Technical New bambino

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Technical New bambino

Bambino55

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May 9, 2018
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Hi Guys
I just bought a new bambino after 16 years since my last one. NEW TO THIS FORUM.

I bought MY FIAT as advertised as a 69 Bambino with an Abarth motor. I am pretty sure it does not have an Abarth motor.
On the sump is the word ALQATI and near the rocker cover on the motor is stamped AK84M and under a large 650. It also is stamped ALQATI on the carb manifold.
Rego papers says eng no is 126A10007703191

Had problems getting home in it as frequent breakdown, backfiring and stops for 5-10 minutes before heading off. Found out if i maintained a steady speed it was fine but stopped as soon as i lifted off. Thankfully it was all Motorway.
Next morning,yesterday, I started it and noted in the fuel filter before the fuel pump the filter was full of airbubbles/fuel frothing. The fuel drains away from filter as soon as it stops. I repositioned the filter higher so that bubbles/air at top and fuel at bottom going into pump.
Started it and same problem, not willing to idle and backfiring.
Between fuel pump and carb is another tiny filter which has very little amount of fuel going in.
I took the dizzy and cleaned cleaned contacts on cap and rotor contacts - started it and still same backfiring and no willingness to idle.
Put in a spare old HT lead to plug and took off plug to front cylinder and cleaned. Put plug back started it and same problem.
I have ordered a new fuel pump.
I will buy new HT leads and plugs
I will check points.
Is there anything else I can do. How can I fix the air bubbles in fuel? The tank is full of fuel.

1. Is there anything ABARTH abut this Fiat?
2. How do I get it to idle and run without the backfiring?
THANKS ALL
 
Hello and congrats on the purchase.


I'm sure the more knowledgeable members will be here soon to help you, but in the mean time, I would suggest cleaning the jet's in the carburettor. I had an issue with the engine stalling when lifting off, and it seemed to do the trick.


Change fuel filter as this also could be clogged up. Check the fuel filter inside the carb as well as there might be more debris. Eventually you could run without the filter temporarily, to see if the filter is causing any issues.


Post some pics.
 
Backfiring is caused by a timing issue. Check timing. Also do your valve clearances. Theres a link to a haynes manual in the stickies section
 
All the advice so far given is sensible, but I would like to add my "a'pence worth". As well as checking the fuel filters in the pump and the carb, don't forget the strainer/filter on the tank unit. (check also for muck in the tank). As well as cleaning the carb's jets, give all the passage-ways a good blow-out. also, check that all the mating surfaces are FLAT--it is not unknown (in fact quite common!) for the carb flange as well as the Bakelite spacer to be warped. Use a sheet fine wet-'n-dry (wet) on a sheet of fairly thick glass to ensure a really flat surface. When the carb is out, check that the float has no fuel in it (if it has, it will 'rattle' when shaken--RENEW), that the needle-valve is not ridged and that the float level is correct.
As you have 'points' ignition, you can check the timing statically (with a test light)--10 Deg BTDC/14mm. All these items are basic set-up/tuning; check them and get them correct before spending money on possibly unrequired parts. It is quite common to have bubbles in the in-line fuel filter.
ALQATI are a well known and respected tuner in Italy (they make some of the better exhausts), so don't worry on that score; but the seller should have his bum kicked for describing it as "Abarth"--naughty!
 
It’s quite common for the air filters to be frothing away and full of bubbles, sometimes they are full, half full, full of bubbles, so I wouldn’t take to much notice of that. I think if you had the chance to see the fuel filter whilst the car was moving you would find it full of fuel.

As Damian said check things like timing, valve clearance etc.... first to make sure they are all good.
 
Running issues aside my ears prick up when I read ALQUATI. Having said that like Tom says if you have two on line filters then you have one inside the tank, one in the fuel pump and one inside the carb. Then 5 filters on a short pipe run is excessive in my opinion and you could run a straight line from the pump to carb and if desired a glass filter on the tank side of the fuel pump. You did not mention what carb you had? With an ALQUATI manifold the carb is most likely a Weber 30DIC. The AK84M on the cylinder head shows that you have one of the last series 126 cylinder heads so the largest standard valve sizes. So the question is how "ALQUATI" is your engine? It could well be a rare piece of Fiat engine tuning that has found its way to Australia, much rarer than anything with an Abarth tag or it could be a tuned engine in an ALQUATI frock. The cylinder head is too late for an original conversion but what lies beneath?
 
Thanks guys for the replies.
I did not receive notification that anyone had replied so I did a google search on classic Fiat dealers near me.
With distances in Australia measured in light years I was fearing my ‘local’ classic Fiat dealer was going to be the equivalent of London to John.O’Groats.
I lucked out.
My dealer is just 15 minutes away working from a business in his home and rebuilds and races classic Fiats. YAY!
Bought some parts and today replaced Dizzy cap and leads, coil lead, condenser and started up. Still the same rough running and backfiring and inability to idle.

Next stop - points, timing and carb.
Ross from the Fiat Shop suggested retorquing the head bolts.

Started a new thread re Alquati bits just to gauge what I have. Excited at the prospect that i might have something special.
 
Sounds like you are only a couple of hours from me in Canberra

Ross at Fiatorque is great and for any work I could not do myself I have had done by him. In particular he machined the aluminium crank case and fitted a new Cam bearing for me.

The engine is still on my bench waiting for me to finish the car.

For pats they don’t have, Axel Gerstl and FDricambi web shops have been good to deal with.

A member of the Fiat club here had similar symptoms to yours and a carby rebuild kit sorted it out.

Cheers
Geoff
 
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