Poor tickover?

I've been messing about with my Landies 2.25 engine trying to get it to run a bit better. I've replace a knackered distributor cap and fitted NGK plugs. I've been ajusting the tickover screw and mixture control screw on the Zenith carb so that it's running on a fast tickover, to try and stop it stalling at lights/junctions now and again. I've got a fancy it may be mixture related although I've turned the screw right in and back out 2 turns as a starting point.I also wondered if a worn carb mixture jet would mean I would have to weaken the mixture a bit?
When I rev it at the throttle lever it sounds sweet but on the over run it's popping slightly and it never seems to idle at the same revs each time I do it?
I have a new set of points and condenser to fit yet, but do you think this would help the tickover at all? Could the ignition timing being slightly out give me these symptoms?

I intend changing the points and having a wee bit of a twiddle with the timing anyway, but just wondered if anyone else had experienced these problems?

You mentioned changing the dizzy cap. Just wondered if you changed the rotor arm as well? I would fit the points and condenser to eliminate them from being the problem. It will not be a sliped timing belt as the 2.25 petrol has chain driven timing and if it is going to do anything at all it will just snap and then you wont have any tickover of any kind (Dead engine). Set your tappets up and then when you have finished your ignition service have the vehicle tuned at a garage with a gas analiser so they can set it up properly. Failing that working you either have a worn dizzy, worn carb, knackered plug leads/coil or the valve seats could have had it from running on unleaded. Another thought (In line fuel filter b4 the carb?)

Quite a few possible cheep fixes. Get them out the way first and go from there. Ive put a link below taking you to Paddocks 2.25 ignition section... Lead set £4 coil £6 In line fuel filter £1 Failing that a dizzy costs £20 alough cheep will mount up quickly.

- Engine

Hope you find the problem soon as there is nothing worse than driving round in a car that you have to tap dance on the peddles just to keep it going. Good luck

you may wish to test the compression, uneven pressure also causes odd tickover

also dont dismiss the possibilty that the timing chain has stretched, this also causes an inability to get the timing set correctly and reliably - i spent a couple days trying to get a 2.25 to run well acrosss the rev range only to find that the chain had stretched

Disco Inferno said:

You mentioned changing the dizzy cap. Just wondered if you changed the rotor arm as well? I would fit the points and condenser to eliminate them from being the problem. It will not be a sliped timing belt as the 2.25 petrol has chain driven timing and if it is going to do anything at all it will just snap and then you wont have any tickover of any kind (Dead engine). Set your tappets up and then when you have finished your ignition service have the vehicle tuned at a garage with a gas analiser so they can set it up properly. Failing that working you either have a worn dizzy, worn carb, knackered plug leads/coil or the valve seats could have had it from running on unleaded. Another thought (In line fuel filter b4 the carb?)

Quite a few possible cheep fixes. Get them out the way first and go from there. Ive put a link below taking you to Paddocks 2.25 ignition section... Lead set £4 coil £6 In line fuel filter £1 Failing that a dizzy costs £20 alough cheep will mount up quickly.

- Engine

Hope you find the problem soon as there is nothing worse than driving round in a car that you have to tap dance on the peddles just to keep it going. Good luck

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Hi, and thanks for the reply! Just out of interest I did change the rotor arm when I changed the dizzy cap. I have been mucking about with the ignition timing solely by loosening the distributor bolt and advancing or retarding it until it sounded OK. As you say though until I fit the new points and condenser and make sure the points gap is right, I can forget about the ignition timing!
I personally think that it's a lot of little problems combining to make a bigger problem!

Sean said:

you may wish to test the compression, uneven pressure also causes odd tickover

also dont dismiss the possibilty that the timing chain has stretched, this also causes an inability to get the timing set correctly and reliably - i spent a couple days trying to get a 2.25 to run well acrosss the rev range only to find that the chain had stretched

Click to expand...

Thanks Sean

I've bean doing a bit reading up and realise now the stretched timing chain scenario is quite a common fault. As you say, I might drag out an old compression tester I have lying around somewhere and give it a go! Cheers