Fuel starvation?

[Jonny8]

1962 Cooper S with electrical SU fuel pump.

Took the car out for a run, it was hesitant at times which got worse until I had to get a tow home

Looking at the fuel filter, it was empty. So I suspected the fuel pump.

Electrical connections all look solid. When I turn the ignition on, I get an occasional jerk from the pump (it’s out of the bracket) and a tick.

Taking off the fuel filter, there was gas/petrol in the line on the other side.

What’s the simplest way of testing the fuel pump? Happy for other suggestions of what might be up.

Had the car 12 months, so it’s still “new” to me!

Thanks in advance.

[Jonny8]

Oh. I was going uphill when it finally gave up!

[Fanfaniracing]

For me the easiest way would be to take of the fuel hose before the Carburetor. Turn the ignition on and there should come fuel.

If you're allready taken of the Pump, connect it to a Battery, the inlet in a Canister of fuel, tve outlet to a cup or something.
This way you can control if it works and how much it feeds per minute...

[Peter Laidler]

You haven't given us a lot to go on but from the sound of it, it seems that your fuel pump might be clogged up. We don't know what side of the pump your filter is either.

What is the flow like to the fuel bowls? What pump have you got? The standard SU? See what I mean about lack of info

You could take the intake and outlet covers off and rinse the internal filters out out for a start. Or, as happened to me, check that the fuel bowls are clear of the little bits of clag and crap that finds its way into them, blocking the path to the hose that feeds the fuel to the jets by gravity.

[Jonny8]

Some more details…. Fuel filter is between the pump and the carbs.

With the ignition on I get an occasional tick from the pump, but don’t see the fuel filter fill up.

Fuel pump is still attached, so I can try taking the hose off the carb end and see if there is flow.

Pump is the standard AUF201 electrical pump.

Thanks for some things to try further the diagnosis!

I’ll mess around tomorrow AM and report back!

Thanks again

[Polarsilver]

Check 12v Supply to the Pump & a good earth .. then I go for reliability over originality so fit the none standard German "Blue" Fuel Pump from the likes of MS cost circa £90 ( i paid about £70 so the price has gone up ) also fit a pre filter ..i fit the pump with the earth adjacent to the Pump ..never had a Pump issue since .. change the flex fuel lines ( yes tank(s) comes out) as even if they are up to the task of todays fuel i find these modern pipes go hard over time & have potential to split.
just saying with lots of experiences that todays so called Petrol can go off in just a few weeks.

[Peter Laidler]

I only ever even slightly disagree with Norman with a great deal of trepidation and thought but...... While I agree that modern fuels can hsrden and rot the standard fuel hoses, FROM THE INSIDE OUT so remain undetected until they split. It;s happened to me. I don't believe that modern fuels deteriorate at a greater rate than the old stuff. My 2001 year Rover Cooper has been laid up for almost 2 years on mmany occasions - Covid and being left in Germany being good examples - and much to my surprise has started on the first or second click of the key. More than can be said of the radio that has been as dead as a dodo for the past 5 years!

My lawnmower sits in the open, under a garage overhang nloved and unused for 6 months and also fires up first time.

A blockage - also happened to me - is the likely cause

[MiNiKiN]

1962 Cooper S with electrical SU fuel pump.

Took the car out for a run, it was hesitant at times which got worse until I had to get a tow home

Looking at the fuel filter, it was empty. So I suspected the fuel pump.

Electrical connections all look solid. When I turn the ignition on, I get an occasional jerk from the pump (it’s out of the bracket) and a tick.

Taking off the fuel filter, there was gas/petrol in the line on the other side.

What’s the simplest way of testing the fuel pump? Happy for other suggestions of what might be up.

Had the car 12 months, so it’s still “new” to me!

Thanks in advance.

Also check there has not been any tank sealer applied previously, that has come undone and blocks the fuel line now.

[twc641]

With the fuel pump removed see if any debris comes out of the inlets side, I would also fit a clear filter between the tank and the pump this will not only protect the pump it will verify rust , water, and peeling tank sealer before it gets to the pump.
As Peter has stated i also doubt it is the hoses.
John

[gs.davies]

The most common cause is the points inside the fuel pump being out of adjustment/dirty/worn.

My last pump ran for several thousand miles before starting to intermittently be a bothersome little

I cleaned the points up and adjusted twice before giving in and fitting a hardi pump.

Standard issue fix for this is to fit a facet - they can be noisier though, but they’re readily available and therefore easy to repair at the side of the road.

[Exminiman]

Agree with all the above, problem may be caused by old rubber flex fuel pipes breaking down with new E10 fuel…..rememdy is to clear out the fuel system and replace tye pipes with e10 resistant ones….

[111Robin]

Until you confirm 100% that the pump is delivering and delivering sufficiently there is little point messing around with anything else. Take the pump off, hook it up to a battery and try to pump fuel from a container and measure how much you get in a minute then check with the recommended delivery rate in the manuals.

[1071bob]

Its worth checking the flow rate and reliability of the pump, after I fitted the fuel tank and rebuilt SU pump and new pipework I used a length of flexible pipe from the feed pipe to the carbs back to the fuel tank filler. I ran the pump for two hours occasionally 'crimping' the pipe to simulate the float chamber valves closing. The pump flowed one litre of fuel per minute.

[WZD345]

If upgrading the fuel pipe, best product to get is Mocal SAE J30 R9. Switched over this as I was experiencing pipe degradation on older pipes due to fuels. It's a bit pricey, but the best.

[111Robin]

Delivery rate should be just over 0.5 litres per minute