Technical Fiat 126 - poor running when hot

[drgreen]

Anyone help me?

I have an air cooled 126 (1983), when it gets hot the timing seems all over the place.
I've replaced points, coil, condensor, alternator because it was throwing out 15volts plus, changed condensor again, plugs, distributor cap, leads, serviced carb.
Its fine when its cold as soon as it gets hot (or at least runs for 20+ mins) it sounds like a bag of bolts, back firing and no acceleration!
Really running out of ideas now, anyone any similar experiences?

Denis

 

[Davren]

Tappets need adjusting ? --- Head Gasket ?

Dave.

 

[Panda Van]

Not sure if this is of any use, my dad runs a 126 engine in his 500, he had similar problems. It turned out to be the shaft in the distributer that opens and closes the points had worn, so no mater how well he adjusted the points after say, 20 minutes of running it would run like a bag of poo because the point gap had closed up again because of the bump on the shaft had worn down, it wouldnt be opening to points wide enough. Hope this makes sense, it is a part prone to wear. Ive given up with points etc in my 500 and so has dad, we bought one of the spangly electronic distributers each from ebay - not missed a beat since !!

 

[PandaMark]

It turned out to be the shaft in the distributer that opens and closes the points had worn... ...it is a part prone to wear.

I can concur with this. I used to run a 126 about 15years ago. I got through three of these; the original and two new ones - both of the replacements wore quite quickly too

 

[seicentom]

It's not just the thermostat that opens the flap to the right of the cylinders (as you look in from the rear) seized shut is it.

Normally they break and stay open and cause starting problems in poor weather, but it could happen the other way round.

 

[topolino2000]

Anyone help me?

I have an air cooled 126 (1983), when it gets hot the timing seems all over the place.
I've replaced points, coil, condensor, alternator because it was throwing out 15volts plus, changed condensor again, plugs, distributor cap, leads, serviced carb.
Its fine when its cold as soon as it gets hot (or at least runs for 20+ mins) it sounds like a bag of bolts, back firing and no acceleration!
Really running out of ideas now, anyone any similar experiences?

Denis

.
Very easy to overlook but if you've checked distributor lobes etc as the other guys have said, try looking at the carb base flange which may be distorting when it gets hot and also the bakolite spacer between carb and head for hairline cracks which expand when hot. Also check carb base gaskets. This spacer block used to be a favourite cause of hot running problems years ago.