Xu7p4 engine

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August
Posts: 38
Joined: 27 Jul 2021, 13:59

Xu7p4 engine

Post by August »

Citroen Xantia 1.8 16v (Xu7p4) 1999 manual.

What could cause rev hang on low rpm's? or is it normal?

I am suspecting coolant temperature sensor

MAP sensor is new.


Thanks in advance!
wheeler
Posts: 5401
Joined: 21 Sep 2002, 19:07
x 340

Re: Xu7p4 engine

Post by wheeler »

The first thing i would do is remove & clean the idle control stepper motor and the housing it sits in, you will need to use a rag on a screwdriver or similar to get right in to clean the housing properly & some carb cleaner spray. When you are cleaning the stepper motor do not try to move the plunger in & out by hand as this may damage it.
Once you re fit it switch the ignition on for 20 seconds (do not start the engine) then of for 20 seconds, repeat this about 6 or 7 times to reset the stepper motor. When you first start the car the idle may be all over the place for a few minutes till it settles.
August
Posts: 38
Joined: 27 Jul 2021, 13:59

Re: Xu7p4 engine

Post by August »

Thanks, will do!