S1 V6 auto back on the road at last!! - Problem solved!!

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xantia_v6
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by xantia_v6 » Wed Feb 22, 2017 10:44 pm

Are you sure that the throttle butterfly is moving through the full 90 degrees?
1999 XM Exclusive V6 24V ES9 Manual (LHD) 105,000 km
1997 Xantia Exclusive V6 (RHD) 45,000 miles

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MTXM
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by MTXM » Wed Feb 22, 2017 11:05 pm

Here are some photos of the TPS for further info. Regards, Matthew T.
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1989 V6 Exclusive (Poland car)
1990 V6sei auto (grey auto)
1990 V6sei manual (gold car)
1990 V6.24 Pallas (Germany car)
1990 V6.24v (Scotland car)
Other previous XM sold and broken too many to mention!

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MTXM
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by MTXM » Wed Feb 22, 2017 11:08 pm

Are you sure that the throttle butterfly is moving through the full 90 degrees?
Yes Mike and there is nothing to prevent the movement except for the stay where the cable connects. As already mentioned before, I think it is interesting that the range is cropped at both ends by a significant factor and not just moved up or down a few vs! Regards, Matthew T.
1989 V6 Exclusive (Poland car)
1990 V6sei auto (grey auto)
1990 V6sei manual (gold car)
1990 V6.24 Pallas (Germany car)
1990 V6.24v (Scotland car)
Other previous XM sold and broken too many to mention!

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Dean
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by Dean » Wed Feb 22, 2017 11:21 pm

So the tps checks out fine but as soon as you bolt it to the engine it throws the voltage signal out of spec? Because if that's what is happening and with replacement sensors AND given the flickering from the tachometer and maxed out reading from the O2 sensor I would definitely say it's nothing to do with the tps and more to do with the wider electrical system.
The whole thing just seems wrong somewhere........

D
92 Citroen XM Prestige 3.0i Auto R.P5678
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by MTXM » Wed Feb 22, 2017 11:44 pm

Yes I see your thinking Dean, but I simply cannot find any other faults, with the ecu, other sensors and wiring all thoroughly checked and apparently correct. There is the wild reading from the oyygen sensor on the Lexia as you say, but then the throttle voltage readings are actually much lower when checked with a meter.

The flickering from the tacho is not that major I think and is the needle is just bouncing due to the fuel cut off effect. I took the gold car out earlier today and noticed the tacho on that was quite jumpy.

At the end of the day, not that much has been disturbed electrically in the last engine removal, the ecu plugs and adjacent relays, connectors under the lhm tank, earths against the wings, connections to crank, oxygen and pressure sensor ... that is about it really!

The TPS readings may not be the only issue, but they are a significant clue I think and obviously must be corrected.

With regards,

Matthew T.
1989 V6 Exclusive (Poland car)
1990 V6sei auto (grey auto)
1990 V6sei manual (gold car)
1990 V6.24 Pallas (Germany car)
1990 V6.24v (Scotland car)
Other previous XM sold and broken too many to mention!

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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by MTXM » Thu Feb 23, 2017 12:06 am

I jsut look a look at these which may or may not be relevant bu there is quite a lot of info on calibrating a TPS!
http://www.autronic.com.au/throttle_pos ... rning.html" onclick="window.open(this.href);return false;
http://wiki.seloc.org/a/Throttle_Position_Sensor" onclick="window.open(this.href);return false;
http://www.fixkick.com/sensors/tests/TPS-testing.html" onclick="window.open(this.href);return false;
http://forums.g2ic.com/forum/assistance ... sir-g-spec" onclick="window.open(this.href);return false;
As I have tried other ecu without any change perhaps I am clutching at straws!
With regards,
Matthew T.
1989 V6 Exclusive (Poland car)
1990 V6sei auto (grey auto)
1990 V6sei manual (gold car)
1990 V6.24 Pallas (Germany car)
1990 V6.24v (Scotland car)
Other previous XM sold and broken too many to mention!

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Dean
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by Dean » Thu Feb 23, 2017 12:08 am

Ok so not much has been off the engine or played with, yet a perfectly happy engine comes out of the car, has a flywheel changed, goes back in and now there are what seem to me at least to be inaccurate data coming from the O2, TP, gear selector and possibly map sensor. Components that have been doing their job perfectly for years all start messing about now? It just seems implausible and when something seems that way ................
I just can't piece it together but there is something else.
The engine is lean we know that, the O2 sensor is reporting a rich mixture so I would guess that is at fault and causing the lean burn so I think it's best to start there really.
That tps looks very strange, not seen one like that before.

D
92 Citroen XM Prestige 3.0i Auto R.P5678
14 Mitsubishi L200 Trojan
89 Talbot Express motorhome Auto-Trail coachbuilt (looking for bonnet, wings, scuttle panels etc)

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xantia_v6
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by xantia_v6 » Thu Feb 23, 2017 5:59 am

To add a different check (and one for an unlikely problem) you might check that the ignition timing is correct (specifically not retarded) referenced to piston TDC, not using the "flywheel" as a timing reference. This would eliminate the possibility that your new starter ring has been manufactured with the timing ring in the wrong alignment.
1999 XM Exclusive V6 24V ES9 Manual (LHD) 105,000 km
1997 Xantia Exclusive V6 (RHD) 45,000 miles

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White Exec
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by White Exec » Thu Feb 23, 2017 7:39 am

Yes, it may well be something other than the TPS, but the voltage readings from that are not right - and John has confirmed that below a certain figure ECU will operate in limp mode (less than 4.5v at full throttle).

The TPS is probably like other similar ECU sensors: when the IGN is switched on, the ECU very quickly starts to "learn" the voltage range being produced by the sensor, as it gets put into use by driving. (A similar thing happens with the suspension sensors.) As it learns the voltages being offered, it uses them to calculate what the ECU should do, and progressively replace the backup values used when first switched on. But, note John's statement about limp mode, in the absence of adequate voltage range.

A couple of things you should do:

1. You say that another TPS produces a good voltage range when operated 'loose'. That's good, and confirms that the wiring to it is ok. What happens if you fit this TPS to the car, in place of the suspect one? What voltage range will it kick out then?

2. Measure the resistance across the ends (0v and 5v connections, not the variable 'wiper' output) of the TPSs you have, disconnected from the car. What are these figures?
Chris
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Re: S1 V6 auto back on the road at last!! - fourth time luck

Post by MTXM » Thu Feb 23, 2017 9:47 am

Firstly Dean I would question the readings obtained from the Lexia on the O2 and MAP sensors since there was split MAP hose at the time and I have known the Lexia to get gear setting wrong before! Once I have my equipment up and running hopefully I can produce more meaningful data and make comparison with other cars.

I do not think there is any issue with the ignition timing Mike as the engine was running fairly well initially and has gone downhill since and the replacement starter ring is definitely correct.

In response to Chris I have tried several other TPS sensors on the car and all operate the same which includes the original and a known good example, so I do not think the sensor itself is the problem. I can confirm that the resistance between the +/- terminals on a typical sensor is 3.7kohms - if I have the digit in the right place!

My feeling at present is that I just have to get to the bottom of why the TPS is reading between 2 - 3v when it should be 0.5 - 5v and solve this issue, since until I do it will never be right!

With regards,

Matthew T.
1989 V6 Exclusive (Poland car)
1990 V6sei auto (grey auto)
1990 V6sei manual (gold car)
1990 V6.24 Pallas (Germany car)
1990 V6.24v (Scotland car)
Other previous XM sold and broken too many to mention!

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