Noisy Fuel Pump

[TRTerry]

I have also posted this in mechanical.

My pump makes a lot of ticking noises, especially at idle. Less an occasional tick, more like Ginger Baker on a drum solo. Then a pause then off it goes again.

The car works fine and is happy at all speeds. Fuel consumption seems OK, and no obvious leaks or petrol smells.

The unit is an old Mopar equivalent and has been on this car for at least 21 years.

Should I be concerned?

Thanks


Terry

[simmitc]

You could service it - clean/replace points, change diaphragm and valves; or just carry a spare in the boot - if you have it with you, you won't need it, but if you leave the spare at home, then your current one will fail! Beyond that, I wouldn't worry.

[TRTerry]

I am not sure if the Mopar pattern replacement is serviceable?

It does not have the correct union fittings for the fuel inlet, instead it uses a rubber hose and the previous owners have cut off the flared end to the copper fuel pipe.

[simmitc]

Now that IS annoying - you'd need a stub of fuel line to fit into a proper SU pump in order to connect the rubber tubing. The "proper" solution would be to renew the whole copper fuel line, but then you're into whether the union will unscrew from the tank... Under no circumstances should you try to solder a new connector to the existing pipe - petrol vapour and heat are not good bed-follows

[TRTerry]

I have copper brake pipe, is that the same size?

And I have a flaring tool.

But I don't have the union fitting, would you know what it's specification is?


Thanks


Terry

[bmcecosse]

'Copper' is not correct for brake pipes!! But in any case - too small for fuel line. I would first check/clean the internal filter if the pump has one - and have a look at the contacts. They may be sticking slightly - and then having to 'catch up' when they free off. And if there is a filter after the pump - between pump and carb - throw it away.

[TRTerry]

Well copper coloured, it is pukka brake pipe brought from a motor factors.

Yes you are right about the fuel pipe being bigger, that's down to my crappy powers of observation - thanks

I know a strip down holds for a SU pump, but am not familiar with the Mopar pattern part. It already has external differences.

I wonder if the diaphragm is punctured so that the pumping action is not totally effective. The car died slightly on me today for a few moments ( on the A46 dual carriageway). So I think fuel starvation. But the engine free revs satisfactorily. I also now believe I can hear pinking occasionally at any revs or load, symptomatic of fuel starvation?

What I normally do is replace as I have a pump, then see if the dodgy unit can be fixed as an emergency spare. It has been on at least 21 years after all. But I will have another look at it while trying to source these other parts.

Does anyone have a gash 6 inches of so of fuel pipe? and a union nut?


Thanks


Terry

[bmcecosse]

Post up a picture of this Mopar thing....... is it not just an SU badged up as Mopar?

[TRTerry]

Not my best shots, but you can see the right angled rubber piped connection. It looks all integrated to me.



[frame][/frame][frame][/frame]

[bmcecosse]

Looks quite like the Mini SU pump - which is a 'pusher' rather than a 'sucker'. This explains why it struggles to suck the fuel up from the tank. But it's managed for 21 years now - so fingers crossed for another 21 ........

[MarkyB]

The actual pump end looks like that on the electronic pump I swapped in favour of a genuine SU item because it was so noisy.
The sound from the electro-mechanical SU is still audible but much less harsh.

[Declan_Burns]

Just mount it on two anti-vibraton mounts and that will quieten it.
Regards
Declan[frame][/frame]

[MarkyB]

Doesn't the pump body need to be earthed?
Maybe one of the Black wires in the picture?

[bmcecosse]

It will earth through the fuel pipe - perhaps not the best idea, so yes a good earth wire would be wise. But this arrangement could over time fracture the fuel pipe due to vibration from the pump jiggling about on the rubber mounts........

[Declan_Burns]

I have a separate earth. There has been no problem with the fuel pipe fracturing and it has been on for over 5 years. It makes a hell of a difference to the noise level but you can still hear the pump ticking but no droning.
Regards
Declan

[daveyl]

Interesting. I have one of those 'mini' pumps on mine (as pictured), curious as it's made in New Zealand. It has worked well for several years. Famous last words, perhaps.

[TRTerry]

I finally sourced a replacement pump, and a new union nut as mine was missing, and some rubber fuel pipe. Took off the offending pump only to find a split in the inlet pipe hidden from view, AND that I could replace it with new rubber fuel pipe!

Did so and the pump is as quite as a mouse now. It just sounds a beat or two on ignition, and then can be barely heard while driving. It had been noisy for years so I guess the split has been there for a long long time.

Anyway at least I have a usable spare in the boot now.

Thanks for all of your help and suggestions.



Terry

[MarkyB]

Sounds perfect, you want to know it's working but it shouldn't be intrusive.

[bmcecosse]

You should fit the 'spare' to see if it's working. You know the one you remove is working - so it's the best spare.