Fast idling

Post by **iddy** » Thu Nov 13, 2008 5:03 pm

I haven't driven the Minor for a few weeks (although my wife has), and noticed yesterday that the tickover is too fast.
I've made sure the choke cable is closing properly at the carb, so now want to adjust the tickover. But before I do, is there any reason why the tickover would increase, bearing in mind nothings been done to the car?

iddy

Post by **Dominic** » Thu Nov 13, 2008 5:09 pm

Do the linkages need lubricating? Also, is the dashpot filled to the correct level with correct type of oil?

Post by **iddy** » Thu Nov 13, 2008 5:24 pm

Dashpot has 3 in1 oil and everthing seems to be free.

iddy

Post by **PSL184** » Thu Nov 13, 2008 6:20 pm

Sticky carb piston..... Take the 2 or 3 screws out and remove dashpot and piston. Take care not to bend needle! Clean everything throughly with carb cleaner noting any stuck on gummy deposits and put all back together and see if tickover is back to normal. If its just slightly sticky it could be holding the needle up far enough to just give a faster idle - if it sticks any more the car would stall and not idle correctly. Its also possible that you are running slightly rich so look at this after you have cleaned everything out...

Post by **iddy** » Thu Nov 13, 2008 8:09 pm

Cheers,
Will give it a bash this wekend.
iddy

Post by **bmcecosse** » Thu Nov 13, 2008 9:34 pm

Maybe just the engine has freed off a bit. Have you tried simply backing off the idle screw ? Could also be that the throttle cable is snagging slightly in it's outer sleeve - or the return spring has lost some tension - or just maybe when the throttle is pushed right to the floor - it's bending the bracket that holds the outer sleeve, and so it has moved back a little. Check the throttle has just a little free play when it's at idle. I would look to all that before getting into the carb dashpot!

Post by **jaekl** » Thu Nov 13, 2008 9:43 pm

Any chance of a vacuum leak? Hose came off or cracked.

Post by **mike.perry** » Thu Nov 13, 2008 9:49 pm

Make sure the 2nd screw is clear of the cam then turn the tickover screw back until you have the desired tickover speed. Adjust the 2nd screw back again until it is almost touching the cam.
If the engine runs ok leave well enough alone. There are no engine management systems on old cars so they tend to do their own thing.