Engine shake & running rich

[schnaarf]

Its a never ending list with this car - probably something to do with it having 260k. I will persevere.

When starting from stone cold, it idles really well for about 20 seconds then the idle gets progressively lumpy which can be felt in the car as it warms up. At idle, it probably happens about 1 or 2 times per second. Also lumpy off idle.

Its also running rich and seems hesitant to come off idle. Idle is around 7-800 and stays there perfectly - the lumpiness doesn't register on the tacho

I've checked:
- blue temp sensor (at ecu, cold and hot)
- tps: clean as a whistle inside and checked pins for idle, off idle and wot continuity or not
- icv: cleaned and moves freely
- afm: adjusted the wiper to fresh part of the track
- c191 plug clean

Does this sound like an intake, fuel or timing problem?

[Brianmoooore]

Any lambda sensor on this?
It sounds exactly like a blue temp. sensor/c191 problem, in spite of the checks you've done, so I suggest you go back over that again.
It's not the C191 plug and socket that gives problems exactly - it's the wires to the lower half, which corrode near their ends, inside the insulation.

[schnaarf]

No lamba sensor.

Rechecked the ecu reading from the blue temp sensor: 3490 when stone cold and went down to 700 when warm- will recheck the warm reading again later when I go out. Plug was dry and zero corrosion - reading were identical at the sensor and ecu.

Look at the screws here- if someone has buggered about with it, could that be the issue?

[Speedtouch]

Could well be; look at the dirt lines on the butterfly disc itself, which suggests it may have been put on at the incorrect angle, resulting in a slight gap which you can apparently see to the top right of the disc - this would let excess air though at idle, and would not seat properly in the throttle body.

You would need to slacken the screws a bit, then re-position the disc, ensuring it fully closes with a good seal all the way round with the throttle closed.

Also check the adjustment of the throttle cable, ensuring there's enough slack to enable the butterfly to fully close, but also to fully open with the pedal held to the floor.