TPS sensor from ebay - any good?

M

Micra Steve

Thinking I might need a new Throttle Position sensor for my 2001 K11, so I'm interested to see if anyone has had any luck with a cheap ebay TPS.

I've had a problem with a low idle when warm for some time and after plugging in my OBD2 scanner it was showing a TPS reading of around 7% at idle - I think I'm right that it should be around 10%, so it seemed that the TPS could be the cause.

Tried cleaning the TPS electrical contacts a few days ago, with CNC MAF cleaner, but no improvement.

This morning I went for a short drive and as I was reversing into a parking space the engine started revving very high - had to turn the engine off.

Connected up the scanner when off and the TPS reading was about 30% - after blipping the throttle a few times it gradually started to come down to around 10%.

When I started it up a bit later to drive home it was OK, but this seems like an extra reason to invest a few quid in a new TPS to see if it helps.
 
Been there, done that, all of it. Save your money, a cheapy off ebay didn't do it for me, waste of £8 Made it worse if anything.
I dis-connected my TPS and that did it. A few minor idle blips on very, very rare occasions, other than that - fixed.
Try it bud.
 
davyboy said:
Been there, done that, all of it. Save your money, a cheapy off ebay didn't do it for me, waste of £8 Made it worse if anything.
I dis-connected my TPS and that did it. A few minor idle blips on very, very rare occasions, other than that - fixed.
Try it bud.
Click to expand...

I've already tried disconecting the TPS to see if it helped with the low idle - didn't make any difference.

I think there is a fair chance that disconnecting the TPS would solve the problem of sudden high revs - so if that happens again and the car becomes undriveable, I'll give it a go.
 
Some very bad advice in this thread...

The low idle could be caused by improper base idle/timing. However, fixing the TPS first is a step in the right direction.

The TPS is a very important instrument, and should never be disconnected like davyboy suggests. When you disconnect the TPS, it puts the car in timing mode, and locks the ignition timing to 15*BTCD. Driving the car with the TPS unplugged is stupidly silly, and will hurt both your gas mileage and engine.

The mounting point on the TPS is adjustable, have you tried loosening it, and twisted it so you get it to read 0%? If you cannot set the TPS to 0%, you need a new sensor. In some cases the wiring, especially the ground, could be bad, not allowing the sensor to perform like it should. Start by adjusting the TPS before ordering a new one! :)

If you don't have an obd scanner, use a multimeter and make sure the TPS plug reads:
-Closed = 0.45-0.65V
-Part throttle linear between 0.65-4V
-Wide open throttle > 4V
 
Daniel - it's a later, coilpack K11 - the TPS isn't adjustable by swivelling on these, it's a fixed, one position screw.

Just connected the scanner up to see what it's reading this morning

With ignition on, but engine off, the TPS readings are jumping about all over the place - anywhere from 10% to 30% - without me touching the throttle.

This is clearly wrong - I've measured it in the past and although the reading at idle seemed too low, it at least was fixed and not moving about - unless I pressed the throttle of course, in which case it rose steadily, as expected.

Also put my multimeter on the TPS connector to see if there is a correct reference voltage being supplied - and I can't get a reading of anything except zero volts on any of the 3 pins.

I think I'm doing it correctly - I read online that you should connect the negative lead of the meter to the battery negative - and then connect the positive lead of the meter to the pins in the TPS connector - with the ignition on.
 
Micra Steve said:
Daniel - it's a later, coilpack K11 - the TPS isn't adjustable by swivelling on these, it's a fixed, one position screw.
Click to expand...
Ah my bad, that's unfortunate :/

With ignition on, but engine off, the TPS readings are jumping about all over the place - anywhere from 10% to 30% - without me touching the throttle.
Click to expand...
That is not good. The ECU needs to see 0% to enter throttle closed ignition tables, this will affect your idle quality.

Also put my multimeter on the TPS connector to see if there is a correct reference voltage being supplied - and I can't get a reading of anything except zero volts on any of the 3 pins. I think I'm doing it correctly - I read online that you should connect the negative lead of the meter to the battery negative - and then connect the positive lead of the meter to the pins in the TPS connector - with the ignition on.
Click to expand...
Tried it with the car running? One pin should have 5V.

