MPG

[Dadad]

Way2go

Took your advice and went back; he agreed that the current CO figure could result in a too lean mixture, overheating and increased bore wear.

He used the bleed screw to give a new figure of 1.2% but said he couldn't get it any higher, perhaps to 1.5%, just by using this method, although he had used it to reduce the figure from the original very very high reading.

What else can he do ?

Fuel consumption much better; fuel guage not down to 1/4 yet, although mileage is over 250.

[Tinkley]

FWIW on my carburated models 150C and XU52C engines the actual MOT readings are/were around 0.15% CO somewhat down on the official Citroen figures in the region of 1.5%. One regular station that tested the 14 said the engine would blow up - it did'nt and remained the same until end of life (175k) - she wasn't going to pass with a blown head gasket...
My gut instinct is that the official figures allow for lightly rogue engines and are well inside the permitted levels of the day. Peugeot themselves were very keen advocates of lean burn technology along with a few others and against CATs' as they believed the levels could be achieved without that extra power sapping addition and complication.

[Tim Leech]

Maybe he has wound it down too much, had the same issue with a 16TRS once, the technician fiddled with the carb to pass its MOT but went too far and it was like a snail!

[Dadad]

Way2go

Took your advice and went back and he agreed that 0.76% could lead to overheating and premature bore wear. He adjusted it to 1.2% but couldn't get it any higher, using the bleed screw. No action on ECU. Still don't know if it's Jetronoc or Motronic. Running well with much better mpg.

[Way2go]

1.2% should be good enough I would think. Very strange though that previously this could have gone to 3.5% on the same screw.

Easy to see whether you have the Motronic 3.1 or the Jetronic with a quick squint under the bonnet. The Motronic does not use a distributor as it has a dual coil pack working on the wasted spark principle. The air filter base will also not contain the air-meter of the Jetronic as the Motronic uses the advanced MAP sensor technology.

[Dadad]

Way2go

Took your advice and went back; he agreed that this figure could lead to overheating and increased bore wear. He used the bleed screw to get it up to 1.2% but couldn't get it any higher.
It seems to be running well with very much improved fuel consumption.

Thanks for your advice.