Revs drop, rise & then drop again at 2000RPM

Questions specifically about a Diesel powered C3 (usually engine or fuel related problems)
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Diesel engine related problems
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My Name: zebedee2001

Experienced Member
Posts: 86
Joined: Fri Jan 16, 2015 4:40 pm
Model: C3 2006-2009, Facelift model
Year: 2009 (59)
Engine Size: 1.4
Fuel Type: Diesel
Mileage: 130000
Trim Level: Airdream+
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 diesel (70 PS)
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Hi People,

Another strange one with my car.......

In 3rd, 4th & 5th gear at spot on 2000rpm, as you accelerate the revs will drop by about 250RPM, rise by 500RPM, then go back to what they were before accelerating again. All this happens in a few seconds. I do not believe this to be clutch slip as I would expect the rev to rise significantly then drop back down (I had this before I changed the clutch around 30K miles ago). Any ideas what could be wrong?
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My Name: Ozvtr

Moderator
Posts: 957
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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If you have a LEXIA I would recommend monitoring the throttle position sensor and see what the butterfly valve is doing.
Other than that I'm sorry but I don't know much about diesels.
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My Name: C3CAR

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Posts: 2634
Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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Try bleeding the fuel system with the hand primer, there could be air in the fuel.
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