Another thing to check with the multimeter is continuity on the ground pin. Have the car OFF for this, and check the GND pin resistance. Should be as close to 0Ohm as possible. If you get anything between 1-3Ohm, you need to reground the circuit (common on older wiring harnesses)

I'd say you need a new TPS sensor. You should be fine with the ebay one :)
 
Hello Daniel. Thanks for all of that mate, I've been running without for a few months now and if anything my mpg is marginally better!!!!
Engine seems fine, performs as it should, or seems to????
 
Micra Steve said:
Does it have to be running? Everywhere I've read online simply says ignition on.
Click to expand...

It can be tested with the key in the ON position, not in the ACC position.

davyboy said:
Hello Daniel. Thanks for all of that mate, I've been running without for a few months now and if anything my mpg is marginally better!!!!
Engine seems fine, performs as it should, or seems to????
Click to expand...

With TPS unplugged, if the trans is in neutral and the engine coolant temp is at least 60ºC, the ECU enters "SET IDLE/TIMING" mode. If the trans is in gear and the vehicle speed is above 4kmh, the TPS DTC is set. Also, load and RPM are used to determine whether the throttle is open or closed.

In timing mode with the throttle closed, the idle PWM is at a fixed rate (10% on a micra?) and the ignition timing is fixed at 15 degrees . If the throttle is open, the timing map is used and all other ignition trims are applied. So that explains why you still get good fuel mileage.

Also, since the TPS sensor isn't responding, accel fuel trims are not applied. This means you're getting way worse throttle response than you should :(

Do your engine a favour, and get your TPS working again :)
 
Daniel

On a side note - you mentioned earlier about timing.

When I look at the data on my scanner I see the figure for SPARKADV at 63 when the ignition is on, engine off.

When I start it up, SPARKADV reads around 20 to 25 at idle - it's not stable, but that's probably because the revs are jumping around a bit.

Are these figures OK?

I'm due to change my spark plugs shortly, as I thought it might help the low idle problem.

I've also ordered a new TPS off ebay - it's worth a shot for just £7 - if the problem isn't a faulty TPS, then I've got a spare one for the day it DOES need replacing.

I checked the TPS connector in the On position, not ACC - so a problem with the wiring maybe?

The cable that goes into the TPS has a 90 degree bend in it - and I've been bending the wire as I disconnected it from the sensor
 
Last edited:
Dash lights were on - definately in the On position, not Acc

The probes on my meter are a bit chunky - but I'm pretty sure they are touching the contacts in the connector.

But if I had no 5 volt reference voltage, I would have thought I'd also get no TPS readings on my scanner - I'd expect it to show a fixed 0% or fixed 100% - not jumping around all over the place.
 
Thanks - as I thought, throttle position should be 10% give or take a small margin - so 9% is spot on.

The Timing Adv is, I presume, the same as the SPARKADV figure I see on my scanner?

15 is what I'd expect it to be at idle - which is why I questioned the 22 or 23 figure I'm getting - it seems a touch on the high side to me.

It will be interesting to see what new plugs do.
 
Still waiting for my new TPS to arrive (due tomorrow), but I'm increasingly convinced that the problem is not getting any reference voltage supplied to the sensor.

All 3 pins read 0 volts on my meter.

There is a really sharp bend in the cable leading to the TPS, so it could be that one of the wires inside the outer sheathing has broken - I'll have to strip it back to investigate.

I've been getting some P0100 and P0110 codes too, for the MAF - is it possible that a problem with supplying a reference voltage to the TPS could also affect the supply to the MAF?

Do they share the same wiring?

It would make sense, as I've cleaned/changed the MAF with no improvement.
 
on the preface all the sensors have their own dedicated earth wire to the ecu, and the signal wires are wire mesh shielded too steve (anti interference measures)
have you measured the wires while still connected ?
 
This is a 2001

Haven't measured with the connectors in the sensor (not sure how to) - I've been probing the pins on the unplugged connector, as that's the way I've seen it explained.
 
Not concerned about the signal voltage at this stage - I can see that's all over the place from the live data on my scanner.

The most important first step is trying to establish if the TPS is getting supplied with the correct 5v reference voltage - as nothing is going to work correctly without that - and as you say, I should be able to do that from probing the disconnected plug, but I'm getting zero volts.

Only thing I can't understand is if there's a fault with supplying a reference voltage, why am I seeing any kind of signal voltage on my scanner data?

Surely I should be seeing 0%, or at least some figure that is fixed and not jumping around.
 
