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

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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 » Fri Feb 24, 2017 10:59 am

The Lexia test will be interesting.
Your earlier test (video - chucking in a cup of fuel) does rather suggest fuel starvation - i.e. injection, or lack of it.
Chris
1996 XM 2.5TD Exclusive RP7165 Polar White
1992 BX19D Millesime RP5800 Sable
1989 BX19RD Delage Red Deceased; 1998 ZX 1.9D Avantage auto Triton Green Company car 1998..2001; 2001 Xantia 1.8i auto Wicked Red Company car 2001..2003

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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 » Fri Feb 24, 2017 6:57 pm

Thank you Chris and repeated the cup of fuel test earlier today just to check nothing had changed, with the same satisfying result! The engine is clearly being told that it does not need fuel when it does, which if the last Lexia test is to be believed is a combination of distorted/incorrect O2, TP and MAP sensor readings. The question is what might cause this situation to occur, given the ecu, sensors and wiring all appear to be in order? On a more positive note I attach pictures taken earlier today and the gold car at least is a joy to drive. With regards, Matthew T.
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1989 V6 Exclusive (Poland car) - Now living in a local Motor Museum!
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 Mar 02, 2017 6:03 pm

After some further checks I have found a disparity with the wiring compared to another car in that one additional ecu terminal appears to go to earth! The ecu terminal is no.32, which does include the O2 sensor circuit and front and rear knock sensors, so that might be what is upsetting the Lexia reading, apart from the running of the car! I am not sure what is causing the further earthing at present other than a possible short circuit somewhere and any suggestions would be most welcome! Regards, Matthew T.
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Last edited by MTXM on Thu Mar 02, 2017 6:25 pm, edited 1 time in total.
1989 V6 Exclusive (Poland car) - Now living in a local Motor Museum!
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 Dean » Thu Mar 02, 2017 6:21 pm

those three sensors should be earthed together to the inlet manifold via the ECU, i remember seeing that on my early loom, think the blue canister purge valve uses that ground too.

D
92 Citroen XM Prestige 3.0i Auto R.P5678
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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 » Thu Mar 02, 2017 6:32 pm

That is helpful Dean, but I wonder why terminal 32 does not apparently go to earth on the other car? Does it look like there should be an earth at 32 on the diagram? Regards, Matthew T.
1989 V6 Exclusive (Poland car) - Now living in a local Motor Museum!
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!

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

Post by sdelasal » Thu Mar 02, 2017 6:52 pm

Matthew - 32 looks like a signal common return to me - i assume you are testing with the ecu disconnected and so you are seeing a (mis)connection /short to earth in the wiring loom. To try & determine where, you could disconnect the o2 sensor, then knock 1 (151) then knoock 2 (152) - (added afterthought: I see a couple of temperature sensors too that are connected 907 & 909).. one at at time and see if the continuity to earth disapears. That should help you figure out whether the earth is in a faulty sensor or in the wiring.

That wiring diagram is hard to follow - 151 & 152 are shown with a connection to terminal 2 on the ecu (earth) - via those thick black verticle rectangles - do you have a key explaining what that symbol means? Are the knock sensors earthed via the engine block ? Do they have a 2 or 3 pin connector?

Is your lexia working?
Last edited by sdelasal on Thu Mar 02, 2017 7:38 pm, edited 1 time in total.

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

Post by xmexclusive » Thu Mar 02, 2017 7:12 pm

Hi Matthew

Might be worth looking again at XM 1-52 that I posted in this thread on 17 Feb.
Fault symptoms are very similar to yours.
Diagnosis is wrongly wired Oxygen sensors destroyed them.
ECU pins 32 & 35 are mentioned.

John

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

Post by MTXM » Fri Mar 03, 2017 10:02 pm

Apologies for the late response and in the meantime I have found the my other early V6 also has earthing on ecu pin 36, so it might be a change to the wiring and not the issue as I had thought! I have definitely not wrongly connected the 02 sensor plugs John as I did this on my rhd 24v earlier and learnt the lesson. The laptop arrived today Steve but unfortunately dos not have Windows XP as advertised that is needed for the Lexia!! With regards, Matthew T.
1989 V6 Exclusive (Poland car) - Now living in a local Motor Museum!
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 cxprestigeauto » Fri Mar 03, 2017 10:23 pm

Matthew, I have a couple of surplus XP laptops. Let me know if you need one posted out.

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

Post by Dieselman » Fri Mar 03, 2017 10:26 pm

XP...XP...! DOS is what you need.
92 2.1SED M.RP5740 ECZ Sable Phenicien
92 3.0 V6-24.Rp 5713 EXY Black
92 2.1SD M.RP 5685 ENT Blue Sideral
Prev
90 2.1SD M.RP 5049 EJV Mandarin
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