I'm having a big trouble with my Alfa Romeo 33 1.3v Twin-Carburetor.
At the current state the engine starts fine and goes very well in the beginning, but going uphill after a while she starts to misfire and backfire at the same time, she loses a lot of power. I can't say how many cylinders are running when this happens, what i can say is a lot of backfire, noise and she shakes violently.
The car have always used both 95 and 98 octane fuel and stud still for a year, after this run 1000 km having some trouble starting the engine and when i had to stop the car the engine turned off several times. After some km's done this two problems happen less frequently and until now she worked without any problems.
What i done so far:
- tested for O2 and perfect result, no emissions
- changed spark plugs
- changed fuel pumps
- changed electronic distributor
- changed coil
- cleaned and tune both carburetors.
Still to do:
- compression test
- change spark plugs wires
- change fuel filter
Still to do based on your responses:
- Pressure test in the fuel system behind the pumps
- Empty, blow with air and clean the gas tank
- Check voltage going into the fuel pumps at high engine load
I have also to report that yesterday i tried to refuel the car after testing it, and with the tank empty she started to spill fuel after putting 1 liter of fuel inside. I was perplexed with this occurrence and started to think the problem relays inside the fuel tank instead of the engine.
Thanks in advance for all of your help.