Jerking XM v6 12v with stickshift

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PhilCrown
XM newbie
Posts: 2
Joined: Tue Jun 16, 2026 12:38 pm

Jerking XM v6 12v with stickshift

Post by PhilCrown » Tue Jun 16, 2026 12:59 pm

Greetings from the Netherlands everyone!

My name is Phil and I was wondering if anyone has experienced the following aswel.

My xm with the manual prv v6 drives very nicely, gives power when you need it and runs great stationairy, however only when letting go fully of the gas pedal and when giving gas again from closed throttle, it jerks slightly after half a second. You could be redlining the car and letting the pedal go untill the last mm and everything runs smoothly, but if you let it go all the way then it jerks. Working the pedal very softly and smooth does not change this.

Things that already have been changed:
Lamda sensor
Spark plugs
Knock sensors
Clutch


What could cause this and where should I look?

Kind regards!

xantia_v6
XM Guru
Posts: 1864
Joined: Sun Mar 31, 2013 5:09 pm
Location: Christchurch, New Zealand or Beaune, France

Re: Jerking XM v6 12v with stickshift

Post by xantia_v6 » Tue Jun 16, 2026 8:09 pm

It would be worth investigating the overrun fuel cutoff, and in particular make sure that the ECU is the correct type for manual transmission and that the throttle potentiometer is adjusted correctly.
1999 XM Exclusive V6 24V ES9 Manual (LHD) 115,000 km
1997 Xantia Exclusive V6 (RHD) 51,000 miles

Dieselman
Global Moderator
Posts: 15040
Joined: Thu Jun 18, 2009 6:44 pm

Re: Jerking XM v6 12v with stickshift

Post by Dieselman » Wed Jun 17, 2026 7:25 am

Start by cleaning out the idle air control valve and throttle flap and housing, check the throttle just goes completely closed at idle and check the throttle potentiometer is reading 0.5v Dc at throttle closed and over 4.5v Dc at WOT.

Check the TPS voltage is sound at the Ecu connector, I think should be pins 11-34 and 33-34 respectively.

Engine management information can be found in this linked to thread viewtopic.php?f=13&t=10588
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PhilCrown
XM newbie
Posts: 2
Joined: Tue Jun 16, 2026 12:38 pm

Re: Jerking XM v6 12v with stickshift

Post by PhilCrown » Wed Jun 17, 2026 2:52 pm

Thanks for the replies! I shall be checking this weekend and will post an update

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