Technical Stuttering at idle

[BarryH]

Hi all,

Setting the scene a little, working through servicing parts etc atm. Bought a carb service kit for 26IMB10 and all parts cleaned. New plugs and leads. New fuel sender, powerspark ignition installed and thermal lagged distibutor hopefully as a further heat guard. The one thing i have noticed is there is an ocasional stutter at tickover and noticed a lot of bubbles in the fuel line. Can I ask if anyone knows would this fuel pump be an orginal non serviceable part so looks like a one piece so cannot check for leaks and blockages etc and also where the copper fuel line enters the engine bay there is no hose clip at the join to flexible pipe so wondered if others have the same setup as thinking it may be drawing air in at this point and should have a hose clip

Many thanks

Barry

 

[Goldnrust]

Bubbles in the fuel line is often caused by small leaks in the lines or in the joins between hard and soft line. Yes, it would be wise ot have a hose clip on all joins. If this is the cause of the bubbles, I don't think it's causing your idle problem.

Remember in a carb the fuel pours in like a tap in a bath, those air bubbles will come straight out of the vent and the fuel in the bowl will be bubble free. It's not like a sealed high pressure injection system where the bubbles would come through the injectors causing them to temporarily stop flowing fuel.

The exception to this, is if the bubbles are caused by the fuel boiling and the carb is vapour locking. Does the idle issue show up after the engine has got particularly hot? Or is it still there on cooler days when running the engine less vigorously?

 

[BarryH]

Hi, at this stage the Fiat hasnt been run in ernest on the road so only being warmed up in the garage but i would say once warmed up and the thermostat has opened the flap. I have noticed the plugs suggesting to richer mixture but tried a leaner turn on the mixture screw but no difference - hoping to get a colortune look see in the next few days to confirm mix