205 1,6 auto problem

[Kalkveien]

Hi

I own a 93' 205 1,6 automatic whit a XU5M3/Z/L and Maqneti Marelli Monopoint G6.

recently she as startet with something strange, at criuseing speed she runs uneven and the chek engine light comes on. When i accelerate she is just fine and the light goes away. Idle and starting is normal.

Fault code 52 comes up, and if i am correct this meens: Mixture control (MC) fault.

What could be wrong

[CitroJim]

More than likely the pipe that connects the MAP sensor to the inlet manifold. It can perish and/or block up and give rise to the exact symptoms you have...

[Kalkveien]

I just change that pipe becouse it had cracked. The problem startet at that time. Is there some way to test the MAP, hose or vauum

[Kalkveien]

And it seems to be worst when the engine is hot. The hose is a bit longer than the original, but that cant couse this problem?

[spider]

I don't think the length of the vac pipe would have much effect unless it was really long, as in an extra half metre or so. Different to having varying lengths of fluid pipes as its depression / vacuum rather than positive 'pressure'.

[Kalkveien]

- update -

The car was getting better, but still not great. I chenged from 98 RON to 95 RON a few weeks ago.

Did following this weekend:
- Cleaned all contacts related to ECU (not O2 sensor, did this not long ago)
- Cleaned and dried trottle pos. sensor and MAP sensor
- Changed all 4mm vacuum tubes
- Changed clamp on fuelhose on injectorunit
- Cleaned injectorunit
- Checked the bolts on the injectorunit
- Added a bottle of injectortreatment

So far so good, after 5 miles. Will post more updates onward