Running Rich

[davey sprocket 14]

My standard 1.9 has been running rich pretty much since I had it, which isn't great for fuel consumption but I do limited mileage, so kinda put up with it.

However, she's failed her MOT on a couple of bits today, including the CO being 3.6... just over the 3.5 limit.

 

Now, I've been through various things on the car during my 3yr ownership.... what could I be missing??

 

Was running like a bag of nails when bought due to various air leaks including the classic bolt missing from the inlet manifold. Happy that there are no air leaks now.

 

Have cleaned out all the hoses, oil filler tower etc.

 

SAD is good... I rebuilt a spare one and installed that, although it has to be said the original I took off turned out to be fine.

 

ECU temp sender. Brand new one bought from Pug and fitted.

 

Tried another AFM. No different whatsoever. Suppose it's possible the spare was just as bad as mine?

 

I've gone through the throttle/ idle set up as per Haynes.

 

What else can I check... I was under the impression the adjustment screw on the AFM only adjusts the mixture at idle?? Could it be injectors needing cleaning??

Sorry if I've not done much searching.... am at work and a bit despondent at failed MOT!

[welshpug 1,657]

check that all the parts are matching, i.e all 1.6 or 1.9 bits.

 

that co reading is at idle, so tweakign the afm will sort it if the temp sender is good.

[davey sprocket 14]

check that all the parts are matching, i.e all 1.6 or 1.9 bits.

 

that co reading is at idle, so tweakign the afm will sort it if the temp sender is good.

 

Thanks WP.

 

Yep, all parts are 1.9 bits.

 

You're right.... of course it's at idle. Presumably if I tweak it one way the revs will rise and the other they'll fall??

Seem to remember being shown a trick where you let a bit more air into the inlet and it revs rise it's too rich, if they drop it's too weak??

 

I'd rather spend the evening tinkering than searching for answers online

[welshpug 1,657]

best to pop round the local garage tbh and see what happens when you tweak the screw.

[Miles 331 1 Cars]

Either tweak the AFM mixture screw but really the MOT place should or can do this when being tested or just turn the idle upto around 1200rpm which is allowed on older cars too

[davey sprocket 14]

Either tweak the AFM mixture screw but really the MOT place should or can do this when being tested or just turn the idle upto around 1200rpm which is allowed on older cars too

 

Thanks Miles, I'll wind it out a bit and if it doesn't pass, get them to tweak it on the analyser.

 

Emissions look like least of my worries now, having spent the evening tinkering with the rear brakes and shearing off not one but both the bleed nipples. PM coming your way.

[mikeygulley 19 1 Cars]

Mine failed on the same thing, the MOT tester adjusted the screw on the AFM but it didn't make much difference so he took the black cover off and adjusted it inside. He did mark it where it was before he moved it but I never moved back because it ran fine.

Edited June 14, 2011 by mikeygulley