The TPS wire will do, if you suspect that, use an injector wire, just some wire to pull a 5v signal from, just to test the TPS for a brief few moments. Ignition off, use a wire to jump from a known 5v terminal, to the TPS reference(input) terminal. That then leaves just the output terminal, the signal you want to test. With a volt meter connected to that signal terminal, turn the ignition on, and watch the voltmeter as you gently open the throttle blade. If that doesn't show close to 1.0v at idle, and run to 4.5v or so, then the TPS is bad, or not installed properly.

There is very little TPS adjustment, just the play of the holes that you can twist the TPS one way or the other.

 

[bigred4x4]

I'm not getting the signal in the proper range with 4 different new sensor im going to try to cut some wire out put the other plug back in then go from there it seems to be a connection issue

 

[bigred4x4]

Ok I feel kinda dumb I retraced the wiring and when I put the old sensor back in I guess because I cut the wire so many times I still had it mixed up redid it one last time and viola!!! Back in business!! Thanks @CDW6212R for keeping up with this now hopefully it'll cure some little bugs I've been experiencing.

 

[CDW6212R]

Excellent, it's all good no matter what it takes. I've spent tons more time than what it should take, doing so many things, I can't count how many. I just keep going even though I'm slowing down.

 

[bigred4x4]

Have not test drove it yet but tps set at .96v at closed (supposedly a magic number) and it goes from 19-87% on the scanner so the signal is good. Maybe I'll try the pcm adaptive learning procedure on start up outlined in the owner's manual and see if that helps with anything as well.

I noticed last time I had the transmission out because I had the exhaust out and I pulled the plugs to turn the engine to get some oil going because it sat for so long I had some rich code problems before and I noticed the spark plugs were fouled as well as the O2 sensors I could clean the spark plugs but if I had to can you clean the O2 sensors as well? Don't know why I didn't clean the plugs before reinstalling them. I noticed the bank 2 O2 sensor switch is a little sluggish compared to bank one and on occasion the engine will run like crap when it's hot (being heavily worked off-road) and it's usually caused by bank 2 lack of o2 switch.

 

[CDW6212R]

The O2 sensor should be fine unless they have seen contamination from say anti-freeze. The plugs you can sand a little, but if they get fouled a lot, they can be bad and cannot be cleaned normally. If you suspect a plug at some point, if they have any age or saw some very rich times, just replace them. Plugs are very fragile in every way.

 

[bigred4x4]

Yea they've seem some Rich times but are not old I'll probably just replace them because there not expensive I have Bosch ir Platinum in there now and it is the kind with four contacts over electrode but I don't know I had cheap autolites before and I don't notice a difference maybe I won't go top end this time. That might explain some of the small hesitation issues.I mean these plugs were black! No antifreeze issues though I replaced them with the engine rebuild about two years ago. I've got my Rich and lean problems under control now it was the evap purge valve stuck open and a bad dpfe sensor.

 

[boominXplorer]

Put autolite coppers in there and change them every 30k. Your truck will like them way better than Bosch crap. Bosch plugs don't belong in Fords.

 

[bigred4x4]

Put autolite coppers in there and change them every 30k. Your truck will like them way better than Bosch crap. Bosch plugs don't belong in Fords.

That's what I'm going to do I'm almost positive these plugs are the root cause of the stumbling under load and light throttle. I put summit racing 8mm wires in it... over kill I know. but heck they where only $40 about the same as most other brands. what's your opinion on those.... unnecessary but ok or change it asap?

 

[boominXplorer]

I wouldn't worry about the plug wires, they are probably good.

 

[swshawaii]

Classic Bosch +4 thread from the past. Too bad the OP's pics are missing.

'01 EB Ex V8 bogging at full throttle | Page 4 | Ford Explorer and Ford Ranger Forums - Serious Explorations

 

[CDW6212R]

Ditto, high end plugs are just as likely to break when installing, and I've had two Bosch plugs bad before, one right after putting a set in about ten years ago. That was the last I've had of those.

 

[bigred4x4]

When I first installed the Bosch plugs one cracked and it missed when I fired it up so I had to replace one right away.lol that thread is crazy and here I thought by buying the most expensive plugs the store had I was going to get an edge on performance on the basic plugs lol. Yea I'll be getting rid of those soon. I saw something about a cat as well my cat was black on the inside from the rich problems I had the last time I had it out probably not necessary but I could probably need a new one of those as well 250.000 miles and 22 years old haha I bet it may be a wee bit on the clogged side.