Fiat Dino Forum (FDF)

Hi All.

I'm just about to refit my carbs after a rebuild and this has prompted me to look at the fuel system as a whole.

It's been suggested that late Coupes (I believe mine is one of the last) have a fuel filter assembly mounted onto the left inner wing. See the diagram attached.
Mine, however, doesn't. I have hard fuel lines arriving at the engine bay from underneath, that rise up the bulkhead, near to the brake fluid reservoirs, and then turn towards the passenger side and travel along the bulkhead below the windscreen. They terminate there, where they connect to the fuel hose for the carbs (both supply and return). So no fuel filter in the engine bay on mine. it looks very stock and original. My hard lines stop, more or less at the centre of the car, in line with the carbs.

Is it possible that really late coupes did away with the combined fuel filter/regulator as you see in the diagram?

At the rear of the car, and next to the fuel pump I have an inline canister filter fitted. But no regulator - so maybe my fuel pump doesn't need one.

Does anybody else have this setup?

I've seen some cars with a Filter King fitted on the inside of the LH wing/fender where you see the filter/regulator on the attached diagram. Is that to replace a no longer available stock regulator?

To my knowledge:
2400 Coupes do not have a pressure regulator. 2000 Engines have. So your Setup in the engine bay seems to be quite original. As the 2400 have a fuel return line a regulator is not as much needed as in the 2000 without a return line - although many 2400 owners have fitted a Filter King later - as I also did. By the way: The original units are not specifically very rare.

Thank you, Thomas for the response.

Why did you add the Filter King? Did you need to regulate the fuel pressure down from a non-standard fuel pump that would otherwise overwhelm the carburettors? Or simply to provide a secondary filter?

I wonder if we should look at fuel pressure. Check our fuel pump, maybe.

3 of us today have walked away totally confused as the car will still not start, despite the rebuilt carburettors. They've been totally stripped, cleaned, blown through and fitted with new O-rings and gaskets. The float levels have been set and new needle valves and accelerator pump diaphragms fitted too. We've tried idle jets ranging from 0,50 to 0,60. There are no air leaks. We've started from a base point of having the idle jets turned out 2 turns and throttle stops turned in one turn.

The fuel pump is working and we're getting fuel into the carbs.

The starter is turning and we have more than 13v at the coil. We're getting a good strong spark at each HT lead and spark plug. Compression is between 11.5 and 11.75. Spark plugs are good. New, clean 98 RON fuel.

The engine very nearly starts and on a couple of occasions, it has started momentarily. When that happened we pulled on the hand accelerator and the engine immediately died. We've tried starting with the chokes fully closed, fully open and anywhere in between. The Idle jet screws have been turned in and out from anything from 1 turn out, to 3.5 turns out.

Spraying carburettor cleaner, or pouring fuel into the chokes seems to produce some positive results and suggests that the carburettors aren't getting enough fuel.

We spent a whole day with the car and and finally we walked away totally despondent. Rebuilding the carburettors seems to have had no effect.

I'll try again tomorrow and maybe take the tops off the carbs to see how much fuel we have in the float chambers.