TPS low voltage over and over when replaced

[courier6ix]

Mk3 Astra TPS low volt (22) code and hitching in low revs

Had this happen a few times and replaced the TPS each time but it keeps comming back not sure why gonna go chase the wires a bit. Each time I replace the TPS the hitching stops for a while.

We also had an issue with the fueling on throttle too before we advanced the timing where if you didnt slowly press the peddle it would not fuel correctly and try to stall, it still does this but only if you stomp the throttle flat to the floor.

There’s another issue too where sometimes when off throttle the engine breaking would be so aggressive you’d think I was pressing the brakes untill idle and then letting off (it does this constantly when TPS is unplugged)

It’s a x14ne I think but it’s the SPI hi-torque.

Not sure if any of these issues are 100% related but if anyone has had experience or any ideas that would be great!

 

[A.tapos]

Can you check the voltage at the tps while connected.much better then when disconnected as no load.
You should have a
pin at 5V(sesnor supply)
0V(sensor ground) and
one between 05/1.0V(closed throttle) sensor signal
You can then slowly open throttle and watch sensor signal raise to 4-5/4.99 volts smoothly

 

[courier6ix]

Can you check the voltage at the tps while connected.much better then when disconnected as no load.
You should have a
pin at 5V(sesnor supply)
0V(sensor ground) and
one between 05/1.0V(closed throttle) sensor signal
You can then slowly open throttle and watch sensor signal raise to 4-5/4.99 volts smoothly

How would I do this? I have a multi meter

I assume I’d have to use the multi pins into the wires (Idk which to which) or what setting to put the multimeter on

 

[courier6ix]

So I asked my dad to walk me through checking and my TPS shows steady voltage etc is all correct (had multi meter on 20v and it shown 0.4 at closed at 4.23 at fully open if I remember correctly)

So I think my issue is wiring or dirty connections to ECU or my ECU is cooked or something lol

 

[A.tapos]

So I asked my dad to walk me through checking and my TPS shows steady voltage etc is all correct (had multi meter on 20v and it shown 0.4 at closed at 4.23 at fully open if I remember correctly)

So I think my issue is wiring or dirty connections to ECU or my ECU is cooked or something lol

That’s probably about right mate.did it go up smootly?

 

[courier6ix]

That’s probably about right mate.did it go up smootly?

Yeah it did as far as I could tell

 

[A.tapos]

Id say its unlikely ecu as they hardly ever fail.
Possibly dirty connection on exu pins.could unplug it/clean and plug back in a few times

 

[A.tapos]

Also tps code may not be the actual fault you are seeing.if its hunting and going lean id say you have an air leak

 

[courier6ix]

Id say its unltto exu as they hardly ever fail.
Possibly dirty connection on exu pins.could unplug it/clean and plug back in a few times

I don’t know what unltto exu is…

 

[A.tapos]

Sorry fat fingers TPS code may not be relevant
Does it come straight back?

 

[A.tapos]

I don’t know what unltto exu is…

Unlikely engine ecu

 

[courier6ix]

Also tpa code may not be the actual fault you are seeing.if its hunting and going lean id say you have an air leak

Interesting… it behaves this way then I get the eml and sometimes it behaves this way without eml but its always on very very low throttle and revs

 

[courier6ix]

Sorry fat fingers TPS code may not be relevant
Does it come straight back?

No when I replace and clear the code it takes about a month before it starts suffering and giving eml

 

[A.tapos]

Generally if it is a hard fault with wiring or sensor it will come straight back as soon as you drive it/switch it on and off a 3 times.

 

[courier6ix]

Well I thought this too

Generally if it is a hard fault with wiring or sensor it will come straight back as soon as you drive it/switch it on and off a 3 times.

so do you think it could be faulty ECU? I was told it also could be a bad earth somewhere.

I think with the other issues i mentioned I’m gonna have a fun time ironing out the kinks.

 

[A.tapos]

On the wiring diagram the ground goes straight back to the ecu.
So if there are no other fault codes unlikely to be a ground.and as your sensor signals are ok it looks like its not wiring.
Its a single injector?
Are they new or used TPS?
Also check for air leaks

 

[courier6ix]

On the wiring diagram the ground goes straight back to the ecu.
So if there are no other fault codes unlikely to be a ground.and as your sensor signals are ok it looks like its not wiring.
Its a single injector?
Are they new or used TPS?
Also check for air leaks

All were brand new TPS but cheap shite (I say cheap but still 20/30£), it is SPI and with the air leaks issue we were originally missing a vac tube from the intake hat and we’re not really sure where they all go so I need to find a vac tube diagram.

There is a split pipe from the brake servo to the actual intake manifold (the hard plastic one with a knot on) but it’s at the connection side of things and I don’t currently have a replacement I was thinking maybe wrapping a load of electrical tape round it for a quick fix lol.

 

[DavebGsi]

do all 3 wires go back to the ecu, or is one a ground wire? have you checked and cleaned them?

 

[courier6ix]

do all 3 wires go back to the ecu, or is one a ground wire? have you checked and cleaned them?

Haven’t chased it all the way back yet tbh