When mine was playing up, if I pushed, pulled and bent the wires the idling settled down to normal. That made me think that the problem was with the wires going into the TPS and I still think that was so.
Anyway, she's idling fine without it.
 
Tried flexing the wires around, but it made no difference - highly suspect a problem there though.

Had to go out today and it was revving it's head off when idling - but OK at speed - athough I'm now getting flat spots at times with loss of power and slight kangarooing.

I've got to make a short trip in the morning so I'll try disconnecting the TPS - I know it won't fix my low idle, as I've already tried that, but I hope it will fix the engine surging.

I'm going to get my new TPS in tomorrow hopefully - plus change my plugs, if my neighbour has the necessary tool - if that doesn't help I'm running out of ideas and will have to resort to some professional help, as the car is close to undriveable now.

Before I had this k11 I had a 1996 Mazda 626, which probably had 150,000 miles on it (don't know exactly because I'm pretty certain it was clocked) - drove it for 13 years without a single fault and didn't spend a penny on it, except for the odd oil change/ new tyres etc

Basically, I abused it and it just kept coming back for more and more - just like K11's are supposed to do, so I'm told.
 
When I took mine off it was a few miles of driving before it all settled down to where it is today.
Initially the idle was to low, but that settled down with driving. After just doing it she would idle, and conk out occasionally at junctions when coming down from speed, but again it settled. Happy with it now, although very, very occasionally low idling, but only lasts a few minutes and it settles again.
 
Went for a drive with the TPS disconnected this morning (still waiting for the new TPS to arrive) - completely solved the problem of surging high revs and jumping around all over the place.

On my scanner it now shows the TPS reading as a fixed 100% - instead of jumping around anywhere from 10% to 50%

So I think it's safe to say that the TPS is the source of the problem - otherwise disconnecting it wouldn't have made any difference.

But does this mean that it IS the TPS itself, rather than a fault in the wiring supplying the sensor?
 
davyboy said:
Could be either bud. Still, she's ok now and driving like mine. That's a fix in my world.
Click to expand...

Not quite a fix.

I noticed a slight pinking that wasn't there before, so I think the ECU has somehow advanced the ignition timing slightly as a reaction to unplugging the TPS.

And it's made no difference at all to my low idle - which I manage to cope with by keeping my headlights on, which raises the revs a touch and stops it from cutting out at junctions.

But at least it's driveable and I can get to the car boot sale in the morning - hopefully the new TPS will arrive tomorrow and be a better solution.
 
Went for a 2nd drive today, with the TPS disconnected (new one STILL not arrived) - driving great now.

The very slight pinking I heard yesterday has vanished - checked the timing with my scanner and it's spot on.

I take on board what Daniel said about disconnecting the TPS being a very bad idea - makes sense, it is obviously there for a reason - but is there any VALID way to set an engine up to run without a TPS?

From his description, it seems the only drawback to running without a TPS is reduced performance - but frankly, at the speeds I drive, I doubt I'd ever notice!
 
davyboy said:
Just live with it bud - I do.
Click to expand...

Personally, I'd be happy to - the only problem I can think of is with the MOT - would it be an MOT fail with the faulty TPS code set?

You can wipe the code just before the MOT of course, but that in itself is a fail I believe, as the ECU stores the fact that codes have been wiped recently.

Anyway, I've also invested £12 in a used Bosch TPS - described as fully tested and working and with a money back guarantee, so not much to risk - pretty good deal I think, as the cheapest brand new Bosch TPS is around £53 on ebay.

I'm thinking that a used OEM part is probably going to be a lot more reliable than a brand new cheap Chinese knock off.
 
the coilpacks run a default safe map if one of the sensors are down, hence why they run better with the maf disconnected when the maf is busted, you guys need to find the root cause of the fault tbh
 
TPS maximum resistance is approximately 4.5 K ohms. Measured with a multimeter, 0-4.5K ohms variable smooth steady increment on the throttle opening and closing.

Erratic voltages are interference noise originated by high impedance connections, fuses, floating earthes and sometimes the alternator. Check power supply battery voltage and alternator output charging voltage for excessive ripple voltage with engine running.

Check earth return, maximum 100 mV (that is 0.1 volts) allowable for any non-floating computer CPU earth system. Excessive noise to signal ratio renders control system us.

Check the throttle plate is closing and not sticking obstructed by carbon build up.

