General FIXED: Car idles, but would stall, sputter when accelerating

[tminus3]

Hi Guys...

So I see a lot of issues here where we spend time diagnosing it and trying different things. I just wanted to post a fix for anybody experiencing this problem. This by no means is rocket-science or anything spectacular, just a fix that I wanted to share.

Problem: Car starts and idles perfectly, but as soon as you step on the gas, it sputters and stalls.

Solution: Turns out it was really dirty float bowl that clogged the emulsion chamber and eventually the main jet.

Details: Full tank of gas (ethanol ), new fuel pump, new fuel filter, original Weber 26IMB10 carb.

Car used to run fine and I have been driving it around town for a few months. Then one day car started just fine, idled perfectly. But as soon as you tried to accelerate, it stalled. Turns out the transition from the idle jet to the main jet was the issue. When I took the carb out and started to dig into it, everything was quite tarnished and dirty. But the real kicker was the float bowl. there was a small cache of dirt, dust, debris, gunk in the bottom of the bowl. I cleaned that out. Then took the main jet and other jets out from the top of the carb and blew them out. After a lot of consistent blowing into various orifices and making sure the air was flowing freely. Installed it and fired her up. Runs great!

 

[the hobbler]

Thank you for your input---it all helps. I was in the motor-trade for most of my working life, ended up building up a couple of M/Benz workshops from scratch. Even on these cars, it was surprising how many faults were cured, not by expensive electronic devices, but by applying simple 'bush mechanic' checks.
Due to the rate that most garages go through fuel these days, 'foul' fuel is nowhere near as common as it was when I started motoring, but it is still something to check for when the engine coughs and splutters.

 

[tminus3]

New symptom: Car was stalling after it warmed up and had been running for a while.
Fix: tightened the carb to the carb plate, there was some play. Once tightened, idle smoothed out and I was able to lower the idle and get it in the sweet spot.

 

[The Whitakers]

New symptom: Car was stalling after it warmed up and had been running for a while.
Fix: tightened the carb to the carb plate, there was some play. Once tightened, idle smoothed out and I was able to lower the idle and get it in the sweet spot.

Mine came loose once but unfortunately it sucked some of the gasket in through the manifold. Had to strip the carb fully of and fit new seals....

 

[fiat500]

Mine came loose once but unfortunately it sucked some of the gasket in through the manifold. Had to strip the carb fully of and fit new seals....

I suspect that a lot of peoples' erratic running problems are caused by things like that. Everyone immediately jumps to the conclusion that it's dirty petrol.
One of my two hiccups this year was due to a tiny fragment of PU sealant breaking off a temporary repair I had made to the plastic, 650 version of the air-cleaner lid. I've since replaced it with the crack-proof metal lid off the 500.