I usually take my 1970 Fiat 500L for a drive once a week just to get all the parts moving and inspect for leaks etc, and all has been great up until now. However, I haven't had the chance to drive her for 3 weeks due to work commitments, crappy winter weather etc and now I can't get her to start.

So the situation is, the battery and starter motor is working but the car just doesn't want to turnover. It usually works after about the 2nd or 3rd attempt.

I tried tapping on the carby with a wrench (a new Weber 126) and playing around with the screws, but nothing. One thing I have noticed is that the plastic fuel filter reservoir is completely empty. There is also none of the usual strong fuel smell in the engine area, despite having the choke open and pumping on the accelerator many times to try and get the car to start. I opened up the fuel tank lid and looked inside and there is a little bit of petrol left in there, but levels are quite low (less than a fifth of a tank).

I looked around the engine bay and on the ground and there is no evidence of leaks.

Any ideas? Thanks in advance.

Hi,
Sounds like failed fuel pump. The standrd pump is mechanical and mounted on the engine (follw the fuel hose). One check is to rig a temporary fuel tank mounted above the engine and connected directly to the carb. Gravity feed does not need a pump. However, be very carefull if attempting this, it's all too eay to drop the ank or spill fuel resulting in a burnt out car or worse.
The pump may have been weak for a long time and now the low fuel level was too much for it.
Search the Fiat Forum for pump replacement info.

Robert G8RPI.

Thanks Robert. Sounds plausible. I'll look into it.

Hi Sophia; One comment that you made which people seem to have missed is that you say that the engine doesn't want to turn over---is it not cranking at all? If it isn't, that is what you need to sort out first. Pumping the throttle on a 500 carb will achieve nothing--it has no accelerator pump. it might be worthwhile draining the fuel (at the fuel pump end) and then refilling the tank with FRESH petrol. Modern fuel goes off much quicker than the old 'leaded' fuel. As much as I hate using the stuff, have you tried starting the engine (as long as it cranks over) by removing the tube between the carb and the air filter and then giving a good squirt of 'easy-start' into the carburettor? This will tell you if it is a fuel or a n electrical problem. If it starts when using easy-start, with fresh fuel in the tank, then it is a matter of fuel supply, which may well be the tank. Sort out the basics first!

Hi 'the hobbler,

Thanks for your advice.

I should've clarified. The engine does crank and I'm pumping the accelerator pedal while cranking the engine (i'm assuming this is correct procedure?). I think the first thing i'll do is put a few litres of fresh petrol in. If that doesn't work then i'll move onto step 2 and disconnect the air filter hose and spray some of that 'easy start' into the carby.

Come to think of it, when I purchased the car the air filter hose was missing, therefore I'm guessing the previous owner had to do a similar procedure to get it started.

Sophia500 said:

Hi 'the hobbler,

Thanks for your advice.

I should've clarified. The engine does crank and I'm pumping the accelerator pedal while cranking the engine (i'm assuming this is correct procedure?). I think the first thing i'll do is put a few litres of fresh petrol in. If that doesn't work then i'll move onto step 2 and disconnect the air filter hose and spray some of that 'easy start' into the carby.

Come to think of it, when I purchased the car the air filter hose was missing, therefore I'm guessing the previous owner had to do a similar procedure to get it started.

Click to expand...

If it is a possible long standing issue there are other things to consider:
1/Blocked fuel pickup in tank
2/Failed fuel hose, non-fuel rated (or old hose with modern fuel) can swell internally choking off the fuel or fuel rated hose may have a thin liner that can detach and collapse under suction.
3/Wrong spacer under fuel pump mounting. There are different thickness spacers, if it's too thick the pump stroke will be too small.


I still fink failed pump is most likely.


Robert G8RPI.

Hi everyone,

First of all I would like to thank all of you for your help. As a 500 classic owner for six months now Its a nice feeling to know there is a wide community of like minded enthusiasts willing to impart knowledge.

Quick update for you all. I bought a 5 litre jerry can and filled it with some 98 octane petrol and gave Sophia a drink. Lifted the choke and cracked the engine a few times with the same issue. However, upon opening the engine lid I noticed the plastic fuel filter reservoir slowly but surely filling up with petrol. When it was about half filled I cracked the engine and Sophia came to life! It sure was a great feeling! So it looks like I've still got an issue to sort out with the fuel pump as it doesn't like the fuel levels being below about a quarter of a tank.

Anyway, so I decided what better way to spend the remainder of the Queens birthday long weekend then go for an evening cruise.

Cheers

Well done Sophia.
Enjoy your evening outing.
Jack

I had a similar issue the other week and followed all the logical steps to try and isolate why fuel was not getting through. I thought it was the fuel pump too as nothing was getting to the carb but before condemning it looked again at the Haynes manual. They said to also test that fuel was getting to the fuel pump by removing the inlet pipe from the filter - if the car is on a slope gravity should allow fuel to flow from the tank; if the car is on the level (which mine was) they suggest blowing back down the pipe until you hear bubbles in the tank - this worked a treat (having cleaned the end of the pipe carefully first!) and having put the pipe back again the car started brilliantly . Clearly it was just a case of some crud blocking the pipe somewhere (obviously a risk of it happening again but at least the cure was quite easy and clearly something to do very carefully to avoid a mouthful of petrol ).

There is a filter in the sender / fuel take off - in the fuel tank

Hi,
Some pick-ups have a wire mesh "sock" filter on the end, but not all. Some less well made ones have plastic or ubber tube on the end (so they don't have to be precise). This can drop off stopping pick-up at low levels.

Robert G8RPI.

Hi all,

Over a year later and another fuel system issue has now come back to haunt Sophia. This time I have filled up the tank to close to full, yet the little fuel filter reservoir remains completely empty when I try repeatedly to start the engine.

I'd appreciate any troubleshooting advice.

Thanks

I have found from experience that if you leave the 500 for a period of time (3 to 4 weeks on some occasions), somehow the fuel siphons from the carb and fuel-pump back to the tank. I have found that the only way round this is to pressurise the tank and thereby force fuel through to the pump. My method is to to use an electric tyre-pump. I take the hose from the pump and put it into the filler in the tank, holding it in place with rags (to seal it). Turn the pump on and put some air pressure into the tank. You will only have to run the pump for about 20-30 seconds. Remove the pump (be careful, there will be a slight expelling of the built up pressure), refit the filler cap on the tank and then try to start the engine. I don't know why this happens, but it has done it to me on a number of occasions--hence the reason I have the cure so sorted!

Thanks ‘The Hobbler’. I have an electric tyre pump, so I’ll give it a try tomorrow and report back.

Quick update. I was able to get Sophia started without doing anything different. My guess is that overnight some pressure built up in the tank. I will be taking her in soon for some maintenance and will get the fuel system looked at, but all is good for now.

Not wishing to be picky...but, you had the problem in June 2016 and a similar issue now.

What maintenance has been done between times?

D

Hi rallycinq,
No maintenance has been done between the two incidents. I need to get my arse into gear and get a few things looked at.

Sophia500 said:

Hi rallycinq,
No maintenance has been done between the two incidents. I need to get my arse into gear and get a few things looked at.

Click to expand...

Inactivity for these wee cars is not good for them, and the fuel systems fitted don't like modern fuels.

Enjoy the maintenance.

D