Engine stalling. Possible mixture problem?

[simonloring]

I recently took my saloon to the garage to have the head gasket replaced, and apart from that issue it was running well and starting 1st if not 2nd time, even in cold weather. However, on getting my moggie back from the garage it struggled to start taking around 10 attempts. It also began to chug and eventually stall when i slowed in traffic or had to stop at a junction. Last week I took the car back to the garage to have a new radiator fitted, (not causing a problem but one of those things which just needed doing at some point). They took a look at why the car was running badly and said that when they replaced the head gasket it was running rich and that they had weakened the mixture. It is still struggling to start however, and when moving slowly, the engine seems to be revving too fast with the choke out and stalling with choke in.

If anyone could suggest what the problem may be and how I could remedy it I would be most grateful

Thank you
Simon

P.S. It is a 1098 engine if this helps in any way

[aupickup]

posssibly running to lean or to weak

was the timing ok when it went in to the garage

[simonloring]

Thanks for the quick reply! Timing was fine prior to being taken to the garage the first time. When i took it back second time they admitted they had set the mixture too rich but that they had weakened it to solve the problem. Still cutting out in slow traffic, especially when in 1st or 2nd gear with the clutch down.

[aupickup]

increase the tick over if mixture is correct

u should not have to use any choke to keep the engine going when hot

[bmcecosse]

And - it should start promptly cold or hot. I suggest - a nother garage that actually knows what they are doing!
Meantime - check there is some oil in the carb dashpot (hex nut on top removes the dashpot damper) - and check they have connected the choke properly - when you pull it out does it move the carb jet down ? Get someone to pull it while you watch. then - adjust when it's hot and idling. Set the idle speed to where you want it - then test the mixture using the little 'lift' pin on the carb. Raise the piston about 1/16" - if the speed increases it's too rich (wind the mixture nut UP a couple of flats) and if the speed slows it's too weak (nut down a couple of flats) - and repeat until nothing much happens ! Now re-adjust the idle speed to a setting that doesn't stall when you use the clutch. BTW - if the clutch pedal stroke is too long (not enough free play) then the clutch can put an over-heavy load on the idling engine, and don't sit with foot on clutch anyway - it wears away the carbon thrust!! Procedure for moving off must be - clutch out, into 1st gear and clutch in immediately. If crawling in traffic - you must go into neutral and release the pedal right away. Wait till there is a bit of a gap - then move forward into the gap, and back into neutral right away.

[MarkyB]

When you say

the engine seems to be revving too fast with the choke out

I've got a feeling that the garage have been using the fast idle adjustment screw to adjust the tick over.
I thought there was a gap specified for how far from the fast idle cam this should be but looking in the book it says with the choke out 6mm (1/4 inch) the tick over should rise to 1000 rpm (with the engine at normal running temp).
It may be that they haven't changed the mixture at all.
bmcecosse is exactly right about what to do but make sure this screw is not touching the cam 1st or it will spoil all the other settings.
Fast idle should be set last.

[simonloring]

Thanks for all the helpful replies. Problem seems solved now (touchwood) i've adjusted the mixture and idle speed. Started this morning first time, so far so good.