mixture screw fell off inside airbox

a1quattro · 24-09-19, 02:59 PM

hi trying to get my 1984 2ltr coupe gt running , after recently giving her a full service including new fuel pump and filter ,cam belt water pump .Had played with mixture screw before all this work carried out , to get her threw mot , TODAY I couldn't seem to get 3mm allen key to do anything , so have just removed metering head lid off airbox only to find the mixture screw sat in bottom of airbox . . I spent 2hrs trying to wiggle it into postion onto end of allen key but I just cant seem to get it to screw back into bottom of metering head , very very fiddley , any suggestions

tractor Dave · 24-09-19, 06:24 PM

You can use some grease on the screw to help it hold in position. Don't be tempted to turn the metering head up side down! It will be full of crud that will enter the system.

larry49 · 25-09-19, 07:10 AM

I would remove the fuel distributor leaving the lines attached, you will have a lot more room to see what you're doing. The screw has a very fine thread which you need to be careful not to cross thread.

BackintheFold · 25-09-19, 08:42 AM

Quote:

Originally Posted by tractor Dave

You can use some grease on the screw to help it hold in position. Don't be tempted to turn the metering head up side down! It will be full of crud that will enter the system.

+1 for "do NOT turn it upside down"

Groundhog · 25-09-19, 01:15 PM

Why do you think the meter head should not be turned upside down? If a meter head is ‘full of crud’ then one has got some very serious problems with the fuel system. In fact if you are going to detach the meter head from the air flap housing I would strongly advise you do invert it in case the central plunger drops out. Also if the adjusting screw has fallen out simply putting it back is not enough of a fix, one needs to ascertain why it fell out in the first place. In the absence of any background information and without a visual inspection I would consider the option of a replacement air flap housing. In truth I am struggling to work out how it came to ‘fall out’.....interesting.

BackintheFold · 25-09-19, 01:26 PM

Turned mine upside down once.
Didn’t like how it totally fukkced up the whole “being able to drive the car” thing.
Of course, YMMV....

a1quattro · 25-09-19, 08:36 PM

The screw fell into airbox , as said before it was adjusted by mechanic [friend] at garage welst having mot , on way home it went ok but kept flooding up When pulling up and stalling , then very hard to restart . so I played with screw ,i didn't do my home work first . i.e I turned it a lot . not the fine adjustments req . any way it didn't make much difference . I decided to give car full service , New fuel pump,filter and accumilater, cambelt water pump , oil, filter, air filter and plugs , car starts but still not running nice so opend airfilter box only to find the mixture screw loose in box, I reckon id adjusted it to the point it just dropped out . I spent 2hrs with the metering head lid lifted but all still connected trying to wiggle the screw back into position and on to the 3mm allen key which I managed 3 times, but even with the flap arm pushing the screw into its postion I could not get it to wind back into the threaded hole welst turning allen key . it just dosnt seem to want to bite , . thread still looks good .

24-09-19, 06:24 PM	#2
tractor Dave Senior Member Classic Audi Club Member Join Date: Apr 2018 Location: Wales Posts: 1,157	You can use some grease on the screw to help it hold in position. Don't be tempted to turn the metering head up side down! It will be full of crud that will enter the system.

25-09-19, 07:10 AM	#3
larry49 Grown up member Join Date: Feb 2018 Posts: 44	I would remove the fuel distributor leaving the lines attached, you will have a lot more room to see what you're doing. The screw has a very fine thread which you need to be careful not to cross thread.

25-09-19, 01:15 PM	#5
Groundhog Grown up member Join Date: Nov 2009 Posts: 143	Why do you think the meter head should not be turned upside down? If a meter head is ‘full of crud’ then one has got some very serious problems with the fuel system. In fact if you are going to detach the meter head from the air flap housing I would strongly advise you do invert it in case the central plunger drops out. Also if the adjusting screw has fallen out simply putting it back is not enough of a fix, one needs to ascertain why it fell out in the first place. In the absence of any background information and without a visual inspection I would consider the option of a replacement air flap housing. In truth I am struggling to work out how it came to ‘fall out’.....interesting.

25-09-19, 01:26 PM	#6
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	Turned mine upside down once. Didn’t like how it totally fukkced up the whole “being able to drive the car” thing. Of course, YMMV....

25-09-19, 08:36 PM	#7
a1quattro Grown up member Classic Audi Club Member Join Date: Mar 2013 Posts: 251	The screw fell into airbox , as said before it was adjusted by mechanic [friend] at garage welst having mot , on way home it went ok but kept flooding up When pulling up and stalling , then very hard to restart . so I played with screw ,i didn't do my home work first . i.e I turned it a lot . not the fine adjustments req . any way it didn't make much difference . I decided to give car full service , New fuel pump,filter and accumilater, cambelt water pump , oil, filter, air filter and plugs , car starts but still not running nice so opend airfilter box only to find the mixture screw loose in box, I reckon id adjusted it to the point it just dropped out . I spent 2hrs with the metering head lid lifted but all still connected trying to wiggle the screw back into position and on to the 3mm allen key which I managed 3 times, but even with the flap arm pushing the screw into its postion I could not get it to wind back into the threaded hole welst turning allen key . it just dosnt seem to want to bite , . thread still looks good .