Technical Fuel pump 1.1

[Ralf S.]

I inherited a Punto Mk1 (1.1 SX in 1994 flavour) that doesn't start... It's hardly a surprise since it's travelled about 150 miles in the last 6 years and zero in the last two. Otherwise it was running when it was last used... I mean it wasn't broken down.

Anyways, I put a battery from an aircraft carrier in it and it cranks well but nothing else happens.

It tries to catch on aerosol "Easy Start" and the plugs have a spark.. so that bodes well but I don't get a strong smell of petrol from the injector area so I think the problem is the fuel pump.

When I turn on the ignition, I can't hear a "whine" and when I crank the engine, I only get the faintest little dribble from the pump "out" pipe (on the pump itself). New pump is on order...

However, to be sure I'm not barking up the wrong tree.. can anyone confirm how to check that the fuel cut-off switch isn't preventing the fuel pump from working? The switch is "On" (pressed in) so it looks okay but the connector on the fuel pump has 4 wires and I don't know how to test that there is a current there. Two wires are black, one looks beige, the other more yellow/orange.

I'd like to be sure the plug is "live".

There are no lights on the dash. The dash lights up as normal and then they all go out, including one that looks like an injector, apart from handbrake and charge/oil pressure, so that looks good to go.

Ta,


Ralf S.

 

[bugsymike]

I inherited a Punto Mk1 (1.1 SX in 1994 flavour) that doesn't start... It's hardly a surprise since it's travelled about 150 miles in the last 6 years and zero in the last two. Otherwise it was running when it was last used... I mean it wasn't broken down.

Anyways, I put a battery from an aircraft carrier in it and it cranks well but nothing else happens.

It tries to catch on aerosol "Easy Start" and the plugs have a spark.. so that bodes well but I don't get a strong smell of petrol from the injector area so I think the problem is the fuel pump.

When I turn on the ignition, I can't hear a "whine" and when I crank the engine, I only get the faintest little dribble from the pump "out" pipe (on the pump itself). New pump is on order...

However, to be sure I'm not barking up the wrong tree.. can anyone confirm how to check that the fuel cut-off switch isn't preventing the fuel pump from working? The switch is "On" (pressed in) so it looks okay but the connector on the fuel pump has 4 wires and I don't know how to test that there is a current there. Two wires are black, one looks beige, the other more yellow/orange.

I'd like to be sure the plug is "live".

There are no lights on the dash. The dash lights up as normal and then they all go out, including one that looks like an injector, apart from handbrake and charge/oil pressure, so that looks good to go.

Ta,


Ralf S.

I had a Fiat Grande Punto that had no fuel pump actuation in the tank, bridged the fuel pump relay in the fuse box in the engine compartment and got it running, however in my case the problem was the trigger wire for the relay coming from the ECU under the bonnet had rotted through a few mm from the ECU inside it's plastic sheathing, it was only on pulling the wire that it appeared to stretch.

 

[GrandePunto PL]

Come on, this is simple fuel/injection system and electrical circuit.
Use wiring diagrams: https://www.fiatforum.com/threads/punto-mk1-wiring-diagrams-96-98.492983/
Check the Guide (nothing to write home about): https://www.fiatforum.com/guides/fuel-pump-assembly-replacement-punto-1-1-spi.868/
Should be easy to find what's wrong (pump, filter, hoses, injector, relay, fuse, switch etc.).

 

[Ralf S.]

I was going to make a test lamp with the male half of a Superseal connector but it got too complicated (I ordered a 4-pin connector but the fuel pump has a 5-pin... I blame the petrol fumes... )

While I was about to order a new Connector I saw a cheap pump (Marelli, brand new) so I bought that instead.

Connected it to the car and with the ignition on, it immediately started making a noise, which the old (32 years old, to be fair) pump never did.

I primed it a few times and the car started first turn of the key. Nice one!

Next job is the rear brakes.. the lining has detached from one of the shoes, so it'll be new shoes, springs.. and then while I'm there, probably new cylinders, wheel bearings and drums. It's getting expensive for a free car... but I'm guessing I'll do them once so I'll never have to do them ever again.


Ralf S.

 

[burakbc]

1,3 multijet 2008 linea euro 4 My vehicle has a leak in the component located under the fuel pump, specifically at the back side where the plastic connector is. Is it possible to repair this part?

 

[bugsymike]

1,3 multijet 2008 linea euro 4 My vehicle has a leak in the component located under the fuel pump, specifically at the back side where the plastic connector is. Is it possible to repair this part?

I think you are referring to the fuel pressure regulator, there is an O ring if leaking at that point , but otherwise it is normal to replace it complete.
When trying to locate a leak in that area remember it is extremely high pressure ( sometimes 28,000psi) and what may seem like a fine mist will actually go through your skin requiring hospital treatment.

 

[Ralf S.]

1,3 multijet 2008 linea euro 4 My vehicle has a leak in the component located under the fuel pump, specifically at the back side where the plastic connector is. Is it possible to repair this part?

Don't mess about. If it leaks after you attempted to repair it, the car is going to have a Viking burial, hopefully not with anyone inside it.

If there's any doubt.. just buy a new one.


Ralf S.

 

[There all puntos]

Don't mess about. If it leaks after you attempted to repair it, the car is going to have a Viking burial, hopefully not with anyone inside it.

If there's any doubt.. just buy a new one.


Ralf S.

Yea dude, my MK1 60s it's pump was fine, but in 2012 I took it for it's last ever legal mot (sold the Punto in April 2021 with a free 6 month DVLA MOT).

Now well back to its last MOT, the tester starts the Punto, gets his assistant to press pedals, operate electrics etc, etc.

But about 15 minutes or so the tester is at the back wheels spinning them by hand, the engine is still running so he migrates to checking the fuel pipe and brake lines

and low and behold the fuel filter explodes all over him, the engine dies.

He calmly removes his inspection goggles, turns around and gives me a thumbs down signal.

He asks me 'do you have a fuel filter handy?' (so he could continue) to mot the Fiat

I did, so he takes the old one off, fits the new, one charged me a extra £10 continued the MOT.

Asked me not to let him have a fag as his coveralls were soaked in unleaded fuel.

I had my suspicions that the line was leaking, as I smelt fuel when I did my pre MOT checks.

I had bought a service kit and a fuel filter, since the fuel filter hadn't been changed in over six years.

The tester put it back into its little white and gray box (he shook it) the old filter sounded like a maracà.