At - 20° C coolant temperature the auxiliary air slide must
be fully opened, and at + 70° C it must be closed.
a) Cold engine only starts with throttle butterfly open:
1. Air filter very badly clogged.
Remove air filter (1) - engine must run smoothly without
throttle butterfly being opened.
2. Control piston stuck - remove auxiliary air hose from air
collector. Engine speed must increase considerably.

b) Warm engine - idling speed too high:
1. Control piston (2) does not close properly- seal auxiliary air hose
entirely by means of clamp, clip, etc. Engine speed must decrease.
2. Air entering ar wrong place either in intake section or vacuum section. To
find the leak faster, spray oil onto all flange and hose connections (one after the
other). When spraying oil onto the leak, the engine speed will change.