BX16V.com Forum

As the previous owner of my valver changed the settings of the air flow meter adjustment screw i'd like to set it back the way it should. Does anybody know the exact citroen procedure to set the AFM screw on a valver?

Chuck it in the bin and get another

That screw does not count for the DFW 148bhp engine. The engine management does not take it into account.
It works as CO pot only in non cat versions.
I know as I have one of each...

yes I'm looking for another AFM... CO is much too high to pass MOT

anybody more suggestions for the high CO?

ECU has 2 errors in it code 31 and 51 (ecu light sometimes lights for a minute or so). Most of the time the lights goes on when driving on the highway for about 10minutes. Can get rid of it by switching off the ignition after a minute or 2 of driving with the light on and then starting the car again. Errors stays away then for the rest of the day. Switching the ignition off and on directly as the lights comes on doesn't work. Errors stays there then. Just keep driving on the highway with the light on doesn't work either the light then can stay on for miles and miles. When driving in the city the light sometimes comes and goes by itself (not very often). If the ECU lights on when parking the car for a night it's still on the next day with cold start and driving the first 5 miles.

engine already has fresh spark plugs, new air filter (and new gearbox thanks to Mark who supplied the new box)

When the light's on the engine doesn't run different. I suspect the AFM at this moment or mayby the lambda. Not sure about the lambda though. Car has done about 128,000 miles

hope you can help me out

Codes 51 and 31 are related.
51- oxygen sensor
31 - mixture regulation auto adaptation

So I think the lambda sensor is gone...

I've had this problem (on a none cat) where a friendly garage tried to adjust my fueling up and simply adjusted the AFM to death. Only just managed to get it started / running long enough to get it hope and go on the hunt for a replacement AFM.

If it is just the POT setting that is wrong, could you not measure the resistance of another POT and set yours to match?

I don't think it's just the pot setting. CO was really way to high and adjusting the AFM with the CO meter didn't result in anything good only thing that changed was the ECU light going on think mine really died.

Thinking about changing the AFM for sure and the lambda most likely as well .

About the AFM setting procedure also for the phase 2 148bhp there is a citroen procedure just as there is for the 160bhp (that's what they said at my garage tonight) only problem is my garage doesn't have the 16V add-on with phase2 in his citroen manuals

do you know which set of manuals they have (numbers wise), i dont think there is much if anything covering the AFM setup in the standard manuals, i suspect it would be a technical bulletin. I might have in amongst the manuals i have, if i get chance i'll have a look this evening. I would certainly be interested if its there.


Just out of interest, have you tried adjusting the rather big cog underneath the black cap on the AFM. I've used that before to increase fueling, it adjusts the spring rate on the variable resistor, anitclockwise to richen.

in my dads workshop manuals they basically say 'under no circumstances touch that bloody AFM"

Yeah reckon the technical bulletins might be the go

NZ16v wrote:in my dads workshop manuals they basically say 'under no circumstances touch that bloody AFM"

Yeah reckon the technical bulletins might be the go

Hence my first statement, "Bin It"

yep well if you touch it, it doesn't work if the AFM is already broken

anyway I bought a brand new original AFM on ebay few days ago hope to receive it soon!!! and indeed I won't touch the bloody screw

hope this solves my problems. Keep you posted.

take the back box off, shuv some socks up the pipe re-fit it and it will prolly pass the mot

jayw wrote:

NZ16v wrote:in my dads workshop manuals they basically say 'under no circumstances touch that bloody AFM"

Yeah reckon the technical bulletins might be the go

Hence my first statement, "Bin It"

Well, bought a new AFM mounted it and still no luck. Next one is the lambda. Have a new one now going to mount it soon + a new exhaust kit

well as said brand new AFM mounted and just a few hours ago a new lambda still no luck this baby is trying very hard to make it very difficult!

the next one I'm going to replace is the exhaust kit (behind the engine the piece connecting the exhaust manifold to the exhaust).

Mayby you lot have more suggestions about which sensor to test or have a look at? AFM + lambda have been replaced and still the error stays. What can be wrong? the seal from the inlet manifold?

Check all your earths, clean and/or replace, and also, pull off the fabric tape and go through the injection loom, looking for breaks-any shorts will ruin the idle etc.

Dont reckon its a particular part, sounds more like a 20 year old car with a bit of an electrical fault.

Doin the above is free too!