CO % ??

[Mike E (uk)]

Hi what should it be for non cat cars?

Mine is currently 1.9%, but the exhaust smoke still stinks.

One data sheets says 1.5 to 2.0
another says 0.8 to 1.5%

Mike

[Anonymous]

Hi Mike,
I always thought it was the latter.

Cheers

[Toddman]

Yes 0.8 to 1.5 is also what I have down

http://www.bx16valve.co.uk/17.html

Cheers
Luke

[Anonymous]

This adjustment affects the %co only at idle idle speed ??

[daaristieweer,wiedurft]

yep, because the ecu is controlling in a special map the idle speed, ignition and throttle by ISCV.
greeting, jonne

[Mike E (uk)]

Still can't get the idle mixture right.

The exhaust gas is smelly, and the CO wanders around between 1.6 and 1.9% no matter where the adjustment pot is set.

Engine idle is lumpy and misses. I expect the plugs are fouling up.

Dodgy AFM? anyone local to me able to lend me a known good one for an hour please?

Will check idle valve, idle switch, hoses (again)

Any other ideas?

thanks,

Mike

[Toddman]

Worth checking the temp sensor outpits just in case the ecu is reading duff info - I remember a mate with a R19 years back had no end of trouble and it turned out to be a badly corroded temp sensor confusing the ecu.

I have an almost new AFM if you fancy a daytrip Mike

Cheers
Luke

[ollie]

Other small point - a CO meter measures just that! what the HC level like? It could stink of unburnt fuel from a missfire and still burn the rest quite nicely

[Toddman]

Also if oyu are running a chipped ecu I would try it with a std one just to be sure it isn't the map.

Cheers
Luke

[Mike E (uk)]

Thanks-I will check as suggested.

Your offer of an ECU swap may well be what I require-thanks Luke.

I will see how I get on next weekend with it.

Mike

[Mike E (uk)]

The AFM was at fault.

The AFM measures the air flow by the simple device of a potentiometer with the wiper fixed to the flap. When the engine runs, the wiper moves up and down on the carbon track, and the voltage from the wiper fed back to the ECU to set the amount of fuel injected.

On my car, the carbon track was worn, which made the idle hunt and misfire, and gave a very smelly exhaust. It also run lumpily at low throttle settings.

You can test for this by removing the AFM lid gently pressing down on the wiped while the engine idles, and see if this smoothes the idle.

I have now put a CO meter on the exhaust, and set the adjustment potentiometer to 1.5%.

The idle is now very smooth, and the engine runs much smoother at low speeds.

I hope this post helps other people with the same problem, which is likely to occur as the AFMs get old and worn.

Mike

[thanuttiscotsman]

hi there,
well then thats probally the problem with my car then. as the symtoms are the same. although my afm is a re-con and it cost me 205 quid im sure your probally right, mine is probally knackard too. as my exhaust is smelly idles high and when i start the car it does all this revving up by itself, revving prolly cos its trying to get a reading from the afm.

cheers rossco

[Toddman]

Mike how did you fix the AFM?
Was it by retracking as I described in an older thread or by replacement?


Would be nice to know if the retracking method does actually work

Cheers
Luke

[Jezziebx16v]

I'd be interested to know how you sorted this aswell Mike.

Jez

[thanuttiscotsman]

hi peeps,
well i have the same problem and what im going to try in about 1 hour is using 1500 went n dry and im going to rub down the carbon track to remove the shiny smoothed worn part where the track runs. im sure the rest of the surface is slightly rougher compared to the worn line and im sure rubbing down 1 micro milimeter wont cause problems as the layers or thickness i dont imadgine will affect the workings. i will report back later.

cheers rossco