Xantia 1.8I 16V Runs Bad Up To 2000Rpm

[pehorunkl]

Hello!

 

My Xantia 1.8i 16V behaves very strange for a couple of years and no mechanic found the solution.

The car runs slightly rough on idle. When trying to accelerate from standing when the accelerator pedal is pressed little bit to much the car starts to slow down. I have to press the pedal very lightly up to 2000rpm and then it pulls normally.

The car has lpg installation which works ok but can't be tuned to optimum because of running on gasoline problems.

Anybody has any idea what is wrong???

 

Kind regards,

 

Tomaz

[paul.h]

Welcome to the forum.

 

A list of what checks have already been done on the car would help but things that can affect running include:

- wrong fuel/air mixture - an injector fault, air filter blocked, air leak, air flow meter/MAP sensor fault, fuel filter needs replacing, possibly a stretched accelerator pedal cable, throttle plate and body needs cleaning, worn cam shafts, wrong valve clearances.

- spark plug or ignition coil fault.

- worn engine so compression is low.

- valve seats not giving a good seal.

- temperature sensor faulty.

- blocked exhaust.

- engine timing is wrong - check the timing belt is installed correctly.

[pehorunkl]

Thanks for answer. I thought of list but wanted some answer from blank.

 

- Injectors were cleaned and tested. I also interchanged injectors from my other xantia which works fine. No change.

- Few months ago at 240000km the timing belt was changed in official Citroen garage that I trust.

- The MAP sensor was previously changed for testing purposes with new one without significant change.

- Fuel filter was changed. The fuel pressure was checked.

- Air filter changed regularly.

- Spark plugs changed.

- Ignition coil changed.

- Recently I changed entire throttle body.

- The exhaust system was renewed together with catalysator when needed.

 

I have this car for nine years and made 130000km and take care on regular basis but can't find out where this problem lies.

Car performs well. Reaches top speed 195km/h (deutsche autobahn) and pulls well above 2500rpm till red line.

It just idles roughly and has difficulty accelerating from idle to 2000rpm. Also when running in low rpm, the engine fault indicator lights.

[paul.h]

If the engine management light is coming on have you had the fault code read since this may give a good indication of the fault ?

 

May be you could do a compression test to see if the engine is worn or the valves are not seating and are leaking. Then check the valve clearances since these can be adjusted plus look at the cam shafts to see if they are worn.

[pehorunkl]

Ah. I forgot to mention that when running on lpg system symptoms of running rough on idle and till 2000rpm disappear. Only at beginning when engine isn't yet at working temp idle is slightly rough but accelerates without problem on lpg.

[paul.h]

It is probably then a problem of not having the right fuel mixture when on petrol so this leaves the temperature sensor, possibly the throttle plate/body but you have replaced this and air leaks as well as checking the fault code from the engine management light. You might also check at a Citroen dealer if the ecu has any updates that have been issued in case it is a software problem but since the problem has only been for the last 2 years this may not be relevant.

[pehorunkl]

In few days I will check the fault code.

Which temperature sensor should I look at? As I have donor car I could easily change it.

 

How can I test for air leaks?

 

It is interesting that when driving on highway soon enough and on higher rpm the engine management light doesn't turn on until driving at 2000rpm.

 

Sometimes the engine goes out when at slowdown I press clutch and brakes from higher rpm.

 

Thanks in advance for further answers.

Tomaz

[paul.h]

The temperature sensor will be the coolant one somewhere on the cylinder head/thermostat housing.

 

The engine stalling when slowing down and using the clutch sounds like a problem of the throttle plate closing fully or needing cleaning to remove carbon build up. Was it a new throttle body that you recently put on the car ?

 

For air leaks, with the engine running, you could try using a pipe against an ear and the other end move it around the air inlet ducting/manifold to see if you can hear anything.