Fiat Dino Forum (FDF)

Hi all, I wonder if anyone can give input as regard my 1967 2.0 syder. I am still awaiting collection though paid for. I have been on test drive and was impressed.However one small problem(i hope) on starting up the dealer stated the following.It is common to have starting problems so to mininmise.Switch on (dont turn over)repeat await to hear fuel coming through then you can start up.I would add this was succesfull however they suggested fitting a bypass to alleviate this problem.I am awaiting the outcome of this.

Congratulations to your Dino ownership! Concerning your question about starting problems; In original, the Dinos have a engine oil pressure sender, situated at engine´s right side (together with the ordinary oil pressure gauge sending unit) - wired to the special fuel pump electrical relay. This is an safety item - if oil
pressure is too low, the sender activates the fuel pump relay to CUT OFF power to the fuel pump.

In other words - if you are trying to start the engine, having not been running for some days, you are likely to be cranking the engine at the starter for some seconds
to get some oil pressure - which means the fuel pump can start delivering fuel to the carburettors. This means, you will never be able to activate the fuel pump just
by turning the ignition on - if you don´t already have some oil pressure in the engine!!

In practical use - this is not a major problem, if driving your Dino now and then. You will have enough fuel in the carburettors left, to be able to start the engine at
once - and after starting, the engine hopefully will get oil pressure in the system - which will stop the obove mentioned safety system to cut off the fuel pump.

My personal experience is: if my Dino is not driven for - say 14 days - I will have lost most fuel in the carburettors, and will have to crank the engine, as described
above. My guess is, the fuel in the carbs simply evaporates by time. I have solved this problem through installing an extra microswitch, delivering power directly
to the fuel pump.
Finally - it is not impossible, some earlier owner of your Dino has cut off this original safety wiring, to get an easy starting procedure. If so, you have to choose if
you want the safety arrangement back - or not. If you asked me - I would strongly recommend to make sure, this safety item works as designed - otherwise you can
end up with an wrecked engine, any time you don´t expect that to happen....posting.php?mode=edit&f=7&p=926# Hoping this
helped you in some way!! / Dinoswede

As far as I know, the ignition switch will override this safety feature since there is never an oil pressure when the engine is stopped. That's why you hear the fuel pump when you turn on ignition.
As already mentioned in another thread, the Dino starts very well if everything is OK and there is no need for any starting aid or workaround. Mine starts after 3-4 seconds cranking even after a 4 month winter break.

Tobi; I was surprised reading you comment that the ignition switch overrides the oil pressure safety switch - I have now checked my 2 litre Spider electrical diagram
to see how the wiring is done. As far as I can see, the ignition switch has a separate wire (blue/black) running from the ignition switch (no 16) to the fuel pump
relay, as you wrote. BUT - it gets powered only in the starting position, not in the ignition position. PLease note - it is not the starter solenoid wire (no 50/red) - it
is a separate wiring, from no 16 at the ignition switch. So, you must crank the engine, to get the fuel pump working! That means we can forget all about the oil
pressure switch - during the starting procedure - it has no influence during the cranking/starting sequence, at all. As soon as the engine runs, the oil pressure safety
system takes over the power supply to the fuel pump, as I understand it.
All this apply to the 2 litre cars, obviously - are the 2.4 Dinos wired different? I suspect so. The original wiring diagram for the 2,4 cars are showing the same
wiring from ignition switch (no 16) but now going DIRECTLY to the fuel pump, so I guess it is fair to say Fiat did some kind of upgrading here... Ciao / Dinoswede

Dinoswede, you're right about the relay. It comes into play with running engine only. With stopped engine, the pump will be supplied with power by the ignition switch, but already when ignition is on, not only during cranking. I can definitely hear it on my 2400. And I've never heard about a difference for the 2000s. The 2000 wiring diagram that I have shows no difference also. Maybe there was a change from series 1 to series 2 already?

Hi again, Tobi. My 2 litre Spider is from the second series, but I can assure you, the fuel pump in my car is never activated just by turning the ignition on. Before
I installed my "by-passing switch", I had to crank the engine for quite a while until starting, if not driven for longer periods. Notable is, if the car is driven - say
2 days ago - it will start directly. I therefore have guessed, the fuel slowly evaporates from the carburettors by time.
I got the idea with the "by-passing switch" when turning the ignition off with engine running. and - as soon as the engine had stopped, turn the ignition on, again.
Then I could clearly hear the fuel pump running for a few seconds - then it was cut off by the dropping oil pressure, activating the oil pressure safety relay, of
course.
My guess is, Fiat noticed some owners complaining about this starting problem with the 2 litre Dinos, if not driven regularly, and just made the change in the
wiring. I have the owner´s manual for the 2 litre Spider (with the wiring diagram included). Interesting is, some of the photos are showing an early Spider with
an engine with DCN carburettors (no choke in the carburettors) and no Dinoplex under the bonnet - other photos are showing a late 2 litre Spider with the wooden
dash. The printing is dated December 1967, so I guess it was meant to go with "the second series" Dinos. / Dinoswede