Family issue with this car, its my brothers MK1 Focus.
(Not this actual one, but it's the same!)
Sadly I can't get to him for a while, so I thought I would post the issue here rather than in the Case Study section due to the lack of waveforms (for now), however with the right info and pointers perhaps I can turn it into a Case Study for our newsletter. Therefore I am asking for your assistance, any info/advice you can offer would be appreciated
Ok, so here's the deal:
Ford Focus Mk1 – 2000 (X) - 1.6 Petrol
On and off for a while now they've been having problems with the fuel pump in their Ford Focus.
Sometimes it blows the fuse, sometimes it doesn't, but either way what they end up with is a pump that isn't priming the system when the key is turned to the position before cranking.
After much retrying and general fiddling with the wires and gromet etc to the pump under the rear seat the pump will usually spring back into life, but there doesn't seem to be any rhyme or reason as to why / when this will happen.
At the weekend they had the recovery truck out as after the normal amount of fiddling the pump was still not playing. The guy did all the usual checks on the fuse, checking for supply etc, then lifted the rear seat and removed the large gromet that carries the wiring to the pump.
Disconnected the connector and checked the various connections using his meter. Again all the readings seemed correct, and when he reconnected it to the pump the pump primed and the car started fine.
However, my brother's wife (who drives the car the most) has now reported that the car feels 'lumpy' and 'hesitant' so it could be that the fuel pump is on it's last legs.
I offered to scope the car before, but due to it being such an intermittent issue he never saw the point as he said the fault wouldn't appear knowing his luck. Now his wife reports poor running, I am thinking its time to swoop in....
So ideas... ? If you believe it's the fuel pump, thats fine... if you think further investigation is required, please advise
Given you say "general fiddling with the wires and gromet etc to the pump under the rear seat the pump will usually spring back into life" - that 'suggests' a wiring fault.
Whittling that down to chaffed wire, broken/corroded strands or connector fault is the fun bit.
Being an Escort boy, I'd think on 'family line' of faults - so keep in mind fuse box and relay as other areas to check too.
(I've also seen the wires in the tank to be bare, where the coating had fallen away!)
So, my first point to scope from is the fuse box, where the wiring to the pump starts - or using two clips - scope at fuse box and at pump, so you have two waveforms to immediately compare.
A drive should hopefully get enough vibration in to induce the fault, if not - really giving the wires a shake should.
If the fault appears, but scoping shows little voltage change - then I'd look at pump side.
Otherwise the resulting waveforms should point to the next end of the chain to look.
Knows pre-2000 Fords and R33's better than the back of my own hand.
Anything newer... I'm probably driving it
Some additional information has come to light, DTCs. Now these were pulled from the car after the recovery chap had visited, during which time they had the pump disconnected whilst they cycled the key several times.
The codes have been cleared now to see if fresh ones are recorded, but here they are:
P0231 - Pump Secondary (Feedback) Circuit Low Voltage
P0232 - Pump Secondary (Feedback) Circuit High Voltage
I would deploy 3 Channels at the fuel pump connector end to get an idea whats happening first, power,ground & current.
Either way you will see what is shorting whether its to ground or positive, & also a look at the pumps internal integrity, as those codes suggest,but i would get it on IDS also to verify those two codes .
Hi Mike,
Re MK1 Focus, what you do have to watch on these which I've had a few times, is the 6pin block connector getting hot and giving trouble. In fairness the pumps probably knackered. I'll give you the info for the 6pin block connector on the fuel tank. PIN 1(1mm wire size) Green/Orange wire 'feed in' for fuel pump, PIN 2 (0.5mm wire size) White/Red from instrument panel, PIN 3 Not Used, PIN 4 (0.5mm wire size) Brown/Red to instrument panel, PIN 5 (1mm wire size) Black wire, Negative return/ Earth return for fuel pump goes to right hand A pillar (bolted at this point), PIN 6 (1mm wire size) Black wire, this is a splice into PIN 5 and is grounded with PIN 5 at the A Pillar. Fuel pump relay is K4 in CJB (Central Junction Box). Fuse supply to the secondary contacts for this relay is F12 (15Amp) also in CJB.