pierburg problem.

[kevtherev]

If I snap the throttle open the engine hesitates. (and sometimes stalls)

If I gradually depress the accelerator there is no hesitancy

what could be causing this?

[Grun]

Kev

Accelerator Pump

Mike

[beachiain]

when it's wam or cold? Mine's like that when it's cold, think my carbs needing some tweaking, think it's flooding a bit with the choke.

[Mocki]

are you telling us everything Reverend?
like is this on LPG, or fools gold?

warm or cold engine?

[SyncroRich]

Possibly split accelerator pump diaphragms.

They should give an extra squirt when you depress accelerator to account for the extra air going in.

If they're split the engine will run a little lean for a second.

Pop the filter off and have a look into the barrel of the carb while someone presses the accelerator (engine off) you should see the squirt of fuel.

Either that or you have a poor spark.

[SyncroRich]

too slow

[kevtherev]

oops sorry.
yes warm or cold on fools gold

I've had the little pump off..the mechanism works.
the diaphragms look in good shape.
the inlet from the float chamber is free from blockages.

but I have not checked the squirting

and I get a hard acc pedal when trying to snap the throttle open

[T'Onion]

vac pipes ok ?

[Mocki]

so it is ok on LPG?

if its ok on lpg, but crap on fools gold, then its quite prob isnt vac pipes, and more than possibly is fuel starvation...... is the cut off solenoid working and not stuck( on the carb, not the petrol switch off solenoid on the LPG sys)

[HarryMann]

Mine's like that when it's cold, think my carbs needing some tweaking, think it's flooding a bit with the choke.

.. it could equally be weakness when it's cold (but then one doesn't snap the throttle fully open when its cold anyway, does one )..

Diff between hesitating due to weakness and richness is that the former you should hear inlet air roar, or if very low revs, 'pobbling' (classic weak misfiring), or the latter, due to richness, complete cutting out.

And then there's the case when there's simply insuffient airflow with choke when cold (due to strangulation), which implies richness but in fact is simply... insufficient airflow!

Carburrettors can rarely cope with the full range of throttle demand, snap openings etc. through a full range of temps from very cold to hot, at some point the choke should be off when its on and on and when its just clicked off... even multi-stage chokes. Unless it's totally undriveable, or dangerous pulling out, expect to nurse it a bit at some stage when its warming up... another reason for the advent of fuel injection on all but the cheapest cars.

Good carb-heat also helps during the warming up stage.

[T'Onion]

so Kev , i take it you've sorted the water in the tank problem ?

[HarryMann]

and I get a hard acc pedal when trying to snap the throttle open

Is that not binding at the pedal-end push-rod pivot assembly, or in the cable run Kev? After a wet salty winter, such things might be worth checking out...

[kevtherev]

Ah no I haven't sorted the water problem... just drained the tank and put fresh in...ran it through using the gas to pump it.

yes no bother at all on gas..snap the acc on gas and she bellows like a cow..
pedal is fine too, no hardness to it ever.
but on petrol..if I pump it the pedal goes half way and gets harder to press...then if I press it slowly it feels fine and the engine revs rise fine

how does one check the shut off solly Steve?

My thoughts are the squirter pipe is blocked...and it causes the hard pedal.

I will check out the squirtings tomorrow

[sevy]

I know a few sites that show squirting problems !!!

Ref water in tank check the rubber neck for splits mate !!

[Mocki]

oh, well, the float chamber and jet is full of crap then.........

that £20 would have been better spent on beer Kev....and you would have got more gallons too.........

take the solenoid out, and apply elastic-trickery to it, you will see if its working........