Fuel Mixture Adjustment (Afm Allen Screw)

[Phil205 1 1 Cars]

Symptoms :-

Car idles ok in neutral.

Car bunny hops for 1st mile or so, then is ok.

Poor fuel economy - say approx 280 miles per tank - used to get more miles (on long runs).

 

 

Recent History :-

Garage fixed bad idle by adjusting fuel mixture - the allen screw had worked itself loose (apparently).

 

 

Question :-

Can I adjust the fuel mixture myself without a meter ?

e.g. Could I try adjusting the allen screw by a quarter turn either way and see if the fuel economy improves or am I likely to make things worse ?

 

[Anthony 1,003]

That screw only controls fuel mixture at idle (in effect it's a tiny air bypass to allow some air past the metering flap, thus altering the mixture), so the chances are that you've got other issues - possibly a duff AFM, or possibly an engine that just needs setting up properly in terms of ignition timing, TPS positioning, checking ECU temp sensor is reading properly etc.