Engine dies when cold, on acceleration

[AlleyNiki]

This is a fairly recent problem: I'll let the car warm up for a minute before taking it on the road like I always do so I can have it running without choke. Upon getting onto the main road the engine will accelerate until it gets to about 2000rpm,

(in other words I can't reach upper revs, and climbing hills is impossible!)

 then the power suddenly dies off. My car behaves like this until the engine is good and hot then it accelerates normally. It only seems to do it when the car isn't yet warmed up.

I've read some other similar posts that may suggest bad carburettor gaskets, but to be honest I've not checked these yet.

The only thing I can point to is that I ran the car very nearly out of fuel the other day. Could this be a dirty needle?

Incidentally, it's a fairly new carb. It was only replaced about a year and a half ago! Any suggestions would be great, guys!

Alleyniki

[AlleyNiki]

Oh and it's an aircooled 126.

[skelz]

Sounds terminal ... I will take it off ur hands,, Dont worry I will pay the postage.. Sorry Mate I am no help.. hope one of the gurus can help !!

[KAL SPL]

I would be pulling the carby and make sure the gasket on top of the bakelite plate hasnt sucked in but that will still run crap once its hot aswell.
Theres a filter on the front of the carb to , big 17 or 19mm brass nut , check that.
Could also be timing related.

[dajwid]

Or fuel pump.

[AlleyNiki]

Cheers guys, will check both and see how I go. I think it's probably some rubbish in the carby as all this happened after I had run my fuel tank very low.

Can carbies be cleaned easily? Is there some liquid cleaner that you can run through the jets to clean them?

Alley

[AlleyNiki]

Sounds terminal ... I will take it off ur hands,, Dont worry I will pay the postage.. Sorry Mate I am no help.. hope one of the gurus can help !!

As Bit would say from Tron: 'Noooooo-no-no-no-no-no-nooo'

[KAL SPL]

Remove carby , strip down and wash each component with petrol , bolt back together and youre good to go

[AlleyNiki]

Remove carby , strip down and wash each component with petrol , bolt back together and youre good to go

Well gentlemen, I removed and cleaned the carby. No rubbish found in the jets and the inside was nice and clean.

Also, the fuel pump appears to be doing its job as I disconnected the pipe and managed to get fuel to shoot out everywhere upon turning over the engine.

The mixture adjustment screw is at the best position (for smoothest running) so I'm going to have to investigate the ignition side of things now.

Also, the problem seems to be getting gradually worse! Now the car won't reach higher revs even when the engine is hot.. Runs perfectly at idle and lower revs..

Might buy new plugs as mine are looking a bit toasted. Still getting a spark on them though.

[KAL SPL]

Is it back firing at all ?
Checked the earth strap isnt loose ?

[126redbomb]

Sorry to butt in but it sounds like your earth strap is probably frayed or loose.  Mine was holding by the last few threads and was causing havoc, acting in the same way as yours.  Also check the condition of the battery terminals.  Good luck.

[AlleyNiki]

Sorry to butt in but it sounds like your earth strap is probably frayed or loose.  Mine was holding by the last few threads and was causing havoc, acting in the same way as yours.  Also check the condition of the battery terminals.  Good luck.

Well Gentlemen, I have the beast working properly again!   

It was the ignition side of things this time! Wasn't getting enough of a spark, it seems. I replaced the spark plugs, capacitor condensor, put on new HT leads and hey presto the beast is back.

Good thing we have a Fiat 500 spares place (literally called 'The Spares Place') in South Australia.

The earth strap has been fitted on recently by me, and I know I cleaned all the gunk off it.

I don't know what the cause of the problem was, but probably a combination of all three of the components I replaced.

Thankyou guys for your time! 

Now to replace the timing chain..

Alleyniki