Petrol Starvation ?

[124cso]

My A/C 650 has developed a problem which I think is fuel related.
I drove into town tonight and all was fine. Parked for about an hour and then came home. Basicly as soon as I got going, it was stuttering and lacking power to point where it would idle but die as soon as I put it in gear and tried to move. Eventually got home by crawling at 20K in second. It would just not accelerate/ just died if I tried. Fuel level was low so added 10L but no change.

I have searched a few old threads and have 2 ideas.
I see that the pump actuator rod wears and gives a problem when hot ? Anyone know what rod length should be ? is it easily removed to check ?
My pump has a crimped body ( no screws to pull it apart). Are these serviceable or replace only option ?

[KAL SPL]

Pull the fuel line off the side of the carby and then crank it over see how much pressure there is coming out of the hose.

I think it may be more spark related , check the earth strap to engine isnt loose.

[Rusty's Uncle]

Could also be loose carb mount or leak at base of carb

[ChrisRLewis]

Perhaps if the fuel level was low, you have dragged muck and rust up from the tank?  If so this may cause a blocked carb jet?
Check the petrol level in the carb, which will then give you an indication if the fuel pump is playing up or not.
p.s always worth fitting an in-line fuel filter

[124cso]

Perhaps if the fuel level was low, you have dragged muck and rust up from the tank?  If so this may cause a blocked carb jet?
Check the petrol level in the carb, which will then give you an indication if the fuel pump is playing up or not.
p.s always worth fitting an in-line fuel filter

 Tank was cleaned out recently for that very reason. I fitted an inline filter as soon as I got the car, that is how I knew to look in the tank, but filter sock in top of carb looked clean.

[124cso]

I've checked earth strap, pulled off carby & stripped out all but choke plunger mechanism. Gave it a good spray with CRC carby cleaner, cleaned what looks like metalic flakes out of air emulsion tube (goodness knows what that is for) adjusted float level to setting in book(7mm) and back on with new gaskets.
Runs lots better but occasionally (intermittantly) stalls / loses idle at intersections/roundabouts and 'hunts' / 'surges' on the over-run. Re-adjusted float back up to 6mm instead of 7mm. Idles better but still too fast (?) and runs quieter with air mixture screw out about 4 full turns.
I almost think idle circuit is not working ? Still 'hunts' / 'surges'
Jets seem all clean now but I do not know what condition their seats in the body may be in.

[thepuddlejumper]

Air mixture screw should not be 4 turns out if I remember correctly it should be 3/4 turn 1 1/4 turn max. Anyone confirm this?

Ralph

[1973/126]

 I read somewhere on the net it`s 2 turns on the 28IMB. I would also replace the rubber seal on it.

[KAL SPL]

Did you fit all new carby gaskets while you had it off ?
the gasket on mine between the base of carb and the bakelite plate decided to suck in at 1 spot and would never idle properly.

[124cso]

I read somewhere on the net it`s 2 turns on the 28IMB. I would also replace the rubber seal on it.

The books say start at 1 & 1/2 turns and go from there but I found it runs smoother / quieter way out at about 4 for some reason ! ?

Fitted all new gaskets from the top of the head up. Even faced off the bottom of the bakelite spacer/drip tray with 600 paper on a milled surface block.

I note however that some of the carbs on ebay seem to have a gasket behind the choke body. Mine had nothing and not one in the carb kit