340 1.4 running like a B.O.S

[bendy9891]

can you help please,

my 1.4 340 has recently given me a headache.
it runs fine cold, but as soon as it warms up it will cut out at most junctions i come too.
when driving along, lets say in 5the doing 40mph and try to accelerate slowly thee engine will bog down and die
giving no power at all. however at theis point if i take my foot off thee power and theen try to accelerate again
its fine.

i have taken thee carb apart, cleaned everytheing, checked diaphragms, and put back togetheer. no change
ive recently repaired thee brake servo hose, as it disintegrated.
and thee plugs and leads were replaced not to long ago. after one spark plug melted a little bit.
my 340 gets a lot of abuse from my right foot.
the vacuum pipe for thee breatheer theat goes to thee carb sandwich plate has been blocked off.

any ideas?

[mrsoundcraft]

Not sure but Ive got similar issues. Maybe we can work it out together??

My car sometimes does a thing where you have to keep your foot right down on the throttle, any less and its like the brakes are on, it also sounds a lot like a lawn mower when Its doing this. If you put it into neutral it stalls and thats it. a few minutes later and its running fine.

Ive been down a similar route to you. I was suffering a vacuum leak which I sorted out. Ive also changed the leads and plugs and looked at the carb.

We may have different problems but Im starting to think I need to look to the ingnition system.

[jon-ovlov]

Whats the idle solenoid like on the carb? Could do with a clean. I had an idle problem, turned out to be that.

[bendy9891]

ive had a good look at, and cleaned the idle solinoid it seems to work fine. thanks for the suggestion
im too now thinking this could be an ignition problem,
but where to start

[volvosneverdie]

Check all the ign parts. Might as well.
And check theres no air leaks along the carb base if you havnt already.

Is there any moisture/oil in the dizzy?

[morgan105]

I'm not saying this is both your problems but could well be worth a check as I have had it happen to me and I know others with the same problem take their cars in to the shop and eventually the mechanic found it.

Take a look at the small filter that is located on the end of the fuel pick up tube and the end of the pick up tube itself located in the tank. The filter is only plastic and can sometimes when it wears can crush itself over the end of the pick up tube when hard on the throttle which shuts off fuel supply. If suspect remove this and put a inline filter in to the fuel lines in the engine bay. You'll know by pressing the filter between your fingers whether it is crushing itself because it should be solid.
If the filter is fine make sure the end of the pick up tube is cut to a 45 degrees angle because if it's straight cut the filter may be sliding a small amount closing of the fuel flow, the angle cut in the tube takes care of that problem.

When the engine shuts off the filter has time to move away from the inlet and gets you going again, but when you get going again in time it will start to crush again and block off the fuel.

This happened with my old car and my wifes 340. Hers only wanted the tube cutting as it was parallel to the filter but it was the filter on mine that was causing the problem.

Once that is checked then check the filter in the fuel pump.

Make sure your emissions are correct as well, if it's to lean it can cause stalling when slowing down.

[bendy9891]

not to sure if its ignition know. drove to college this mornin, only started playing up on the last few junctions
put the choke on a bit and it fast idled fine but come to a stop behind a car parking and it died, couldnt stop it
and it was a pain the arse to start again it took a few attempts. but i noticed the valves sound like there clattering a bit.
Could really bad clearances be affecting my engine this much?

[morgan105]

If they are really bad it would'nt help. Check those first and set them if needed.

If you have the normal coil type ignition (round tube type), not renix (small box type), after you do the valve clearances check points gap and the timing.

Valve gap could be getting to wide as engine heats up.

Best setting them when cold but can be done hot but they will be cooling as you go. I always set them cold as gap can't shrink anymore.