Technical Fuel pump dead. Gas cap or redex?

[EricKob]

hello forum people.

I have owned a 04 panda 1.2 for 8 days now.
On the 5th day, the car started to lose power, couldnt rev over 2k rpm.
Then the car idled ok for a while and died.
I tried banging the fuel tank from under the car with my hands but with no results.

Called the tow truck man who highly suspected a bad fuel pump.
Confirmed later that evening. when I gently hammer the petrol tank, the car would start then dies after a few seconds.

Now my question is why did the pump fail?

a-on the second day I owned the car, I added some redex (inj. cleaner) to the fuel to give the system a bit of a cleanup.

b-The car's gas cap was stuck and could not be closed properly = no seal.
I bought a simple 99cent replacement gas cap and put it on the morning of the breakdown = fuel tank sealed.
When the car broke down, my first instinct was to check the gas cap. when I removed it, there was a loud swoooosh/suction noise

Could either cause a fuel pump to fail? Or am I just unlucky?

I ordered a fuel pump but am now wondering what could cause this and should i put that gas cap back on?

 

[jackwhoo]

unlucky


you could fit a new fuel pump fuse in case current one is cracked, yes its unlikely but it is easy and cheap.

 

[EricKob]

i checked the fuse already

i m more worried/intrigued with that gas cap really

 

[jackwhoo]

If you have any doubt get a fuel cap designed for your model.


I cannot see the wrong cap causing failed fuel pump.


I have seen fuel tanks collapsed when then incorrect cap fitted but that was many years ago.

 

[jackwhoo]

It is far more likely your fuel tank is full of rubbish due to previous owner not having fuel cap.
Doesn't it rain frequently where you are?

 

[EricKob]

it does rain quite a bit yes

I m only wondering about the fuel cap because with it on, 15 miles later, the fuel pump failed... i d say i ll drill a tiny hole in it just to be on the safe side?...

 

[jackwhoo]

water in tank could cause premature pump failure.


It is unusual for any modern vehicle to have a vented cap due to emission regulations.


If your current cap is what can be called an emergency cap its worth getting a correct one for safeties sake.


Have a look on mickscarparts its Irish.

 

[irc]

I think a vented cap will cause EML to light up, as will not "clicking" the proper cap when fitting it.
Are you sure it was "sucking" and not "blowing" when you released the cap? (Stand by for some crude comments...)
I'm fairly sure there should be either be no pressure or a slight positive pressure when releasing the cap.
You may have a blockage.

 

[EricKob]

You re right. it was more of a blowing noise.

Are fuel tanks completely sealed (no air in, no air out) or do they have a venting mecanism, valve?

The cheap cap i got is just doing that job: sealing the 'hole'.

Ah, i think i m just overthinking this :bang:

 

[jackwhoo]

Honestly just buy a proper cap designed for the car.

There are a number of complicated emission control systems relating to the fuel system that can cause problems by the wrong or missing cap.

There is a system which allows air to enter the tank , so a vacuum is not formed on the tank which would collapse the tank under outside air pressure.

Just get a proper cap , honestly it's best all round.

If you don't get a proper cap now and later have problems you will kick yourself.

 

[EricKob]

I ll take your advice
Thanks mate

 

[jackwhoo]

No problem , thank you for listening.

 

[Chamonix]

Sorry to hear about your troubles. I've got a fuel cap on a scrap Panda you can have. PM me your address and I'll get it sent from the UK early next week (in France at the mo).

Incidentally I've used Redex injector cleaner a few times and it's made a big difference to performance, so I wouldn't worry about that having damaged anything.

 

[koalar]

Will run fine without a cap for testing


Shouldn't have much vacuum when releasing the cap


There can be positive pressure and release of air when undoing the cap.


Can you hear the lift pump whirring when you switch the ignition on


Have you got fuel in the car. Having just bought it don't rely on the gauge.


If the pump in the tank isn't switching on there was a common problem with the ECU pins corroding.


I the car has been standing before being sold there may be water in the air filter. Also a very common fault.
https://www.fiatforum.com/panda/152968-multijet-loss-power-after-cold-start.html

 

[DaveMcT]

Used pumps are not silly money

http://www.ebay.co.uk/itm/FIAT-PAND...e:Fiat&hash=item1c7d8f2e6f:g:hgIAAOSwfVpYrAgM

Yo can also but a new motor/pump unit for about £30. Basically all the same
http://www.ebay.co.uk/sch/i.html?_o...nk.TRS0&_nkw=12v+petrol+pump+in+tank&_sacat=0

I recently fitted one to the bike & works perfectly. Has to be better than £200 that BMW want for the whole tank mount and frame etc etc.

 

[EricKob]

New fuel pump received and fitted yesterday (130 with misterauto).
Good amount of crap in the bottom part of the pump so the car having no proper fuel cap for some time surely did the job...

I looked into used pumps but decided against it. I prefer peace of mind over economy

Car's up and running now and a proper fuel cap is on its way.

eace:

 

[DaveMcT]

My bike uses a car style fuel pump with the same type of large circular access cover. I fitted a new pump motor to the existing pump mounting. Cost was about £30 and I needed to add about 1/2 hour's work to swap out the old pump motor - on top of the time to access and open the fuel tank.

Anyone doing this job take great care when refitting the pump unit into it's sealing gasket. I used red rubber grease on the gasket inner face. If it sticks to the pump body it can come loose. However you will not know until you fill the tank and discover it leaks.

DAMHIK

 

[EricKob]

New fuel cap arrived a couple of days ago.
I do notice that if i remove the cap even after 5-10 miles journey, there is a loud succion noise.
Obvious vacuum problem here but don't know where to start looking.

Just for reminder, last time I ran the car with a "sealed" fuel cap, the fuel pump failed after a short 10 mile trip...

Is there a venting valve on the fuel tank that might need cleaning/replacement?

 

[varesecrazy]

New fuel cap arrived a couple of days ago.
I do notice that if i remove the cap even after 5-10 miles journey, there is a loud succion noise.
Obvious vacuum problem here but don't know where to start

Is there a venting valve on the fuel tank that might need cleaning/replacement?

Should be coloured tuning..black..and blue
Linking tank and filler neck

See ePER for panda details..

And mk2 punto section for my pics..

Charlie

 

[varesecrazy]

Should be coloured tuning..black..and blue
Linking tank and filler neck

See ePER for panda details..

And mk2 punto section for my pics..

Charlie

annoyingly I cannot find my old Punto "tank-removed" pics..

found these though..