Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - steve_Didcot

Fiesta fuel pump problem. 1996 Endura-E, 89k miles.

My fiesta failed to start after being left standing for a few weeks. Traced the problem to the fuel pump (1996 original). Voltage at connector 12V, connector in good condition. Mega ohms of resistance across the pump.

I replaced the pump with a new pump (3.5 ohm across pump). After re-fitting the new pump I could hear the pump prime before cranking and then the car turned over first time and ran fine for 5 mins (no coughing/sputtering). It accelerated ok, and pump whine sounded as usual.

The next day I completed the job (secured locking ring/replaced rear seat) but when trying to start found the pump had failed again. Turning on ignition no prime and resistance over pump 2100ohms. I'm guessing the pump failed as soon as I turned the ignition on or when turned ignition off after the original test after fitting.

Not sure how many amps the pump pulled but I'm guessing the pump (as original) has burned out. The fuel level is low (mid-reserve), so imagine cooling its ideal but wouldnt have thought that the pump would burn out immediately - or without a problem while running.

Any ideas / suggestions on identifying the fault appreciated.

Edited by steve_Didcot on 14/10/2013 at 01:47

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - steve_Didcot

of couse that should read 'cooling not ideal'

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - elekie&a/c doctor

Fuel pumps generally don't burn out .They go open circuit or high resistance.A pump on this car should draw approx 4-5 amps.If your pump has gone high resistance ,then I would suspect the brushes are not in complete contact wth the armature of the motor.It is possible that something in the fuel has contaminated the pump .hth

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - steve_Didcot

Thanks for reply. I assumed the pump couldn't have drawn too many amps from a 12V supply. The 4-5 amps sounds right given the resistance over the pump when it was installed. I just wondered if the 4-5 amps was enough to melt the internal motor wiring in such a short time without good cooling (ie pump immersed in fuel).

However, the fuel is pretty clean, no oil/water evident, and from a reputable suppier in the UK. A few chips of rust at the bottom of the tank but nothing that is going to get through the strainer to the pump.

Is it worth blowing out the fuel in the pump to remove fuel/potential contamination and re-fit?

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - dieselnut

If it's a brand new pump why not just return it as it's faulty. It might work again after handling if it's an intermittent fault. But the last thing you want is an unreliable fuel pump.

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - Peter.N.

3.5 ohms would equate to about 3-4 amps initially but I would suspect that the resistance increases when it starts turning. Its quite likely as the previous poster said that the brushes are not making contact either due to wear or corrosion.

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - jc2

Try connecting the pump to a power supply away from the vehicle-if it works,it could be an intermittent supply or earth to the tank.I had problems(not on a Fiesta)with a bad earth to the tank-adding a proper earth wire solved them.

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - steve_Didcot

Thanks all for suggestions.

I doubt wear/corrosion could have occured in such a short amount of time (less than 2 days); but could see contaminaiton at the brushes being an issue.

I will investigate contamination further. I will also look at the wiring to see if there is intermittent or low current on the 12V supply. I have a 12V supply in work to check independently.

Will get back with results - positive or negative to help resolve this /help others.

Ford Fiesta 1996 1.3 Endura-E, EFI - Ford Fiesta fuel pump failure - burning out pump - steve_Didcot

Conclusion is 'Fuel contamination'.

I am surprised as the fuel, though >1 year old, looks good. Its retained it straw yellow colour (not turned brown), and looks particle free, no oil sheen on the surface and no water layer below the petrol. However, as soon as it runs through a pump, and the pump is stopped; debris get trapped between the brushes and the armature. I suspect very, very fine rust particles.

Managed to clear the contacts in the original fuel pump (1995, 89k miles) by removing the strainer and manually rotating the turbine a couple of rotations in both directions. Resistance down from megaohms to 3 ohms. Now runs. With a 12V supply attached, motor pulls 1.5-1.8 amps with no load ie hoses disconnected and just pulling air.

I plan to clean the tank and replace the fuel. Expect that this will cure my problem. Will also replace fuel filter.

Take home message is, no matter how clean your fuel looks dont trust your eyes or old fuel.

Thanks all

Edited by steve_Didcot on 17/10/2013 at 03:43

 

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