Fuel pump alternatives and diagnosis

[cjheath]

My Giulia 1300 TI stopped suddenly on the way home last night, and I rolled to a servo, did some checks and went home for tools. The mechanical fuel pump is not delivering fuel. I had a spare pump (the sealed type, not the original one) on a 1750 engine at home, and though it hasn't been used for 15 years, it was good and near-new at the time. I also took down a fuel bottle and some tubing, and fitted it up, filling all the pipes etc with fuel before attaching the (newish silicone?) fuel hoses. The fuel filter has been replaced with an empty canister, so that's not blocked.

No start. Prime the carbies, off like a rocket, 30 seconds later, it stops again - no fuel delivery from the pump. Can I be this unlucky? I took it all off again, blew air through the pump, and refitted it again, and it runs for a bit after priming, then stops.

I don't know if there's still a fuel pump problem or if a fuel line has gotten blocked. Or is there some other possible problem? The car had been running fine but stopped so suddenly... Both pumps have the little rocker that engages the pin protruding from the engine block, but I really don't know how to test if they're ok.

I need to get the car going again ASAP, or at least home, for a couple of reasons. My options seem to be:

• Buy another 105 pump and hope that fixes it
• Find an electric fuel pump, fit that and supply ignition power
• Tow it home and worry about it after my trip O/S

If I buy a new pump (either type), it won't fix any other problem there might be. How do you check fuel lines?

If I look for an electric pump, what do I need to ask for? I have a manual that specifies the required pressures and flow rates required. There is no pressure regulator so an electric pump will need to have that included.

Bear in mind, the car is 2km from home at a place it can't stay long, where it's not that easy to work on.

Any ideas are welcome!

[Colin Byrne]

That's no good

Sounds like a blockage in the fuel line, Maybe pull the tank pick up out and check that.

Are you absolutely sure it is fuel, how are you determining that the pump is not delivering fuel? Have you pulled the top of a carbie and checked if the fuel bowl is full or empty? Could be electrical, particularly if it's dying very suddenly

Compressed air is not a bad way to clear lines, bit hard to do on the side of the road though

If you by an electric pump you need a low pressure one (3 to 5 psi), if you do this you can put a regulator in but you don't need one.  Also a good idea to put a tachometric relay or connect through an oil pressure switch so the pump only runs with the engine turning over.  The only way you can use a high pressure fuel injector pump is If you put in a return line and a fuel pressure regulator.

Let us know how you go

[cjheath]

Thanks Colin - you're sleepless too! I did some googling and it seems there can be a problem with the drive pin that engages the pump's rocker - it might be the wrong length for the 1750 pump. Although both engines have the pump angled back at 45 degrees, unlike in some other version of the engines, so you'd think they'd be the same. That doesn't explain the sudden failure either, but perhaps the original has a dodgey valve. I was climbing a hill at the time so the fuel tank was below the engine...

Hooking up a Facet FED-40105 to the oil pressure switch sounds like the best option, except it likes to be beside the tank, and that means cutting into lines and fitting hoses, etc, hard where it is. Maybe jerry-rig it to get the car home and mount it properly afterwards. There seems to be a choice of places near here to buy them.

[cjheath]

It all looks different in daylight than by the side of the road at night. The drive pin was fine, not jammed or broken or anything (apparently the distributor drive shaft can break if the oil pump is installed wrongly!).

I'd connected the input and output hoses to the wrong ports on the (Alfetta-style) fuel pump

All is well now, except I need slightly longer hoses to reach the different port locations.