Chase down and establish 5 V reference power supply to the TPS?

5V output may only be present when the TPS load is connected to the power supply.

Therefore back probe the TPS connector plug when it’s in situ connected to the TPS. Improvise to extend the multimeter test probes to reach the connector contacts using 0.1mm solid copper insulated wires or tee pins. NB; Using floating tee pins has a high risk of shorting the wires together and trashing the engine management CPU!

TPS testing tutorial video;
 
frank said:
the coilpacks run a default safe map if one of the sensors are down, hence why they run better with the maf disconnected when the maf is busted, you guys need to find the root cause of the fault tbh
Click to expand...

Absolutely - I don't have any intention of running without a TPS if it's possible to fix it without too much hassle/expense - hopefully the new one, when it arrives, will do the job.

plmval - thanks, some useful pointers there if replacing it doesn't work.
 
Good thinking there Steve. I never thought of a second hand original, I'll rob one next time I'm at the scrappers.
Can't see it being a fail on the MOT, no reason too.
Let me know how your scrappy one goes.
 
davyboy said:
Good thinking there Steve. I never thought of a second hand original, I'll rob one next time I'm at the scrappers.
Can't see it being a fail on the MOT, no reason too.
Let me know how your scrappy one goes.
Click to expand...

Will do.

Actually, it was off ebay - annoyingly, there are no scrap yards within about 20 miles of me - not sure how much you'd have to pay for one at a scrappy (even if you were lucky enough to find one), but I suspect they'd want at least a tenner off you - so with the cost of driving there to pick it up I don't think it would work out any cheaper.

Just search using the Bosch part number (0280122014) - and make sure the sensor actually has Bosch written on it, so you know it's OEM - there is another on ebay at the moment for £14.95

You'll see them described as Vauxhall or Saab or 1-2 other makes - this same sensor fits loads of different cars as well as Micra's - as long as the part number is correct it will fit.

I considered going the whole hog and buying a new one - but then I thought, the car is 14 years old - every single part on the car is 14 years old already!
 
davyboy said:
I think you missed my line in the post "I'll rob one" LOL
Click to expand...

I thought you meant "rob" in the sense of a dead cheap price!

But seriously, if you are trying scrapyards it's a good idea to check out a seller of the OEM Bosch part online, and print out the list of all the vehicles that part is compatible with.

Then, you don't have to restrict yourself to looking for K11 Micra's, which will probably make the search extremely difficult - you'll have a large range of cars to look at that could supply the exact same TPS.

Naturally, the same principle would also apply if you were looking for any other type of sensor - most of them fit many other cars.
 
Plenty of micras where I go to mate, I might have a look tomorrow, the buyer of the soft top is going there with me....so we'll fill our boots, LOL
 
Just put my used Bosch TPS in.

Connected up my scanner with the engine off and the readings look good - not jumping around any more, showing crazy values - just a rock steady reading that increases gradually as you press the throttle.

So it looks like it WAS the TPS itself and not a problem with the wiring.

Taking it for a proper test drive tomorrow.

One thing I have noticed - with my old ebay TPS (before it went completely bad and started jumping around) the readings would actually DROP slightly when you put a very light pressure on the throttle, before rising after pressing the pedal fully.

Obviously that's not right - and as you would expect, caused the revs to drop when you put a very slight pressure on the throttle.

With the Bosch TPS, there is no such drop - the reading is at 7.8% with no foot on the throttle and with a very light pressure it just rises very slightly, exactly as it should.
 
Test drive today.

The used Bosch TPS is brilliant - no surging high revs - fixed it completely.

Even my low idle has definately improved - which I wasn't really expecting - still a tiny bit on the low side, but it's not stalling, like before.

From now on, I will choose used OEM parts over brand new made in China rubbish every time.

Of course, brand new OEM would be better still - but I question if it's really worth it, if you can get a used part, with a guarantee, for a fraction of the price.
 

Similar threads

S
k11c tps sensor
Replies
13
Views
4K
davyboy
davyboy
S
Ebay MAFs any good?
Replies
6
Views
1K
frank
frank
Baz
Question about TPS
Replies
12
Views
2K
Baz
Baz
thespooner
k11c TPS and other problems
Replies
0
Views
662
thespooner
thespooner
C
TPS voltage
Replies
2
Views
108
CMF_CENTI
C
Back
Top